diff --git a/README.md b/README.md index b1756bb..4790fa3 100644 --- a/README.md +++ b/README.md @@ -1,2 +1,75 @@ -# google_AFL +# AFL 源码阅读项目 +## 项目介绍 + +本项目旨在深入研究和分析 American Fuzzy Lop (AFL) 的源代码。AFL 是一个强大的模糊测试工具，广泛用于发现软件中的安全漏洞。通过对 AFL 源代码的阅读和分析，我们希望能够更好地理解其工作原理、设计理念以及如何有效地使用该工具进行安全测试。 + +## 目标 + +- 理解 AFL 的核心算法和实现细节 +- 分析 AFL 在模糊测试中的应用 +- 探讨 AFL 的性能优化和扩展性 +- 编写项目报告，总结我们的发现和学习 + +## 目录结构 + +``` +project-root/ +├── src/ # 存放 AFL 源代码的目录 +├── doc/ # 存放项目文档和报告的目录 +└── README.md # 项目说明文件 +``` + +## 环境准备 + +在开始阅读和分析 AFL 源代码之前，请确保你的开发环境中已安装以下工具： + +- Git +- C 编译器（如 GCC） +- Make 工具 +- 其他依赖项（请参考 AFL 文档） + +## 获取源代码 + +要获取 AFL 的源代码，请使用以下命令： + +```bash +git clone https://github.com/google/AFL.git +``` + +## 编译和安装 AFL + +在 `src` 目录下，运行以下命令以编译和安装 AFL： + +```bash +cd src +make +``` + +编译完成后，AFL 的可执行文件将位于 `src` 目录中。 + +## 阅读分析 + +- 阅读 AFL 源代码，关注以下关键模块： + - **主循环**: 了解 AFL 如何管理模糊测试的整个流程。 + - **输入变异**: 分析 AFL 如何生成和变异测试用例。 + - **覆盖率跟踪**: 理解 AFL 如何收集代码覆盖率信息，以优化测试过程。 + +- 记录你的发现和疑问，准备在团队讨论中分享。 + +## 项目报告 + +在完成代码阅读和分析后，请编写项目报告，文件名为 `AFL_阅读报告.docx`，并将其放置在 `doc` 目录中。报告应包含以下内容： + +- 项目背景和目的 +- 关键模块的分析 +- 发现的关键问题和解决方案 +- 总结和未来工作 + +## 贡献 + +欢迎任何对本项目感兴趣的贡献者参与！如果你有建议或发现了问题，请通过提交 issue 或 pull request 的方式与我们联系。 + +## 许可证 + +本项目遵循 MIT 许可证。有关详细信息，请参阅 LICENSE 文件。 \ No newline at end of file diff --git a/src/.gitignore b/src/.gitignore new file mode 100644 index 0000000..57df30e --- /dev/null +++ b/src/.gitignore @@ -0,0 +1,20 @@ +# Binaries produced by "make". +afl-analyze +afl-as +afl-clang +afl-clang++ +afl-fuzz +afl-g++ +afl-gcc +afl-gotcpu +afl-showmap +afl-tmin +as + +# Binaries produced by "make -C llvm_mode" +afl-clang-fast +afl-clang-fast++ +afl-llvm-pass.so +afl-llvm-rt-32.o +afl-llvm-rt-64.o +afl-llvm-rt.o diff --git a/src/.travis.yml b/src/.travis.yml new file mode 100644 index 0000000..861728d --- /dev/null +++ b/src/.travis.yml @@ -0,0 +1,60 @@ +language: c + +env: + - AFL_I_DONT_CARE_ABOUT_MISSING_CRASHES=1 AFL_NO_UI=1 AFL_STOP_MANUALLY=1 + - AFL_I_DONT_CARE_ABOUT_MISSING_CRASHES=1 AFL_NO_UI=1 AFL_EXIT_WHEN_DONE=1 + # TODO: test AFL_BENCH_UNTIL_CRASH once we have a target that crashes + - AFL_I_DONT_CARE_ABOUT_MISSING_CRASHES=1 AFL_NO_UI=1 AFL_BENCH_JUST_ONE=1 + +before_install: + - sudo apt update + - sudo apt install -y libtool libtool-bin automake bison libglib2.0 + +# TODO: Look into splitting off some builds using a build matrix. +# TODO: Move this all into a bash script so we don't need to write bash in yaml. +script: + - make + - ./afl-gcc ./test-instr.c -o test-instr-gcc + - mkdir seeds + - echo "" > seeds/nil_seed + - if [ -z "$AFL_STOP_MANUALLY" ]; + then ./afl-fuzz -i seeds -o out/ -- ./test-instr-gcc; + else timeout --preserve-status 5s ./afl-fuzz -i seeds -o out/ -- ./test-instr-gcc; + fi + - .travis/check_fuzzer_stats.sh -o out -k peak_rss_mb -v 1 -p 3 + - rm -r out/* + - ./afl-clang ./test-instr.c -o test-instr-clang + - if [ -z "$AFL_STOP_MANUALLY" ]; + then ./afl-fuzz -i seeds -o out/ -- ./test-instr-clang; + else timeout --preserve-status 5s ./afl-fuzz -i seeds -o out/ -- ./test-instr-clang; + fi + - .travis/check_fuzzer_stats.sh -o out -k peak_rss_mb -v 1 -p 2 + - make clean + - CC=clang CXX=clang++ make + - cd llvm_mode + # TODO: Build with different versions of clang/LLVM since LLVM passes don't + # have a stable API. + - CC=clang CXX=clang++ LLVM_CONFIG=llvm-config make + - cd .. + - rm -r out/* + - ./afl-clang-fast ./test-instr.c -o test-instr-clang-fast + - if [ -z "$AFL_STOP_MANUALLY" ]; + then ./afl-fuzz -i seeds -o out/ -- ./test-instr-clang-fast; + else timeout --preserve-status 5s ./afl-fuzz -i seeds -o out/ -- ./test-instr-clang-fast; + fi + - .travis/check_fuzzer_stats.sh -o out -k peak_rss_mb -v 1 -p 3 + # Test fuzzing libFuzzer targets and trace-pc-guard instrumentation. + - clang -g -fsanitize-coverage=trace-pc-guard ./test-libfuzzer-target.c -c + - clang -c -w llvm_mode/afl-llvm-rt.o.c + - wget https://raw.githubusercontent.com/llvm/llvm-project/main/compiler-rt/lib/fuzzer/afl/afl_driver.cpp + - clang++ afl_driver.cpp afl-llvm-rt.o.o test-libfuzzer-target.o -o test-libfuzzer-target + - timeout --preserve-status 5s ./afl-fuzz -i seeds -o out/ -- ./test-libfuzzer-target + - cd qemu_mode + - ./build_qemu_support.sh + - cd .. + - gcc ./test-instr.c -o test-no-instr + - if [ -z "$AFL_STOP_MANUALLY" ]; + then ./afl-fuzz -Q -i seeds -o out/ -- ./test-no-instr; + else timeout --preserve-status 5s ./afl-fuzz -Q -i seeds -o out/ -- ./test-no-instr; + fi + - .travis/check_fuzzer_stats.sh -o out -k peak_rss_mb -v 12 -p 9 diff --git a/src/.travis/check_fuzzer_stats.sh b/src/.travis/check_fuzzer_stats.sh new file mode 100644 index 0000000..6fd6bd5 --- /dev/null +++ b/src/.travis/check_fuzzer_stats.sh @@ -0,0 +1,60 @@ +#!/bin/bash +usage() { + echo "Usage: $0 -o -k -v [-p ]" 1>&2; + echo " " 1>&2; + echo "Checks if a key:value appears in the fuzzer_stats report" 1>&2; + echo " " 1>&2; + echo -n "If \"value\" is numeric and \"precision\" is defined, checks if the stat " 1>&2; + echo "printed by afl is value+/-precision." 1>&2; + exit 1; } + +while getopts "o:k:v:p:" opt; do + case "${opt}" in + o) + o=${OPTARG} + ;; + k) + k=${OPTARG} + ;; + v) + v=${OPTARG} + ;; + p) + p=${OPTARG} + ;; + *) + usage + ;; + esac +done + +if [ -z $o ] || [ -z $k ] || [ -z $v ]; then usage; fi + +# xargs to trim the surrounding whitespaces +stat_v=$( grep $k "$o"/fuzzer_stats | cut -d ":" -f 2 | xargs ) +v=$( echo "$v" | xargs ) + +if [ -z stat_v ]; + then echo "ERROR: key $k not found in fuzzer_stats." 1>&2 + exit 1 +fi + +re_percent='^[0-9]+([.][0-9]+)?\%$' +# if the argument is a number in percentage, get rid of the % +if [[ "$v" =~ $re_percent ]]; then v=${v: :-1}; fi +if [[ "$stat_v" =~ $re_percent ]]; then stat_v=${stat_v: :-1}; fi + +re_numeric='^[0-9]+([.][0-9]+)?$' +# if the argument is not a number, we check for strict equality +if (! [[ "$v" =~ $re_numeric ]]) || (! [[ "$stat_v" =~ $re ]]); + then if [ "$v" != "$stat_v" ]; + then echo "ERROR: \"$k:$stat_v\" (should be $v)." 1>&2 + exit 2; + fi +# checks if the stat reported by afl is in the range +elif [ "$stat_v" -lt $(( v - p )) ] || [ "$stat_v" -gt $(( v + p )) ]; + then echo "ERROR: key $k:$stat_v is out of correct range." 1>&2 + exit 3; +fi +echo "OK: key $k:$stat_v" 1>&2 + diff --git a/src/AFL b/src/AFL deleted file mode 160000 index 6103710..0000000 --- a/src/AFL +++ /dev/null @@ -1 +0,0 @@ -Subproject commit 61037103ae3722c8060ff7082994836a794f978e diff --git a/src/Android.bp b/src/Android.bp new file mode 100644 index 0000000..9fdf6f0 --- /dev/null +++ b/src/Android.bp @@ -0,0 +1,140 @@ +cc_defaults { + name: "afl-defaults", + + cflags: [ + "-funroll-loops", + "-Wno-pointer-sign", + "-Wno-pointer-arith", + "-Wno-sign-compare", + "-Wno-unused-parameter", + "-Wno-unused-function", + "-Wno-format", + "-Wno-user-defined-warnings", + "-DUSE_TRACE_PC=1", + "-DBIN_PATH=\"out/host/linux-x86/bin\"", + "-DDOC_PATH=\"out/host/linux-x86/shared/doc/afl\"", + "-D__USE_GNU", + ], +} + +cc_binary { + name: "afl-fuzz", + static_executable: true, + host_supported: true, + + defaults: [ + "afl-defaults", + ], + + srcs: [ + "afl-fuzz.c", + ], +} + +cc_binary { + name: "afl-showmap", + static_executable: true, + host_supported: true, + + defaults: [ + "afl-defaults", + ], + + srcs: [ + "afl-showmap.c", + ], +} + +cc_binary { + name: "afl-tmin", + static_executable: true, + host_supported: true, + + defaults: [ + "afl-defaults", + ], + + srcs: [ + "afl-tmin.c", + ], +} + +cc_binary { + name: "afl-analyze", + static_executable: true, + host_supported: true, + + defaults: [ + "afl-defaults", + ], + + srcs: [ + "afl-analyze.c", + ], +} + +cc_binary { + name: "afl-gotcpu", + static_executable: true, + host_supported: true, + + defaults: [ + "afl-defaults", + ], + + srcs: [ + "afl-gotcpu.c", + ], +} + +cc_binary_host { + name: "afl-clang-fast", + static_executable: true, + + defaults: [ + "afl-defaults", + ], + + cflags: [ + "-D__ANDROID__", + "-DAFL_PATH=\"out/host/linux-x86/lib64\"", + ], + + srcs: [ + "llvm_mode/afl-clang-fast.c", + ], +} + +cc_binary_host { + name: "afl-clang-fast++", + static_executable: true, + + defaults: [ + "afl-defaults", + ], + + cflags: [ + "-D__ANDROID__", + "-DAFL_PATH=\"out/host/linux-x86/lib64\"", + ], + + srcs: [ + "llvm_mode/afl-clang-fast.c", + ], +} + +cc_library_static { + name: "afl-llvm-rt", + compile_multilib: "both", + vendor_available: true, + host_supported: true, + recovery_available: true, + + defaults: [ + "afl-defaults", + ], + + srcs: [ + "llvm_mode/afl-llvm-rt.o.c", + ], +} diff --git a/src/CONTRIBUTING.md b/src/CONTRIBUTING.md new file mode 100644 index 0000000..939e534 --- /dev/null +++ b/src/CONTRIBUTING.md @@ -0,0 +1,28 @@ +# How to Contribute + +We'd love to accept your patches and contributions to this project. 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We also recommend that a + file or class name and description of purpose be included on the + same "printed page" as the copyright notice for easier + identification within third-party archives. + + Copyright [yyyy] [name of copyright owner] + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. diff --git a/src/Makefile b/src/Makefile new file mode 100644 index 0000000..3819312 --- /dev/null +++ b/src/Makefile @@ -0,0 +1,153 @@ +# +# american fuzzy lop - makefile +# ----------------------------- +# +# Written and maintained by Michal Zalewski +# +# Copyright 2013, 2014, 2015, 2016, 2017 Google LLC All rights reserved. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at: +# +# http://www.apache.org/licenses/LICENSE-2.0 +# + +PROGNAME = afl +VERSION = $(shell grep '^\#define VERSION ' config.h | cut -d '"' -f2) + +PREFIX ?= /usr/local +BIN_PATH = $(PREFIX)/bin +HELPER_PATH = $(PREFIX)/lib/afl +DOC_PATH = $(PREFIX)/share/doc/afl +MISC_PATH = $(PREFIX)/share/afl + +# PROGS intentionally omit afl-as, which gets installed elsewhere. + +PROGS = afl-gcc afl-fuzz afl-showmap afl-tmin afl-gotcpu afl-analyze +SH_PROGS = afl-plot afl-cmin afl-whatsup + +CFLAGS ?= -O3 -funroll-loops +CFLAGS += -Wall -D_FORTIFY_SOURCE=2 -g -Wno-pointer-sign \ + -DAFL_PATH=\"$(HELPER_PATH)\" -DDOC_PATH=\"$(DOC_PATH)\" \ + -DBIN_PATH=\"$(BIN_PATH)\" + +ifneq "$(filter Linux GNU%,$(shell uname))" "" + LDFLAGS += -ldl +endif + +ifeq "$(findstring clang, $(shell $(CC) --version 2>/dev/null))" "" + TEST_CC = afl-gcc +else + TEST_CC = afl-clang +endif + +COMM_HDR = alloc-inl.h config.h debug.h types.h + +all: test_x86 $(PROGS) afl-as test_build all_done + +ifndef AFL_NO_X86 + +test_x86: + @echo "[*] Checking for the ability to compile x86 code..." + @echo 'main() { __asm__("xorb %al, %al"); }' | $(CC) -w -x c - -o .test || ( echo; echo "Oops, looks like your compiler can't generate x86 code."; echo; echo "Don't panic! You can use the LLVM or QEMU mode, but see docs/INSTALL first."; echo "(To ignore this error, set AFL_NO_X86=1 and try again.)"; echo; exit 1 ) + @rm -f .test + @echo "[+] Everything seems to be working, ready to compile." + +else + +test_x86: + @echo "[!] Note: skipping x86 compilation checks (AFL_NO_X86 set)." + +endif + +afl-gcc: afl-gcc.c $(COMM_HDR) | test_x86 + $(CC) $(CFLAGS) $@.c -o $@ $(LDFLAGS) + set -e; for i in afl-g++ afl-clang afl-clang++; do ln -sf afl-gcc $$i; done + +afl-as: afl-as.c afl-as.h $(COMM_HDR) | test_x86 + $(CC) $(CFLAGS) $@.c -o $@ $(LDFLAGS) + ln -sf afl-as as + +afl-fuzz: afl-fuzz.c $(COMM_HDR) | test_x86 + $(CC) $(CFLAGS) $@.c -o $@ $(LDFLAGS) + +afl-showmap: afl-showmap.c $(COMM_HDR) | test_x86 + $(CC) $(CFLAGS) $@.c -o $@ $(LDFLAGS) + +afl-tmin: afl-tmin.c $(COMM_HDR) | test_x86 + $(CC) $(CFLAGS) $@.c -o $@ $(LDFLAGS) + +afl-analyze: afl-analyze.c $(COMM_HDR) | test_x86 + $(CC) $(CFLAGS) $@.c -o $@ $(LDFLAGS) + +afl-gotcpu: afl-gotcpu.c $(COMM_HDR) | test_x86 + $(CC) $(CFLAGS) $@.c -o $@ $(LDFLAGS) + +ifndef AFL_NO_X86 + +test_build: afl-gcc afl-as afl-showmap + @echo "[*] Testing the CC wrapper and instrumentation output..." + unset AFL_USE_ASAN AFL_USE_MSAN; AFL_QUIET=1 AFL_INST_RATIO=100 AFL_PATH=. ./$(TEST_CC) $(CFLAGS) test-instr.c -o test-instr $(LDFLAGS) + ./afl-showmap -m none -q -o .test-instr0 ./test-instr < /dev/null + echo 1 | ./afl-showmap -m none -q -o .test-instr1 ./test-instr + @rm -f test-instr + @cmp -s .test-instr0 .test-instr1; DR="$$?"; rm -f .test-instr0 .test-instr1; if [ "$$DR" = "0" ]; then echo; echo "Oops, the instrumentation does not seem to be behaving correctly!"; echo; echo "Please ping to troubleshoot the issue."; echo; exit 1; fi + @echo "[+] All right, the instrumentation seems to be working!" + +else + +test_build: afl-gcc afl-as afl-showmap + @echo "[!] Note: skipping build tests (you may need to use LLVM or QEMU mode)." + +endif + +all_done: test_build + @if [ ! "`which clang 2>/dev/null`" = "" ]; then echo "[+] LLVM users: see llvm_mode/README.llvm for a faster alternative to afl-gcc."; fi + @echo "[+] All done! Be sure to review README - it's pretty short and useful." + @if [ "`uname`" = "Darwin" ]; then printf "\nWARNING: Fuzzing on MacOS X is slow because of the unusually high overhead of\nfork() on this OS. Consider using Linux or *BSD. You can also use VirtualBox\n(virtualbox.org) to put AFL inside a Linux or *BSD VM.\n\n"; fi + @! tty <&1 >/dev/null || printf "\033[0;30mNOTE: If you can read this, your terminal probably uses white background.\nThis will make the UI hard to read. See docs/status_screen.txt for advice.\033[0m\n" 2>/dev/null + +.NOTPARALLEL: clean + +clean: + rm -f $(PROGS) afl-as as afl-g++ afl-clang afl-clang++ *.o *~ a.out core core.[1-9][0-9]* *.stackdump test .test test-instr .test-instr0 .test-instr1 qemu_mode/qemu-2.10.0.tar.bz2 afl-qemu-trace + rm -rf out_dir qemu_mode/qemu-2.10.0 + $(MAKE) -C llvm_mode clean + $(MAKE) -C libdislocator clean + $(MAKE) -C libtokencap clean + +install: all + mkdir -p -m 755 $${DESTDIR}$(BIN_PATH) $${DESTDIR}$(HELPER_PATH) $${DESTDIR}$(DOC_PATH) $${DESTDIR}$(MISC_PATH) + rm -f $${DESTDIR}$(BIN_PATH)/afl-plot.sh + install -m 755 $(PROGS) $(SH_PROGS) $${DESTDIR}$(BIN_PATH) + rm -f $${DESTDIR}$(BIN_PATH)/afl-as + if [ -f afl-qemu-trace ]; then install -m 755 afl-qemu-trace $${DESTDIR}$(BIN_PATH); fi +ifndef AFL_TRACE_PC + if [ -f afl-clang-fast -a -f afl-llvm-pass.so -a -f afl-llvm-rt.o ]; then set -e; install -m 755 afl-clang-fast $${DESTDIR}$(BIN_PATH); ln -sf afl-clang-fast $${DESTDIR}$(BIN_PATH)/afl-clang-fast++; install -m 755 afl-llvm-pass.so afl-llvm-rt.o $${DESTDIR}$(HELPER_PATH); fi +else + if [ -f afl-clang-fast -a -f afl-llvm-rt.o ]; then set -e; install -m 755 afl-clang-fast $${DESTDIR}$(BIN_PATH); ln -sf afl-clang-fast $${DESTDIR}$(BIN_PATH)/afl-clang-fast++; install -m 755 afl-llvm-rt.o $${DESTDIR}$(HELPER_PATH); fi +endif + if [ -f afl-llvm-rt-32.o ]; then set -e; install -m 755 afl-llvm-rt-32.o $${DESTDIR}$(HELPER_PATH); fi + if [ -f afl-llvm-rt-64.o ]; then set -e; install -m 755 afl-llvm-rt-64.o $${DESTDIR}$(HELPER_PATH); fi + set -e; for i in afl-g++ afl-clang afl-clang++; do ln -sf afl-gcc $${DESTDIR}$(BIN_PATH)/$$i; done + install -m 755 afl-as $${DESTDIR}$(HELPER_PATH) + ln -sf afl-as $${DESTDIR}$(HELPER_PATH)/as + install -m 644 README.md docs/ChangeLog docs/*.txt $${DESTDIR}$(DOC_PATH) + cp -r testcases/ $${DESTDIR}$(MISC_PATH) + cp -r dictionaries/ $${DESTDIR}$(MISC_PATH) + +publish: clean + test "`basename $$PWD`" = "AFL" || exit 1 + test -f ~/www/afl/releases/$(PROGNAME)-$(VERSION).tgz; if [ "$$?" = "0" ]; then echo; echo "Change program version in config.h, mmkay?"; echo; exit 1; fi + cd ..; rm -rf $(PROGNAME)-$(VERSION); cp -pr $(PROGNAME) $(PROGNAME)-$(VERSION); \ + tar -cvz -f ~/www/afl/releases/$(PROGNAME)-$(VERSION).tgz $(PROGNAME)-$(VERSION) + chmod 644 ~/www/afl/releases/$(PROGNAME)-$(VERSION).tgz + ( cd ~/www/afl/releases/; ln -s -f $(PROGNAME)-$(VERSION).tgz $(PROGNAME)-latest.tgz ) + cat docs/README >~/www/afl/README.txt + cat docs/status_screen.txt >~/www/afl/status_screen.txt + cat docs/historical_notes.txt >~/www/afl/historical_notes.txt + cat docs/technical_details.txt >~/www/afl/technical_details.txt + cat docs/ChangeLog >~/www/afl/ChangeLog.txt + cat docs/QuickStartGuide.txt >~/www/afl/QuickStartGuide.txt + echo -n "$(VERSION)" >~/www/afl/version.txt diff --git a/src/README.md b/src/README.md new file mode 100644 index 0000000..49960b9 --- /dev/null +++ b/src/README.md @@ -0,0 +1,493 @@ +# american fuzzy lop + +[![Build Status](https://travis-ci.org/google/AFL.svg?branch=master)](https://travis-ci.org/google/AFL) + +Originally developed by Michal Zalewski . + +See [QuickStartGuide.txt](docs/QuickStartGuide.txt) if you don't have time to read +this file. + +## 1) Challenges of guided fuzzing + +Fuzzing is one of the most powerful and proven strategies for identifying +security issues in real-world software; it is responsible for the vast +majority of remote code execution and privilege escalation bugs found to date +in security-critical software. + +Unfortunately, fuzzing is also relatively shallow; blind, random mutations +make it very unlikely to reach certain code paths in the tested code, leaving +some vulnerabilities firmly outside the reach of this technique. + +There have been numerous attempts to solve this problem. One of the early +approaches - pioneered by Tavis Ormandy - is corpus distillation. The method +relies on coverage signals to select a subset of interesting seeds from a +massive, high-quality corpus of candidate files, and then fuzz them by +traditional means. The approach works exceptionally well, but requires such +a corpus to be readily available. In addition, block coverage measurements +provide only a very simplistic understanding of program state, and are less +useful for guiding the fuzzing effort in the long haul. + +Other, more sophisticated research has focused on techniques such as program +flow analysis ("concolic execution"), symbolic execution, or static analysis. +All these methods are extremely promising in experimental settings, but tend +to suffer from reliability and performance problems in practical uses - and +currently do not offer a viable alternative to "dumb" fuzzing techniques. + +## 2) The afl-fuzz approach + +American Fuzzy Lop is a brute-force fuzzer coupled with an exceedingly simple +but rock-solid instrumentation-guided genetic algorithm. It uses a modified +form of edge coverage to effortlessly pick up subtle, local-scale changes to +program control flow. + +Simplifying a bit, the overall algorithm can be summed up as: + + 1) Load user-supplied initial test cases into the queue, + + 2) Take next input file from the queue, + + 3) Attempt to trim the test case to the smallest size that doesn't alter + the measured behavior of the program, + + 4) Repeatedly mutate the file using a balanced and well-researched variety + of traditional fuzzing strategies, + + 5) If any of the generated mutations resulted in a new state transition + recorded by the instrumentation, add mutated output as a new entry in the + queue. + + 6) Go to 2. + +The discovered test cases are also periodically culled to eliminate ones that +have been obsoleted by newer, higher-coverage finds; and undergo several other +instrumentation-driven effort minimization steps. + +As a side result of the fuzzing process, the tool creates a small, +self-contained corpus of interesting test cases. These are extremely useful +for seeding other, labor- or resource-intensive testing regimes - for example, +for stress-testing browsers, office applications, graphics suites, or +closed-source tools. + +The fuzzer is thoroughly tested to deliver out-of-the-box performance far +superior to blind fuzzing or coverage-only tools. + +## 3) Instrumenting programs for use with AFL + +When source code is available, instrumentation can be injected by a companion +tool that works as a drop-in replacement for gcc or clang in any standard build +process for third-party code. + +The instrumentation has a fairly modest performance impact; in conjunction with +other optimizations implemented by afl-fuzz, most programs can be fuzzed as fast +or even faster than possible with traditional tools. + +The correct way to recompile the target program may vary depending on the +specifics of the build process, but a nearly-universal approach would be: + +```shell +$ CC=/path/to/afl/afl-gcc ./configure +$ make clean all +``` + +For C++ programs, you'd would also want to set `CXX=/path/to/afl/afl-g++`. + +The clang wrappers (afl-clang and afl-clang++) can be used in the same way; +clang users may also opt to leverage a higher-performance instrumentation mode, +as described in llvm_mode/README.llvm. + +When testing libraries, you need to find or write a simple program that reads +data from stdin or from a file and passes it to the tested library. In such a +case, it is essential to link this executable against a static version of the +instrumented library, or to make sure that the correct .so file is loaded at +runtime (usually by setting `LD_LIBRARY_PATH`). The simplest option is a static +build, usually possible via: + +```shell +$ CC=/path/to/afl/afl-gcc ./configure --disable-shared +``` + +Setting `AFL_HARDEN=1` when calling 'make' will cause the CC wrapper to +automatically enable code hardening options that make it easier to detect +simple memory bugs. Libdislocator, a helper library included with AFL (see +libdislocator/README.dislocator) can help uncover heap corruption issues, too. + +PS. ASAN users are advised to review [notes_for_asan.txt](docs/notes_for_asan.txt) file for important +caveats. + +## 4) Instrumenting binary-only apps + +When source code is *NOT* available, the fuzzer offers experimental support for +fast, on-the-fly instrumentation of black-box binaries. This is accomplished +with a version of QEMU running in the lesser-known "user space emulation" mode. + +QEMU is a project separate from AFL, but you can conveniently build the +feature by doing: + +```shell +$ cd qemu_mode +$ ./build_qemu_support.sh +``` + +For additional instructions and caveats, see qemu_mode/README.qemu. + +The mode is approximately 2-5x slower than compile-time instrumentation, is +less conducive to parallelization, and may have some other quirks. + +## 5) Choosing initial test cases + +To operate correctly, the fuzzer requires one or more starting file that +contains a good example of the input data normally expected by the targeted +application. There are two basic rules: + + - Keep the files small. Under 1 kB is ideal, although not strictly necessary. + For a discussion of why size matters, see [perf_tips.txt](docs/perf_tips.txt). + + - Use multiple test cases only if they are functionally different from + each other. There is no point in using fifty different vacation photos + to fuzz an image library. + +You can find many good examples of starting files in the testcases/ subdirectory +that comes with this tool. + +PS. If a large corpus of data is available for screening, you may want to use +the afl-cmin utility to identify a subset of functionally distinct files that +exercise different code paths in the target binary. + +## 6) Fuzzing binaries + +The fuzzing process itself is carried out by the afl-fuzz utility. This program +requires a read-only directory with initial test cases, a separate place to +store its findings, plus a path to the binary to test. + +For target binaries that accept input directly from stdin, the usual syntax is: + +```shell +$ ./afl-fuzz -i testcase_dir -o findings_dir /path/to/program [...params...] +``` + +For programs that take input from a file, use '@@' to mark the location in +the target's command line where the input file name should be placed. The +fuzzer will substitute this for you: + +```shell +$ ./afl-fuzz -i testcase_dir -o findings_dir /path/to/program @@ +``` + +You can also use the -f option to have the mutated data written to a specific +file. This is useful if the program expects a particular file extension or so. + +Non-instrumented binaries can be fuzzed in the QEMU mode (add -Q in the command +line) or in a traditional, blind-fuzzer mode (specify -n). + +You can use -t and -m to override the default timeout and memory limit for the +executed process; rare examples of targets that may need these settings touched +include compilers and video decoders. + +Tips for optimizing fuzzing performance are discussed in [perf_tips.txt](docs/perf_tips.txt). + +Note that afl-fuzz starts by performing an array of deterministic fuzzing +steps, which can take several days, but tend to produce neat test cases. If you +want quick & dirty results right away - akin to zzuf and other traditional +fuzzers - add the -d option to the command line. + +## 7) Interpreting output + +See the [status_screen.txt](docs/status_screen.txt) file for information on +how to interpret the displayed stats and monitor the health of the process. +Be sure to consult this file especially if any UI elements are highlighted in +red. + +The fuzzing process will continue until you press Ctrl-C. At minimum, you want +to allow the fuzzer to complete one queue cycle, which may take anywhere from a +couple of hours to a week or so. + +There are three subdirectories created within the output directory and updated +in real time: + + - queue/ - test cases for every distinctive execution path, plus all the + starting files given by the user. This is the synthesized corpus + mentioned in section 2. + Before using this corpus for any other purposes, you can shrink + it to a smaller size using the afl-cmin tool. The tool will find + a smaller subset of files offering equivalent edge coverage. + + - crashes/ - unique test cases that cause the tested program to receive a + fatal signal (e.g., SIGSEGV, SIGILL, SIGABRT). The entries are + grouped by the received signal. + + - hangs/ - unique test cases that cause the tested program to time out. The + default time limit before something is classified as a hang is + the larger of 1 second and the value of the -t parameter. + The value can be fine-tuned by setting AFL_HANG_TMOUT, but this + is rarely necessary. + +Crashes and hangs are considered "unique" if the associated execution paths +involve any state transitions not seen in previously-recorded faults. If a +single bug can be reached in multiple ways, there will be some count inflation +early in the process, but this should quickly taper off. + +The file names for crashes and hangs are correlated with parent, non-faulting +queue entries. This should help with debugging. + +When you can't reproduce a crash found by afl-fuzz, the most likely cause is +that you are not setting the same memory limit as used by the tool. Try: + +```shell +$ LIMIT_MB=50 +$ ( ulimit -Sv $[LIMIT_MB << 10]; /path/to/tested_binary ... ) +``` + +Change LIMIT_MB to match the -m parameter passed to afl-fuzz. On OpenBSD, +also change -Sv to -Sd. + +Any existing output directory can be also used to resume aborted jobs; try: + +```shell +$ ./afl-fuzz -i- -o existing_output_dir [...etc...] +``` + +If you have gnuplot installed, you can also generate some pretty graphs for any +active fuzzing task using afl-plot. For an example of how this looks like, +see [http://lcamtuf.coredump.cx/afl/plot/](http://lcamtuf.coredump.cx/afl/plot/). + +## 8) Parallelized fuzzing + +Every instance of afl-fuzz takes up roughly one core. This means that on +multi-core systems, parallelization is necessary to fully utilize the hardware. +For tips on how to fuzz a common target on multiple cores or multiple networked +machines, please refer to [parallel_fuzzing.txt](docs/parallel_fuzzing.txt). + +The parallel fuzzing mode also offers a simple way for interfacing AFL to other +fuzzers, to symbolic or concolic execution engines, and so forth; again, see the +last section of [parallel_fuzzing.txt](docs/parallel_fuzzing.txt) for tips. + +## 9) Fuzzer dictionaries + +By default, afl-fuzz mutation engine is optimized for compact data formats - +say, images, multimedia, compressed data, regular expression syntax, or shell +scripts. It is somewhat less suited for languages with particularly verbose and +redundant verbiage - notably including HTML, SQL, or JavaScript. + +To avoid the hassle of building syntax-aware tools, afl-fuzz provides a way to +seed the fuzzing process with an optional dictionary of language keywords, +magic headers, or other special tokens associated with the targeted data type +-- and use that to reconstruct the underlying grammar on the go: + + [http://lcamtuf.blogspot.com/2015/01/afl-fuzz-making-up-grammar-with.html](http://lcamtuf.blogspot.com/2015/01/afl-fuzz-making-up-grammar-with.html) + +To use this feature, you first need to create a dictionary in one of the two +formats discussed in dictionaries/README.dictionaries; and then point the fuzzer +to it via the -x option in the command line. + +(Several common dictionaries are already provided in that subdirectory, too.) + +There is no way to provide more structured descriptions of the underlying +syntax, but the fuzzer will likely figure out some of this based on the +instrumentation feedback alone. This actually works in practice, say: + + [http://lcamtuf.blogspot.com/2015/04/finding-bugs-in-sqlite-easy-way.html](http://lcamtuf.blogspot.com/2015/04/finding-bugs-in-sqlite-easy-way.html) + +PS. Even when no explicit dictionary is given, afl-fuzz will try to extract +existing syntax tokens in the input corpus by watching the instrumentation +very closely during deterministic byte flips. This works for some types of +parsers and grammars, but isn't nearly as good as the -x mode. + +If a dictionary is really hard to come by, another option is to let AFL run +for a while, and then use the token capture library that comes as a companion +utility with AFL. For that, see libtokencap/README.tokencap. + +## 10) Crash triage + +The coverage-based grouping of crashes usually produces a small data set that +can be quickly triaged manually or with a very simple GDB or Valgrind script. +Every crash is also traceable to its parent non-crashing test case in the +queue, making it easier to diagnose faults. + +Having said that, it's important to acknowledge that some fuzzing crashes can be +difficult to quickly evaluate for exploitability without a lot of debugging and +code analysis work. To assist with this task, afl-fuzz supports a very unique +"crash exploration" mode enabled with the -C flag. + +In this mode, the fuzzer takes one or more crashing test cases as the input, +and uses its feedback-driven fuzzing strategies to very quickly enumerate all +code paths that can be reached in the program while keeping it in the +crashing state. + +Mutations that do not result in a crash are rejected; so are any changes that +do not affect the execution path. + +The output is a small corpus of files that can be very rapidly examined to see +what degree of control the attacker has over the faulting address, or whether +it is possible to get past an initial out-of-bounds read - and see what lies +beneath. + +Oh, one more thing: for test case minimization, give afl-tmin a try. The tool +can be operated in a very simple way: + +```shell +$ ./afl-tmin -i test_case -o minimized_result -- /path/to/program [...] +``` + +The tool works with crashing and non-crashing test cases alike. In the crash +mode, it will happily accept instrumented and non-instrumented binaries. In the +non-crashing mode, the minimizer relies on standard AFL instrumentation to make +the file simpler without altering the execution path. + +The minimizer accepts the -m, -t, -f and @@ syntax in a manner compatible with +afl-fuzz. + +Another recent addition to AFL is the afl-analyze tool. It takes an input +file, attempts to sequentially flip bytes, and observes the behavior of the +tested program. It then color-codes the input based on which sections appear to +be critical, and which are not; while not bulletproof, it can often offer quick +insights into complex file formats. More info about its operation can be found +near the end of [technical_details.txt](docs/technical_details.txt). + +## 11) Going beyond crashes + +Fuzzing is a wonderful and underutilized technique for discovering non-crashing +design and implementation errors, too. Quite a few interesting bugs have been +found by modifying the target programs to call abort() when, say: + + - Two bignum libraries produce different outputs when given the same + fuzzer-generated input, + + - An image library produces different outputs when asked to decode the same + input image several times in a row, + + - A serialization / deserialization library fails to produce stable outputs + when iteratively serializing and deserializing fuzzer-supplied data, + + - A compression library produces an output inconsistent with the input file + when asked to compress and then decompress a particular blob. + +Implementing these or similar sanity checks usually takes very little time; +if you are the maintainer of a particular package, you can make this code +conditional with `#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION` (a flag also +shared with libfuzzer) or `#ifdef __AFL_COMPILER` (this one is just for AFL). + +## 12) Common-sense risks + +Please keep in mind that, similarly to many other computationally-intensive +tasks, fuzzing may put strain on your hardware and on the OS. In particular: + + - Your CPU will run hot and will need adequate cooling. In most cases, if + cooling is insufficient or stops working properly, CPU speeds will be + automatically throttled. That said, especially when fuzzing on less + suitable hardware (laptops, smartphones, etc), it's not entirely impossible + for something to blow up. + + - Targeted programs may end up erratically grabbing gigabytes of memory or + filling up disk space with junk files. AFL tries to enforce basic memory + limits, but can't prevent each and every possible mishap. The bottom line + is that you shouldn't be fuzzing on systems where the prospect of data loss + is not an acceptable risk. + + - Fuzzing involves billions of reads and writes to the filesystem. On modern + systems, this will be usually heavily cached, resulting in fairly modest + "physical" I/O - but there are many factors that may alter this equation. + It is your responsibility to monitor for potential trouble; with very heavy + I/O, the lifespan of many HDDs and SSDs may be reduced. + + A good way to monitor disk I/O on Linux is the 'iostat' command: + +```shell + $ iostat -d 3 -x -k [...optional disk ID...] +``` + +## 13) Known limitations & areas for improvement + +Here are some of the most important caveats for AFL: + + - AFL detects faults by checking for the first spawned process dying due to + a signal (SIGSEGV, SIGABRT, etc). Programs that install custom handlers for + these signals may need to have the relevant code commented out. In the same + vein, faults in child processed spawned by the fuzzed target may evade + detection unless you manually add some code to catch that. + + - As with any other brute-force tool, the fuzzer offers limited coverage if + encryption, checksums, cryptographic signatures, or compression are used to + wholly wrap the actual data format to be tested. + + To work around this, you can comment out the relevant checks (see + experimental/libpng_no_checksum/ for inspiration); if this is not possible, + you can also write a postprocessor, as explained in + experimental/post_library/. + + - There are some unfortunate trade-offs with ASAN and 64-bit binaries. This + isn't due to any specific fault of afl-fuzz; see [notes_for_asan.txt](docs/notes_for_asan.txt) + for tips. + + - There is no direct support for fuzzing network services, background + daemons, or interactive apps that require UI interaction to work. You may + need to make simple code changes to make them behave in a more traditional + way. Preeny may offer a relatively simple option, too - see: + https://github.com/zardus/preeny + + Some useful tips for modifying network-based services can be also found at: + https://www.fastly.com/blog/how-to-fuzz-server-american-fuzzy-lop + + - AFL doesn't output human-readable coverage data. If you want to monitor + coverage, use afl-cov from Michael Rash: https://github.com/mrash/afl-cov + + - Occasionally, sentient machines rise against their creators. If this + happens to you, please consult http://lcamtuf.coredump.cx/prep/. + +Beyond this, see INSTALL for platform-specific tips. + +## 14) Special thanks + +Many of the improvements to afl-fuzz wouldn't be possible without feedback, +bug reports, or patches from: + +``` + Jann Horn Hanno Boeck + Felix Groebert Jakub Wilk + Richard W. M. Jones Alexander Cherepanov + Tom Ritter Hovik Manucharyan + Sebastian Roschke Eberhard Mattes + Padraig Brady Ben Laurie + @dronesec Luca Barbato + Tobias Ospelt Thomas Jarosch + Martin Carpenter Mudge Zatko + Joe Zbiciak Ryan Govostes + Michael Rash William Robinet + Jonathan Gray Filipe Cabecinhas + Nico Weber Jodie Cunningham + Andrew Griffiths Parker Thompson + Jonathan Neuschfer Tyler Nighswander + Ben Nagy Samir Aguiar + Aidan Thornton Aleksandar Nikolich + Sam Hakim Laszlo Szekeres + David A. Wheeler Turo Lamminen + Andreas Stieger Richard Godbee + Louis Dassy teor2345 + Alex Moneger Dmitry Vyukov + Keegan McAllister Kostya Serebryany + Richo Healey Martijn Bogaard + rc0r Jonathan Foote + Christian Holler Dominique Pelle + Jacek Wielemborek Leo Barnes + Jeremy Barnes Jeff Trull + Guillaume Endignoux ilovezfs + Daniel Godas-Lopez Franjo Ivancic + Austin Seipp Daniel Komaromy + Daniel Binderman Jonathan Metzman + Vegard Nossum Jan Kneschke + Kurt Roeckx Marcel Bohme + Van-Thuan Pham Abhik Roychoudhury + Joshua J. Drake Toby Hutton + Rene Freingruber Sergey Davidoff + Sami Liedes Craig Young + Andrzej Jackowski Daniel Hodson +``` + +Thank you! + +## 15) Contact + +Questions? Concerns? Bug reports? Please use GitHub. + +There is also a mailing list for the project; to join, send a mail to +. Or, if you prefer to browse +archives first, try: [https://groups.google.com/group/afl-users](https://groups.google.com/group/afl-users). diff --git a/src/afl-analyze.c b/src/afl-analyze.c new file mode 100644 index 0000000..c97b73d --- /dev/null +++ b/src/afl-analyze.c @@ -0,0 +1,1095 @@ +/* + Copyright 2016 Google LLC All rights reserved. + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at: + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +*/ + +/* + american fuzzy lop - file format analyzer + ----------------------------------------- + + Written and maintained by Michal Zalewski + + A nifty utility that grabs an input file and takes a stab at explaining + its structure by observing how changes to it affect the execution path. + + If the output scrolls past the edge of the screen, pipe it to 'less -r'. + +*/ + +#define AFL_MAIN +#include "android-ashmem.h" + +#include "config.h" +#include "types.h" +#include "debug.h" +#include "alloc-inl.h" +#include "hash.h" + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include + +static s32 child_pid; /* PID of the tested program */ + +static u8* trace_bits; /* SHM with instrumentation bitmap */ + +static u8 *in_file, /* Analyzer input test case */ + *prog_in, /* Targeted program input file */ + *target_path, /* Path to target binary */ + *doc_path; /* Path to docs */ + +static u8 *in_data; /* Input data for analysis */ + +static u32 in_len, /* Input data length */ + orig_cksum, /* Original checksum */ + total_execs, /* Total number of execs */ + exec_hangs, /* Total number of hangs */ + exec_tmout = EXEC_TIMEOUT; /* Exec timeout (ms) */ + +static u64 mem_limit = MEM_LIMIT; /* Memory limit (MB) */ + +static s32 shm_id, /* ID of the SHM region */ + dev_null_fd = -1; /* FD to /dev/null */ + +static u8 edges_only, /* Ignore hit counts? */ + use_hex_offsets, /* Show hex offsets? */ + use_stdin = 1; /* Use stdin for program input? */ + +static volatile u8 + stop_soon, /* Ctrl-C pressed? */ + child_timed_out; /* Child timed out? */ + + +/* Constants used for describing byte behavior. */ + +#define RESP_NONE 0x00 /* Changing byte is a no-op. */ +#define RESP_MINOR 0x01 /* Some changes have no effect. */ +#define RESP_VARIABLE 0x02 /* Changes produce variable paths. */ +#define RESP_FIXED 0x03 /* Changes produce fixed patterns. */ + +#define RESP_LEN 0x04 /* Potential length field */ +#define RESP_CKSUM 0x05 /* Potential checksum */ +#define RESP_SUSPECT 0x06 /* Potential "suspect" blob */ + + +/* Classify tuple counts. This is a slow & naive version, but good enough here. */ + +static u8 count_class_lookup[256] = { + + [0] = 0, + [1] = 1, + [2] = 2, + [3] = 4, + [4 ... 7] = 8, + [8 ... 15] = 16, + [16 ... 31] = 32, + [32 ... 127] = 64, + [128 ... 255] = 128 + +}; + +static void classify_counts(u8* mem) { + + u32 i = MAP_SIZE; + + if (edges_only) { + + while (i--) { + if (*mem) *mem = 1; + mem++; + } + + } else { + + while (i--) { + *mem = count_class_lookup[*mem]; + mem++; + } + + } + +} + + +/* See if any bytes are set in the bitmap. */ + +static inline u8 anything_set(void) { + + u32* ptr = (u32*)trace_bits; + u32 i = (MAP_SIZE >> 2); + + while (i--) if (*(ptr++)) return 1; + + return 0; + +} + + +/* Get rid of shared memory and temp files (atexit handler). */ + +static void remove_shm(void) { + + unlink(prog_in); /* Ignore errors */ + shmctl(shm_id, IPC_RMID, NULL); + +} + + +/* Configure shared memory. */ + +static void setup_shm(void) { + + u8* shm_str; + + shm_id = shmget(IPC_PRIVATE, MAP_SIZE, IPC_CREAT | IPC_EXCL | 0600); + + if (shm_id < 0) PFATAL("shmget() failed"); + + atexit(remove_shm); + + shm_str = alloc_printf("%d", shm_id); + + setenv(SHM_ENV_VAR, shm_str, 1); + + ck_free(shm_str); + + trace_bits = shmat(shm_id, NULL, 0); + + if (trace_bits == (void *)-1) PFATAL("shmat() failed"); + +} + + +/* Read initial file. */ + +static void read_initial_file(void) { + + struct stat st; + s32 fd = open(in_file, O_RDONLY); + + if (fd < 0) PFATAL("Unable to open '%s'", in_file); + + if (fstat(fd, &st) || !st.st_size) + FATAL("Zero-sized input file."); + + if (st.st_size >= TMIN_MAX_FILE) + FATAL("Input file is too large (%u MB max)", TMIN_MAX_FILE / 1024 / 1024); + + in_len = st.st_size; + in_data = ck_alloc_nozero(in_len); + + ck_read(fd, in_data, in_len, in_file); + + close(fd); + + OKF("Read %u byte%s from '%s'.", in_len, in_len == 1 ? "" : "s", in_file); + +} + + +/* Write output file. */ + +static s32 write_to_file(u8* path, u8* mem, u32 len) { + + s32 ret; + + unlink(path); /* Ignore errors */ + + ret = open(path, O_RDWR | O_CREAT | O_EXCL, 0600); + + if (ret < 0) PFATAL("Unable to create '%s'", path); + + ck_write(ret, mem, len, path); + + lseek(ret, 0, SEEK_SET); + + return ret; + +} + + +/* Handle timeout signal. */ + +static void handle_timeout(int sig) { + + child_timed_out = 1; + if (child_pid > 0) kill(child_pid, SIGKILL); + +} + + +/* Execute target application. Returns exec checksum, or 0 if program + times out. */ + +static u32 run_target(char** argv, u8* mem, u32 len, u8 first_run) { + + static struct itimerval it; + int status = 0; + + s32 prog_in_fd; + u32 cksum; + + memset(trace_bits, 0, MAP_SIZE); + MEM_BARRIER(); + + prog_in_fd = write_to_file(prog_in, mem, len); + + child_pid = fork(); + + if (child_pid < 0) PFATAL("fork() failed"); + + if (!child_pid) { + + struct rlimit r; + + if (dup2(use_stdin ? prog_in_fd : dev_null_fd, 0) < 0 || + dup2(dev_null_fd, 1) < 0 || + dup2(dev_null_fd, 2) < 0) { + + *(u32*)trace_bits = EXEC_FAIL_SIG; + PFATAL("dup2() failed"); + + } + + close(dev_null_fd); + close(prog_in_fd); + + if (mem_limit) { + + r.rlim_max = r.rlim_cur = ((rlim_t)mem_limit) << 20; + +#ifdef RLIMIT_AS + + setrlimit(RLIMIT_AS, &r); /* Ignore errors */ + +#else + + setrlimit(RLIMIT_DATA, &r); /* Ignore errors */ + +#endif /* ^RLIMIT_AS */ + + } + + r.rlim_max = r.rlim_cur = 0; + setrlimit(RLIMIT_CORE, &r); /* Ignore errors */ + + execv(target_path, argv); + + *(u32*)trace_bits = EXEC_FAIL_SIG; + exit(0); + + } + + close(prog_in_fd); + + /* Configure timeout, wait for child, cancel timeout. */ + + child_timed_out = 0; + it.it_value.tv_sec = (exec_tmout / 1000); + it.it_value.tv_usec = (exec_tmout % 1000) * 1000; + + setitimer(ITIMER_REAL, &it, NULL); + + if (waitpid(child_pid, &status, 0) <= 0) FATAL("waitpid() failed"); + + child_pid = 0; + it.it_value.tv_sec = 0; + it.it_value.tv_usec = 0; + + setitimer(ITIMER_REAL, &it, NULL); + + MEM_BARRIER(); + + /* Clean up bitmap, analyze exit condition, etc. */ + + if (*(u32*)trace_bits == EXEC_FAIL_SIG) + FATAL("Unable to execute '%s'", argv[0]); + + classify_counts(trace_bits); + total_execs++; + + if (stop_soon) { + SAYF(cRST cLRD "\n+++ Analysis aborted by user +++\n" cRST); + exit(1); + } + + /* Always discard inputs that time out. */ + + if (child_timed_out) { + + exec_hangs++; + return 0; + + } + + cksum = hash32(trace_bits, MAP_SIZE, HASH_CONST); + + /* We don't actually care if the target is crashing or not, + except that when it does, the checksum should be different. */ + + if (WIFSIGNALED(status) || + (WIFEXITED(status) && WEXITSTATUS(status) == MSAN_ERROR) || + (WIFEXITED(status) && WEXITSTATUS(status))) { + + cksum ^= 0xffffffff; + + } + + if (first_run) orig_cksum = cksum; + + return cksum; + +} + + +#ifdef USE_COLOR + +/* Helper function to display a human-readable character. */ + +static void show_char(u8 val) { + + switch (val) { + + case 0 ... 32: + case 127 ... 255: SAYF("#%02x", val); break; + + default: SAYF(" %c ", val); + + } + +} + + +/* Show the legend */ + +static void show_legend(void) { + + SAYF(" " cLGR bgGRA " 01 " cRST " - no-op block " + cBLK bgLGN " 01 " cRST " - suspected length field\n" + " " cBRI bgGRA " 01 " cRST " - superficial content " + cBLK bgYEL " 01 " cRST " - suspected cksum or magic int\n" + " " cBLK bgCYA " 01 " cRST " - critical stream " + cBLK bgLRD " 01 " cRST " - suspected checksummed block\n" + " " cBLK bgMGN " 01 " cRST " - \"magic value\" section\n\n"); + +} + +#endif /* USE_COLOR */ + + +/* Interpret and report a pattern in the input file. */ + +static void dump_hex(u8* buf, u32 len, u8* b_data) { + + u32 i; + + for (i = 0; i < len; i++) { + +#ifdef USE_COLOR + u32 rlen = 1, off; +#else + u32 rlen = 1; +#endif /* ^USE_COLOR */ + + u8 rtype = b_data[i] & 0x0f; + + /* Look ahead to determine the length of run. */ + + while (i + rlen < len && (b_data[i] >> 7) == (b_data[i + rlen] >> 7)) { + + if (rtype < (b_data[i + rlen] & 0x0f)) rtype = b_data[i + rlen] & 0x0f; + rlen++; + + } + + /* Try to do some further classification based on length & value. */ + + if (rtype == RESP_FIXED) { + + switch (rlen) { + + case 2: { + + u16 val = *(u16*)(in_data + i); + + /* Small integers may be length fields. */ + + if (val && (val <= in_len || SWAP16(val) <= in_len)) { + rtype = RESP_LEN; + break; + } + + /* Uniform integers may be checksums. */ + + if (val && abs(in_data[i] - in_data[i + 1]) > 32) { + rtype = RESP_CKSUM; + break; + } + + break; + + } + + case 4: { + + u32 val = *(u32*)(in_data + i); + + /* Small integers may be length fields. */ + + if (val && (val <= in_len || SWAP32(val) <= in_len)) { + rtype = RESP_LEN; + break; + } + + /* Uniform integers may be checksums. */ + + if (val && (in_data[i] >> 7 != in_data[i + 1] >> 7 || + in_data[i] >> 7 != in_data[i + 2] >> 7 || + in_data[i] >> 7 != in_data[i + 3] >> 7)) { + rtype = RESP_CKSUM; + break; + } + + break; + + } + + case 1: case 3: case 5 ... MAX_AUTO_EXTRA - 1: break; + + default: rtype = RESP_SUSPECT; + + } + + } + + /* Print out the entire run. */ + +#ifdef USE_COLOR + + for (off = 0; off < rlen; off++) { + + /* Every 16 digits, display offset. */ + + if (!((i + off) % 16)) { + + if (off) SAYF(cRST cLCY ">"); + + if (use_hex_offsets) + SAYF(cRST cGRA "%s[%06x] " cRST, (i + off) ? "\n" : "", i + off); + else + SAYF(cRST cGRA "%s[%06u] " cRST, (i + off) ? "\n" : "", i + off); + + } + + switch (rtype) { + + case RESP_NONE: SAYF(cLGR bgGRA); break; + case RESP_MINOR: SAYF(cBRI bgGRA); break; + case RESP_VARIABLE: SAYF(cBLK bgCYA); break; + case RESP_FIXED: SAYF(cBLK bgMGN); break; + case RESP_LEN: SAYF(cBLK bgLGN); break; + case RESP_CKSUM: SAYF(cBLK bgYEL); break; + case RESP_SUSPECT: SAYF(cBLK bgLRD); break; + + } + + show_char(in_data[i + off]); + + if (off != rlen - 1 && (i + off + 1) % 16) SAYF(" "); else SAYF(cRST " "); + + } + +#else + + if (use_hex_offsets) + SAYF(" Offset %x, length %u: ", i, rlen); + else + SAYF(" Offset %u, length %u: ", i, rlen); + + switch (rtype) { + + case RESP_NONE: SAYF("no-op block\n"); break; + case RESP_MINOR: SAYF("superficial content\n"); break; + case RESP_VARIABLE: SAYF("critical stream\n"); break; + case RESP_FIXED: SAYF("\"magic value\" section\n"); break; + case RESP_LEN: SAYF("suspected length field\n"); break; + case RESP_CKSUM: SAYF("suspected cksum or magic int\n"); break; + case RESP_SUSPECT: SAYF("suspected checksummed block\n"); break; + + } + +#endif /* ^USE_COLOR */ + + i += rlen - 1; + + } + +#ifdef USE_COLOR + SAYF(cRST "\n"); +#endif /* USE_COLOR */ + +} + + + +/* Actually analyze! */ + +static void analyze(char** argv) { + + u32 i; + u32 boring_len = 0, prev_xff = 0, prev_x01 = 0, prev_s10 = 0, prev_a10 = 0; + + u8* b_data = ck_alloc(in_len + 1); + u8 seq_byte = 0; + + b_data[in_len] = 0xff; /* Intentional terminator. */ + + ACTF("Analyzing input file (this may take a while)...\n"); + +#ifdef USE_COLOR + show_legend(); +#endif /* USE_COLOR */ + + for (i = 0; i < in_len; i++) { + + u32 xor_ff, xor_01, sub_10, add_10; + u8 xff_orig, x01_orig, s10_orig, a10_orig; + + /* Perform walking byte adjustments across the file. We perform four + operations designed to elicit some response from the underlying + code. */ + + in_data[i] ^= 0xff; + xor_ff = run_target(argv, in_data, in_len, 0); + + in_data[i] ^= 0xfe; + xor_01 = run_target(argv, in_data, in_len, 0); + + in_data[i] = (in_data[i] ^ 0x01) - 0x10; + sub_10 = run_target(argv, in_data, in_len, 0); + + in_data[i] += 0x20; + add_10 = run_target(argv, in_data, in_len, 0); + in_data[i] -= 0x10; + + /* Classify current behavior. */ + + xff_orig = (xor_ff == orig_cksum); + x01_orig = (xor_01 == orig_cksum); + s10_orig = (sub_10 == orig_cksum); + a10_orig = (add_10 == orig_cksum); + + if (xff_orig && x01_orig && s10_orig && a10_orig) { + + b_data[i] = RESP_NONE; + boring_len++; + + } else if (xff_orig || x01_orig || s10_orig || a10_orig) { + + b_data[i] = RESP_MINOR; + boring_len++; + + } else if (xor_ff == xor_01 && xor_ff == sub_10 && xor_ff == add_10) { + + b_data[i] = RESP_FIXED; + + } else b_data[i] = RESP_VARIABLE; + + /* When all checksums change, flip most significant bit of b_data. */ + + if (prev_xff != xor_ff && prev_x01 != xor_01 && + prev_s10 != sub_10 && prev_a10 != add_10) seq_byte ^= 0x80; + + b_data[i] |= seq_byte; + + prev_xff = xor_ff; + prev_x01 = xor_01; + prev_s10 = sub_10; + prev_a10 = add_10; + + } + + dump_hex(in_data, in_len, b_data); + + SAYF("\n"); + + OKF("Analysis complete. Interesting bits: %0.02f%% of the input file.", + 100.0 - ((double)boring_len * 100) / in_len); + + if (exec_hangs) + WARNF(cLRD "Encountered %u timeouts - results may be skewed." cRST, + exec_hangs); + + ck_free(b_data); + +} + + + +/* Handle Ctrl-C and the like. */ + +static void handle_stop_sig(int sig) { + + stop_soon = 1; + + if (child_pid > 0) kill(child_pid, SIGKILL); + +} + + +/* Do basic preparations - persistent fds, filenames, etc. */ + +static void set_up_environment(void) { + + u8* x; + + dev_null_fd = open("/dev/null", O_RDWR); + if (dev_null_fd < 0) PFATAL("Unable to open /dev/null"); + + if (!prog_in) { + + u8* use_dir = "."; + + if (access(use_dir, R_OK | W_OK | X_OK)) { + + use_dir = getenv("TMPDIR"); + if (!use_dir) use_dir = "/tmp"; + + } + + prog_in = alloc_printf("%s/.afl-analyze-temp-%u", use_dir, getpid()); + + } + + /* Set sane defaults... */ + + x = getenv("ASAN_OPTIONS"); + + if (x) { + + if (!strstr(x, "abort_on_error=1")) + FATAL("Custom ASAN_OPTIONS set without abort_on_error=1 - please fix!"); + + if (!strstr(x, "symbolize=0")) + FATAL("Custom ASAN_OPTIONS set without symbolize=0 - please fix!"); + + } + + x = getenv("MSAN_OPTIONS"); + + if (x) { + + if (!strstr(x, "exit_code=" STRINGIFY(MSAN_ERROR))) + FATAL("Custom MSAN_OPTIONS set without exit_code=" + STRINGIFY(MSAN_ERROR) " - please fix!"); + + if (!strstr(x, "symbolize=0")) + FATAL("Custom MSAN_OPTIONS set without symbolize=0 - please fix!"); + + } + + setenv("ASAN_OPTIONS", "abort_on_error=1:" + "detect_leaks=0:" + "symbolize=0:" + "allocator_may_return_null=1", 0); + + setenv("MSAN_OPTIONS", "exit_code=" STRINGIFY(MSAN_ERROR) ":" + "symbolize=0:" + "abort_on_error=1:" + "allocator_may_return_null=1:" + "msan_track_origins=0", 0); + + if (getenv("AFL_PRELOAD")) { + setenv("LD_PRELOAD", getenv("AFL_PRELOAD"), 1); + setenv("DYLD_INSERT_LIBRARIES", getenv("AFL_PRELOAD"), 1); + } + +} + + +/* Setup signal handlers, duh. */ + +static void setup_signal_handlers(void) { + + struct sigaction sa; + + sa.sa_handler = NULL; + sa.sa_flags = SA_RESTART; + sa.sa_sigaction = NULL; + + sigemptyset(&sa.sa_mask); + + /* Various ways of saying "stop". */ + + sa.sa_handler = handle_stop_sig; + sigaction(SIGHUP, &sa, NULL); + sigaction(SIGINT, &sa, NULL); + sigaction(SIGTERM, &sa, NULL); + + /* Exec timeout notifications. */ + + sa.sa_handler = handle_timeout; + sigaction(SIGALRM, &sa, NULL); + +} + + +/* Detect @@ in args. */ + +static void detect_file_args(char** argv) { + + u32 i = 0; + u8* cwd = getcwd(NULL, 0); + + if (!cwd) PFATAL("getcwd() failed"); + + while (argv[i]) { + + u8* aa_loc = strstr(argv[i], "@@"); + + if (aa_loc) { + + u8 *aa_subst, *n_arg; + + /* Be sure that we're always using fully-qualified paths. */ + + if (prog_in[0] == '/') aa_subst = prog_in; + else aa_subst = alloc_printf("%s/%s", cwd, prog_in); + + /* Construct a replacement argv value. */ + + *aa_loc = 0; + n_arg = alloc_printf("%s%s%s", argv[i], aa_subst, aa_loc + 2); + argv[i] = n_arg; + *aa_loc = '@'; + + if (prog_in[0] != '/') ck_free(aa_subst); + + } + + i++; + + } + + free(cwd); /* not tracked */ + +} + + +/* Display usage hints. */ + +static void usage(u8* argv0) { + + SAYF("\n%s [ options ] -- /path/to/target_app [ ... ]\n\n" + + "Required parameters:\n\n" + + " -i file - input test case to be analyzed by the tool\n" + + "Execution control settings:\n\n" + + " -f file - input file read by the tested program (stdin)\n" + " -t msec - timeout for each run (%u ms)\n" + " -m megs - memory limit for child process (%u MB)\n" + " -Q - use binary-only instrumentation (QEMU mode)\n\n" + + "Analysis settings:\n\n" + + " -e - look for edge coverage only, ignore hit counts\n\n" + + "Other stuff:\n\n" + + " -V - show version number and exit\n\n" + + "For additional tips, please consult %s/README.\n\n", + + argv0, EXEC_TIMEOUT, MEM_LIMIT, doc_path); + + exit(1); + +} + + +/* Find binary. */ + +static void find_binary(u8* fname) { + + u8* env_path = 0; + struct stat st; + + if (strchr(fname, '/') || !(env_path = getenv("PATH"))) { + + target_path = ck_strdup(fname); + + if (stat(target_path, &st) || !S_ISREG(st.st_mode) || + !(st.st_mode & 0111) || st.st_size < 4) + FATAL("Program '%s' not found or not executable", fname); + + } else { + + while (env_path) { + + u8 *cur_elem, *delim = strchr(env_path, ':'); + + if (delim) { + + cur_elem = ck_alloc(delim - env_path + 1); + memcpy(cur_elem, env_path, delim - env_path); + delim++; + + } else cur_elem = ck_strdup(env_path); + + env_path = delim; + + if (cur_elem[0]) + target_path = alloc_printf("%s/%s", cur_elem, fname); + else + target_path = ck_strdup(fname); + + ck_free(cur_elem); + + if (!stat(target_path, &st) && S_ISREG(st.st_mode) && + (st.st_mode & 0111) && st.st_size >= 4) break; + + ck_free(target_path); + target_path = 0; + + } + + if (!target_path) FATAL("Program '%s' not found or not executable", fname); + + } + +} + + +/* Fix up argv for QEMU. */ + +static char** get_qemu_argv(u8* own_loc, char** argv, int argc) { + + char** new_argv = ck_alloc(sizeof(char*) * (argc + 4)); + u8 *tmp, *cp, *rsl, *own_copy; + + /* Workaround for a QEMU stability glitch. */ + + setenv("QEMU_LOG", "nochain", 1); + + memcpy(new_argv + 3, argv + 1, sizeof(char*) * argc); + + /* Now we need to actually find qemu for argv[0]. */ + + new_argv[2] = target_path; + new_argv[1] = "--"; + + tmp = getenv("AFL_PATH"); + + if (tmp) { + + cp = alloc_printf("%s/afl-qemu-trace", tmp); + + if (access(cp, X_OK)) + FATAL("Unable to find '%s'", tmp); + + target_path = new_argv[0] = cp; + return new_argv; + + } + + own_copy = ck_strdup(own_loc); + rsl = strrchr(own_copy, '/'); + + if (rsl) { + + *rsl = 0; + + cp = alloc_printf("%s/afl-qemu-trace", own_copy); + ck_free(own_copy); + + if (!access(cp, X_OK)) { + + target_path = new_argv[0] = cp; + return new_argv; + + } + + } else ck_free(own_copy); + + if (!access(BIN_PATH "/afl-qemu-trace", X_OK)) { + + target_path = new_argv[0] = BIN_PATH "/afl-qemu-trace"; + return new_argv; + + } + + FATAL("Unable to find 'afl-qemu-trace'."); + +} + + +/* Main entry point */ + +int main(int argc, char** argv) { + + s32 opt; + u8 mem_limit_given = 0, timeout_given = 0, qemu_mode = 0; + char** use_argv; + + doc_path = access(DOC_PATH, F_OK) ? "docs" : DOC_PATH; + + SAYF(cCYA "afl-analyze " cBRI VERSION cRST " by \n"); + + while ((opt = getopt(argc,argv,"+i:f:m:t:eQV")) > 0) + + switch (opt) { + + case 'i': + + if (in_file) FATAL("Multiple -i options not supported"); + in_file = optarg; + break; + + case 'f': + + if (prog_in) FATAL("Multiple -f options not supported"); + use_stdin = 0; + prog_in = optarg; + break; + + case 'e': + + if (edges_only) FATAL("Multiple -e options not supported"); + edges_only = 1; + break; + + case 'm': { + + u8 suffix = 'M'; + + if (mem_limit_given) FATAL("Multiple -m options not supported"); + mem_limit_given = 1; + + if (!strcmp(optarg, "none")) { + + mem_limit = 0; + break; + + } + + if (sscanf(optarg, "%llu%c", &mem_limit, &suffix) < 1 || + optarg[0] == '-') FATAL("Bad syntax used for -m"); + + switch (suffix) { + + case 'T': mem_limit *= 1024 * 1024; break; + case 'G': mem_limit *= 1024; break; + case 'k': mem_limit /= 1024; break; + case 'M': break; + + default: FATAL("Unsupported suffix or bad syntax for -m"); + + } + + if (mem_limit < 5) FATAL("Dangerously low value of -m"); + + if (sizeof(rlim_t) == 4 && mem_limit > 2000) + FATAL("Value of -m out of range on 32-bit systems"); + + } + + break; + + case 't': + + if (timeout_given) FATAL("Multiple -t options not supported"); + timeout_given = 1; + + exec_tmout = atoi(optarg); + + if (exec_tmout < 10 || optarg[0] == '-') + FATAL("Dangerously low value of -t"); + + break; + + case 'Q': + + if (qemu_mode) FATAL("Multiple -Q options not supported"); + if (!mem_limit_given) mem_limit = MEM_LIMIT_QEMU; + + qemu_mode = 1; + break; + + case 'V': /* Show version number */ + + /* Version number has been printed already, just quit. */ + exit(0); + + default: + + usage(argv[0]); + + } + + if (optind == argc || !in_file) usage(argv[0]); + + use_hex_offsets = !!getenv("AFL_ANALYZE_HEX"); + + setup_shm(); + setup_signal_handlers(); + + set_up_environment(); + + find_binary(argv[optind]); + detect_file_args(argv + optind); + + if (qemu_mode) + use_argv = get_qemu_argv(argv[0], argv + optind, argc - optind); + else + use_argv = argv + optind; + + SAYF("\n"); + + read_initial_file(); + + ACTF("Performing dry run (mem limit = %llu MB, timeout = %u ms%s)...", + mem_limit, exec_tmout, edges_only ? ", edges only" : ""); + + run_target(use_argv, in_data, in_len, 1); + + if (child_timed_out) + FATAL("Target binary times out (adjusting -t may help)."); + + if (!anything_set()) FATAL("No instrumentation detected."); + + analyze(use_argv); + + OKF("We're done here. Have a nice day!\n"); + + exit(0); + +} + diff --git a/src/afl-as.c b/src/afl-as.c new file mode 100644 index 0000000..ea018ee --- /dev/null +++ b/src/afl-as.c @@ -0,0 +1,557 @@ +/* + Copyright 2013 Google LLC All rights reserved. + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at: + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +*/ + +/* + american fuzzy lop - wrapper for GNU as + --------------------------------------- + + Written and maintained by Michal Zalewski + + The sole purpose of this wrapper is to preprocess assembly files generated + by GCC / clang and inject the instrumentation bits included from afl-as.h. It + is automatically invoked by the toolchain when compiling programs using + afl-gcc / afl-clang. + + Note that it's an explicit non-goal to instrument hand-written assembly, + be it in separate .s files or in __asm__ blocks. The only aspiration this + utility has right now is to be able to skip them gracefully and allow the + compilation process to continue. + + That said, see experimental/clang_asm_normalize/ for a solution that may + allow clang users to make things work even with hand-crafted assembly. Just + note that there is no equivalent for GCC. + +*/ + +#define AFL_MAIN + +#include "config.h" +#include "types.h" +#include "debug.h" +#include "alloc-inl.h" + +#include "afl-as.h" + +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +static u8** as_params; /* Parameters passed to the real 'as' */ + +static u8* input_file; /* Originally specified input file */ +static u8* modified_file; /* Instrumented file for the real 'as' */ + +static u8 be_quiet, /* Quiet mode (no stderr output) */ + clang_mode, /* Running in clang mode? */ + pass_thru, /* Just pass data through? */ + just_version, /* Just show version? */ + sanitizer; /* Using ASAN / MSAN */ + +static u32 inst_ratio = 100, /* Instrumentation probability (%) */ + as_par_cnt = 1; /* Number of params to 'as' */ + +/* If we don't find --32 or --64 in the command line, default to + instrumentation for whichever mode we were compiled with. This is not + perfect, but should do the trick for almost all use cases. */ + +#ifdef WORD_SIZE_64 + +static u8 use_64bit = 1; + +#else + +static u8 use_64bit = 0; + +#ifdef __APPLE__ +# error "Sorry, 32-bit Apple platforms are not supported." +#endif /* __APPLE__ */ + +#endif /* ^WORD_SIZE_64 */ + + +/* Examine and modify parameters to pass to 'as'. Note that the file name + is always the last parameter passed by GCC, so we exploit this property + to keep the code simple. */ + +static void edit_params(int argc, char** argv) { + + u8 *tmp_dir = getenv("TMPDIR"), *afl_as = getenv("AFL_AS"); + u32 i; + +#ifdef __APPLE__ + + u8 use_clang_as = 0; + + /* On MacOS X, the Xcode cctool 'as' driver is a bit stale and does not work + with the code generated by newer versions of clang that are hand-built + by the user. See the thread here: http://goo.gl/HBWDtn. + + To work around this, when using clang and running without AFL_AS + specified, we will actually call 'clang -c' instead of 'as -q' to + compile the assembly file. + + The tools aren't cmdline-compatible, but at least for now, we can + seemingly get away with this by making only very minor tweaks. Thanks + to Nico Weber for the idea. */ + + if (clang_mode && !afl_as) { + + use_clang_as = 1; + + afl_as = getenv("AFL_CC"); + if (!afl_as) afl_as = getenv("AFL_CXX"); + if (!afl_as) afl_as = "clang"; + + } + +#endif /* __APPLE__ */ + + /* Although this is not documented, GCC also uses TEMP and TMP when TMPDIR + is not set. We need to check these non-standard variables to properly + handle the pass_thru logic later on. */ + + if (!tmp_dir) tmp_dir = getenv("TEMP"); + if (!tmp_dir) tmp_dir = getenv("TMP"); + if (!tmp_dir) tmp_dir = "/tmp"; + + as_params = ck_alloc((argc + 32) * sizeof(u8*)); + + as_params[0] = afl_as ? afl_as : (u8*)"as"; + + as_params[argc] = 0; + + for (i = 1; i < argc - 1; i++) { + + if (!strcmp(argv[i], "--64")) use_64bit = 1; + else if (!strcmp(argv[i], "--32")) use_64bit = 0; + +#ifdef __APPLE__ + + /* The Apple case is a bit different... */ + + if (!strcmp(argv[i], "-arch") && i + 1 < argc) { + + if (!strcmp(argv[i + 1], "x86_64")) use_64bit = 1; + else if (!strcmp(argv[i + 1], "i386")) + FATAL("Sorry, 32-bit Apple platforms are not supported."); + + } + + /* Strip options that set the preference for a particular upstream + assembler in Xcode. */ + + if (clang_mode && (!strcmp(argv[i], "-q") || !strcmp(argv[i], "-Q"))) + continue; + +#endif /* __APPLE__ */ + + as_params[as_par_cnt++] = argv[i]; + + } + +#ifdef __APPLE__ + + /* When calling clang as the upstream assembler, append -c -x assembler + and hope for the best. */ + + if (use_clang_as) { + + as_params[as_par_cnt++] = "-c"; + as_params[as_par_cnt++] = "-x"; + as_params[as_par_cnt++] = "assembler"; + + } + +#endif /* __APPLE__ */ + + input_file = argv[argc - 1]; + + if (input_file[0] == '-') { + + if (!strcmp(input_file + 1, "-version")) { + just_version = 1; + modified_file = input_file; + goto wrap_things_up; + } + + if (input_file[1]) FATAL("Incorrect use (not called through afl-gcc?)"); + else input_file = NULL; + + } else { + + /* Check if this looks like a standard invocation as a part of an attempt + to compile a program, rather than using gcc on an ad-hoc .s file in + a format we may not understand. This works around an issue compiling + NSS. */ + + if (strncmp(input_file, tmp_dir, strlen(tmp_dir)) && + strncmp(input_file, "/var/tmp/", 9) && + strncmp(input_file, "/tmp/", 5)) pass_thru = 1; + + } + + modified_file = alloc_printf("%s/.afl-%u-%u.s", tmp_dir, getpid(), + (u32)time(NULL)); + +wrap_things_up: + + as_params[as_par_cnt++] = modified_file; + as_params[as_par_cnt] = NULL; + +} + + +/* Process input file, generate modified_file. Insert instrumentation in all + the appropriate places. */ + +static void add_instrumentation(void) { + + static u8 line[MAX_LINE]; + + FILE* inf; + FILE* outf; + s32 outfd; + u32 ins_lines = 0; + + u8 instr_ok = 0, skip_csect = 0, skip_next_label = 0, + skip_intel = 0, skip_app = 0, instrument_next = 0; + +#ifdef __APPLE__ + + u8* colon_pos; + +#endif /* __APPLE__ */ + + if (input_file) { + + inf = fopen(input_file, "r"); + if (!inf) PFATAL("Unable to read '%s'", input_file); + + } else inf = stdin; + + outfd = open(modified_file, O_WRONLY | O_EXCL | O_CREAT, 0600); + + if (outfd < 0) PFATAL("Unable to write to '%s'", modified_file); + + outf = fdopen(outfd, "w"); + + if (!outf) PFATAL("fdopen() failed"); + + while (fgets(line, MAX_LINE, inf)) { + + /* In some cases, we want to defer writing the instrumentation trampoline + until after all the labels, macros, comments, etc. If we're in this + mode, and if the line starts with a tab followed by a character, dump + the trampoline now. */ + + if (!pass_thru && !skip_intel && !skip_app && !skip_csect && instr_ok && + instrument_next && line[0] == '\t' && isalpha(line[1])) { + + fprintf(outf, use_64bit ? trampoline_fmt_64 : trampoline_fmt_32, + R(MAP_SIZE)); + + instrument_next = 0; + ins_lines++; + + } + + /* Output the actual line, call it a day in pass-thru mode. */ + + fputs(line, outf); + + if (pass_thru) continue; + + /* All right, this is where the actual fun begins. For one, we only want to + instrument the .text section. So, let's keep track of that in processed + files - and let's set instr_ok accordingly. */ + + if (line[0] == '\t' && line[1] == '.') { + + /* OpenBSD puts jump tables directly inline with the code, which is + a bit annoying. They use a specific format of p2align directives + around them, so we use that as a signal. */ + + if (!clang_mode && instr_ok && !strncmp(line + 2, "p2align ", 8) && + isdigit(line[10]) && line[11] == '\n') skip_next_label = 1; + + if (!strncmp(line + 2, "text\n", 5) || + !strncmp(line + 2, "section\t.text", 13) || + !strncmp(line + 2, "section\t__TEXT,__text", 21) || + !strncmp(line + 2, "section __TEXT,__text", 21)) { + instr_ok = 1; + continue; + } + + if (!strncmp(line + 2, "section\t", 8) || + !strncmp(line + 2, "section ", 8) || + !strncmp(line + 2, "bss\n", 4) || + !strncmp(line + 2, "data\n", 5)) { + instr_ok = 0; + continue; + } + + } + + /* Detect off-flavor assembly (rare, happens in gdb). When this is + encountered, we set skip_csect until the opposite directive is + seen, and we do not instrument. */ + + if (strstr(line, ".code")) { + + if (strstr(line, ".code32")) skip_csect = use_64bit; + if (strstr(line, ".code64")) skip_csect = !use_64bit; + + } + + /* Detect syntax changes, as could happen with hand-written assembly. + Skip Intel blocks, resume instrumentation when back to AT&T. */ + + if (strstr(line, ".intel_syntax")) skip_intel = 1; + if (strstr(line, ".att_syntax")) skip_intel = 0; + + /* Detect and skip ad-hoc __asm__ blocks, likewise skipping them. */ + + if (line[0] == '#' || line[1] == '#') { + + if (strstr(line, "#APP")) skip_app = 1; + if (strstr(line, "#NO_APP")) skip_app = 0; + + } + + /* If we're in the right mood for instrumenting, check for function + names or conditional labels. This is a bit messy, but in essence, + we want to catch: + + ^main: - function entry point (always instrumented) + ^.L0: - GCC branch label + ^.LBB0_0: - clang branch label (but only in clang mode) + ^\tjnz foo - conditional branches + + ...but not: + + ^# BB#0: - clang comments + ^ # BB#0: - ditto + ^.Ltmp0: - clang non-branch labels + ^.LC0 - GCC non-branch labels + ^.LBB0_0: - ditto (when in GCC mode) + ^\tjmp foo - non-conditional jumps + + Additionally, clang and GCC on MacOS X follow a different convention + with no leading dots on labels, hence the weird maze of #ifdefs + later on. + + */ + + if (skip_intel || skip_app || skip_csect || !instr_ok || + line[0] == '#' || line[0] == ' ') continue; + + /* Conditional branch instruction (jnz, etc). We append the instrumentation + right after the branch (to instrument the not-taken path) and at the + branch destination label (handled later on). */ + + if (line[0] == '\t') { + + if (line[1] == 'j' && line[2] != 'm' && R(100) < inst_ratio) { + + fprintf(outf, use_64bit ? trampoline_fmt_64 : trampoline_fmt_32, + R(MAP_SIZE)); + + ins_lines++; + + } + + continue; + + } + + /* Label of some sort. This may be a branch destination, but we need to + tread carefully and account for several different formatting + conventions. */ + +#ifdef __APPLE__ + + /* Apple: L: */ + + if ((colon_pos = strstr(line, ":"))) { + + if (line[0] == 'L' && isdigit(*(colon_pos - 1))) { + +#else + + /* Everybody else: .L: */ + + if (strstr(line, ":")) { + + if (line[0] == '.') { + +#endif /* __APPLE__ */ + + /* .L0: or LBB0_0: style jump destination */ + +#ifdef __APPLE__ + + /* Apple: L / LBB */ + + if ((isdigit(line[1]) || (clang_mode && !strncmp(line, "LBB", 3))) + && R(100) < inst_ratio) { + +#else + + /* Apple: .L / .LBB */ + + if ((isdigit(line[2]) || (clang_mode && !strncmp(line + 1, "LBB", 3))) + && R(100) < inst_ratio) { + +#endif /* __APPLE__ */ + + /* An optimization is possible here by adding the code only if the + label is mentioned in the code in contexts other than call / jmp. + That said, this complicates the code by requiring two-pass + processing (messy with stdin), and results in a speed gain + typically under 10%, because compilers are generally pretty good + about not generating spurious intra-function jumps. + + We use deferred output chiefly to avoid disrupting + .Lfunc_begin0-style exception handling calculations (a problem on + MacOS X). */ + + if (!skip_next_label) instrument_next = 1; else skip_next_label = 0; + + } + + } else { + + /* Function label (always instrumented, deferred mode). */ + + instrument_next = 1; + + } + + } + + } + + if (ins_lines) + fputs(use_64bit ? main_payload_64 : main_payload_32, outf); + + if (input_file) fclose(inf); + fclose(outf); + + if (!be_quiet) { + + if (!ins_lines) WARNF("No instrumentation targets found%s.", + pass_thru ? " (pass-thru mode)" : ""); + else OKF("Instrumented %u locations (%s-bit, %s mode, ratio %u%%).", + ins_lines, use_64bit ? "64" : "32", + getenv("AFL_HARDEN") ? "hardened" : + (sanitizer ? "ASAN/MSAN" : "non-hardened"), + inst_ratio); + + } + +} + + +/* Main entry point */ + +int main(int argc, char** argv) { + + s32 pid; + u32 rand_seed; + int status; + u8* inst_ratio_str = getenv("AFL_INST_RATIO"); + + struct timeval tv; + struct timezone tz; + + clang_mode = !!getenv(CLANG_ENV_VAR); + + if (isatty(2) && !getenv("AFL_QUIET")) { + + SAYF(cCYA "afl-as " cBRI VERSION cRST " by \n"); + + } else be_quiet = 1; + + if (argc < 2) { + + SAYF("\n" + "This is a helper application for afl-fuzz. It is a wrapper around GNU 'as',\n" + "executed by the toolchain whenever using afl-gcc or afl-clang. You probably\n" + "don't want to run this program directly.\n\n" + + "Rarely, when dealing with extremely complex projects, it may be advisable to\n" + "set AFL_INST_RATIO to a value less than 100 in order to reduce the odds of\n" + "instrumenting every discovered branch.\n\n"); + + exit(1); + + } + + gettimeofday(&tv, &tz); + + rand_seed = tv.tv_sec ^ tv.tv_usec ^ getpid(); + + srandom(rand_seed); + + edit_params(argc, argv); + + if (inst_ratio_str) { + + if (sscanf(inst_ratio_str, "%u", &inst_ratio) != 1 || inst_ratio > 100) + FATAL("Bad value of AFL_INST_RATIO (must be between 0 and 100)"); + + } + + if (getenv(AS_LOOP_ENV_VAR)) + FATAL("Endless loop when calling 'as' (remove '.' from your PATH)"); + + setenv(AS_LOOP_ENV_VAR, "1", 1); + + /* When compiling with ASAN, we don't have a particularly elegant way to skip + ASAN-specific branches. But we can probabilistically compensate for + that... */ + + if (getenv("AFL_USE_ASAN") || getenv("AFL_USE_MSAN")) { + sanitizer = 1; + inst_ratio /= 3; + } + + if (!just_version) add_instrumentation(); + + if (!(pid = fork())) { + + execvp(as_params[0], (char**)as_params); + FATAL("Oops, failed to execute '%s' - check your PATH", as_params[0]); + + } + + if (pid < 0) PFATAL("fork() failed"); + + if (waitpid(pid, &status, 0) <= 0) PFATAL("waitpid() failed"); + + if (!getenv("AFL_KEEP_ASSEMBLY")) unlink(modified_file); + + exit(WEXITSTATUS(status)); + +} + diff --git a/src/afl-as.h b/src/afl-as.h new file mode 100644 index 0000000..276b8a4 --- /dev/null +++ b/src/afl-as.h @@ -0,0 +1,727 @@ +/* + Copyright 2013 Google LLC All rights reserved. + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at: + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +*/ + +/* + american fuzzy lop - injectable parts + ------------------------------------- + + Written and maintained by Michal Zalewski + + Forkserver design by Jann Horn + + This file houses the assembly-level instrumentation injected into fuzzed + programs. The instrumentation stores XORed pairs of data: identifiers of the + currently executing branch and the one that executed immediately before. + + TL;DR: the instrumentation does shm_trace_map[cur_loc ^ prev_loc]++ + + The code is designed for 32-bit and 64-bit x86 systems. Both modes should + work everywhere except for Apple systems. Apple does relocations differently + from everybody else, so since their OSes have been 64-bit for a longer while, + I didn't go through the mental effort of porting the 32-bit code. + + In principle, similar code should be easy to inject into any well-behaved + binary-only code (e.g., using DynamoRIO). Conditional jumps offer natural + targets for instrumentation, and should offer comparable probe density. + +*/ + +#ifndef _HAVE_AFL_AS_H +#define _HAVE_AFL_AS_H + +#include "config.h" +#include "types.h" + +/* + ------------------ + Performances notes + ------------------ + + Contributions to make this code faster are appreciated! Here are some + rough notes that may help with the task: + + - Only the trampoline_fmt and the non-setup __afl_maybe_log code paths are + really worth optimizing; the setup / fork server stuff matters a lot less + and should be mostly just kept readable. + + - We're aiming for modern CPUs with out-of-order execution and large + pipelines; the code is mostly follows intuitive, human-readable + instruction ordering, because "textbook" manual reorderings make no + substantial difference. + + - Interestingly, instrumented execution isn't a lot faster if we store a + variable pointer to the setup, log, or return routine and then do a reg + call from within trampoline_fmt. It does speed up non-instrumented + execution quite a bit, though, since that path just becomes + push-call-ret-pop. + + - There is also not a whole lot to be gained by doing SHM attach at a + fixed address instead of retrieving __afl_area_ptr. Although it allows us + to have a shorter log routine inserted for conditional jumps and jump + labels (for a ~10% perf gain), there is a risk of bumping into other + allocations created by the program or by tools such as ASAN. + + - popf is *awfully* slow, which is why we're doing the lahf / sahf + + overflow test trick. Unfortunately, this forces us to taint eax / rax, but + this dependency on a commonly-used register still beats the alternative of + using pushf / popf. + + One possible optimization is to avoid touching flags by using a circular + buffer that stores just a sequence of current locations, with the XOR stuff + happening offline. Alas, this doesn't seem to have a huge impact: + + https://groups.google.com/d/msg/afl-users/MsajVf4fRLo/2u6t88ntUBIJ + + - Preforking one child a bit sooner, and then waiting for the "go" command + from within the child, doesn't offer major performance gains; fork() seems + to be relatively inexpensive these days. Preforking multiple children does + help, but badly breaks the "~1 core per fuzzer" design, making it harder to + scale up. Maybe there is some middle ground. + + Perhaps of note: in the 64-bit version for all platforms except for Apple, + the instrumentation is done slightly differently than on 32-bit, with + __afl_prev_loc and __afl_area_ptr being local to the object file (.lcomm), + rather than global (.comm). This is to avoid GOTRELPC lookups in the critical + code path, which AFAICT, are otherwise unavoidable if we want gcc -shared to + work; simple relocations between .bss and .text won't work on most 64-bit + platforms in such a case. + + (Fun fact: on Apple systems, .lcomm can segfault the linker.) + + The side effect is that state transitions are measured in a somewhat + different way, with previous tuple being recorded separately within the scope + of every .c file. This should have no impact in any practical sense. + + Another side effect of this design is that getenv() will be called once per + every .o file when running in non-instrumented mode; and since getenv() tends + to be optimized in funny ways, we need to be very careful to save every + oddball register it may touch. + + */ + +static const u8* trampoline_fmt_32 = + + "\n" + "/* --- AFL TRAMPOLINE (32-BIT) --- */\n" + "\n" + ".align 4\n" + "\n" + "leal -16(%%esp), %%esp\n" + "movl %%edi, 0(%%esp)\n" + "movl %%edx, 4(%%esp)\n" + "movl %%ecx, 8(%%esp)\n" + "movl %%eax, 12(%%esp)\n" + "movl $0x%08x, %%ecx\n" + "call __afl_maybe_log\n" + "movl 12(%%esp), %%eax\n" + "movl 8(%%esp), %%ecx\n" + "movl 4(%%esp), %%edx\n" + "movl 0(%%esp), %%edi\n" + "leal 16(%%esp), %%esp\n" + "\n" + "/* --- END --- */\n" + "\n"; + +static const u8* trampoline_fmt_64 = + + "\n" + "/* --- AFL TRAMPOLINE (64-BIT) --- */\n" + "\n" + ".align 4\n" + "\n" + "leaq -(128+24)(%%rsp), %%rsp\n" + "movq %%rdx, 0(%%rsp)\n" + "movq %%rcx, 8(%%rsp)\n" + "movq %%rax, 16(%%rsp)\n" + "movq $0x%08x, %%rcx\n" + "call __afl_maybe_log\n" + "movq 16(%%rsp), %%rax\n" + "movq 8(%%rsp), %%rcx\n" + "movq 0(%%rsp), %%rdx\n" + "leaq (128+24)(%%rsp), %%rsp\n" + "\n" + "/* --- END --- */\n" + "\n"; + +static const u8* main_payload_32 = + + "\n" + "/* --- AFL MAIN PAYLOAD (32-BIT) --- */\n" + "\n" + ".text\n" + ".att_syntax\n" + ".code32\n" + ".align 8\n" + "\n" + + "__afl_maybe_log:\n" + "\n" + " lahf\n" + " seto %al\n" + "\n" + " /* Check if SHM region is already mapped. */\n" + "\n" + " movl __afl_area_ptr, %edx\n" + " testl %edx, %edx\n" + " je __afl_setup\n" + "\n" + "__afl_store:\n" + "\n" + " /* Calculate and store hit for the code location specified in ecx. There\n" + " is a double-XOR way of doing this without tainting another register,\n" + " and we use it on 64-bit systems; but it's slower for 32-bit ones. */\n" + "\n" +#ifndef COVERAGE_ONLY + " movl __afl_prev_loc, %edi\n" + " xorl %ecx, %edi\n" + " shrl $1, %ecx\n" + " movl %ecx, __afl_prev_loc\n" +#else + " movl %ecx, %edi\n" +#endif /* ^!COVERAGE_ONLY */ + "\n" +#ifdef SKIP_COUNTS + " orb $1, (%edx, %edi, 1)\n" +#else + " incb (%edx, %edi, 1)\n" +#endif /* ^SKIP_COUNTS */ + "\n" + "__afl_return:\n" + "\n" + " addb $127, %al\n" + " sahf\n" + " ret\n" + "\n" + ".align 8\n" + "\n" + "__afl_setup:\n" + "\n" + " /* Do not retry setup if we had previous failures. */\n" + "\n" + " cmpb $0, __afl_setup_failure\n" + " jne __afl_return\n" + "\n" + " /* Map SHM, jumping to __afl_setup_abort if something goes wrong.\n" + " We do not save FPU/MMX/SSE registers here, but hopefully, nobody\n" + " will notice this early in the game. */\n" + "\n" + " pushl %eax\n" + " pushl %ecx\n" + "\n" + " pushl $.AFL_SHM_ENV\n" + " call getenv\n" + " addl $4, %esp\n" + "\n" + " testl %eax, %eax\n" + " je __afl_setup_abort\n" + "\n" + " pushl %eax\n" + " call atoi\n" + " addl $4, %esp\n" + "\n" + " pushl $0 /* shmat flags */\n" + " pushl $0 /* requested addr */\n" + " pushl %eax /* SHM ID */\n" + " call shmat\n" + " addl $12, %esp\n" + "\n" + " cmpl $-1, %eax\n" + " je __afl_setup_abort\n" + "\n" + " /* Store the address of the SHM region. */\n" + "\n" + " movl %eax, __afl_area_ptr\n" + " movl %eax, %edx\n" + "\n" + " popl %ecx\n" + " popl %eax\n" + "\n" + "__afl_forkserver:\n" + "\n" + " /* Enter the fork server mode to avoid the overhead of execve() calls. */\n" + "\n" + " pushl %eax\n" + " pushl %ecx\n" + " pushl %edx\n" + "\n" + " /* Phone home and tell the parent that we're OK. (Note that signals with\n" + " no SA_RESTART will mess it up). If this fails, assume that the fd is\n" + " closed because we were execve()d from an instrumented binary, or because\n" + " the parent doesn't want to use the fork server. */\n" + "\n" + " pushl $4 /* length */\n" + " pushl $__afl_temp /* data */\n" + " pushl $" STRINGIFY((FORKSRV_FD + 1)) " /* file desc */\n" + " call write\n" + " addl $12, %esp\n" + "\n" + " cmpl $4, %eax\n" + " jne __afl_fork_resume\n" + "\n" + "__afl_fork_wait_loop:\n" + "\n" + " /* Wait for parent by reading from the pipe. Abort if read fails. */\n" + "\n" + " pushl $4 /* length */\n" + " pushl $__afl_temp /* data */\n" + " pushl $" STRINGIFY(FORKSRV_FD) " /* file desc */\n" + " call read\n" + " addl $12, %esp\n" + "\n" + " cmpl $4, %eax\n" + " jne __afl_die\n" + "\n" + " /* Once woken up, create a clone of our process. This is an excellent use\n" + " case for syscall(__NR_clone, 0, CLONE_PARENT), but glibc boneheadedly\n" + " caches getpid() results and offers no way to update the value, breaking\n" + " abort(), raise(), and a bunch of other things :-( */\n" + "\n" + " call fork\n" + "\n" + " cmpl $0, %eax\n" + " jl __afl_die\n" + " je __afl_fork_resume\n" + "\n" + " /* In parent process: write PID to pipe, then wait for child. */\n" + "\n" + " movl %eax, __afl_fork_pid\n" + "\n" + " pushl $4 /* length */\n" + " pushl $__afl_fork_pid /* data */\n" + " pushl $" STRINGIFY((FORKSRV_FD + 1)) " /* file desc */\n" + " call write\n" + " addl $12, %esp\n" + "\n" + " pushl $0 /* no flags */\n" + " pushl $__afl_temp /* status */\n" + " pushl __afl_fork_pid /* PID */\n" + " call waitpid\n" + " addl $12, %esp\n" + "\n" + " cmpl $0, %eax\n" + " jle __afl_die\n" + "\n" + " /* Relay wait status to pipe, then loop back. */\n" + "\n" + " pushl $4 /* length */\n" + " pushl $__afl_temp /* data */\n" + " pushl $" STRINGIFY((FORKSRV_FD + 1)) " /* file desc */\n" + " call write\n" + " addl $12, %esp\n" + "\n" + " jmp __afl_fork_wait_loop\n" + "\n" + "__afl_fork_resume:\n" + "\n" + " /* In child process: close fds, resume execution. */\n" + "\n" + " pushl $" STRINGIFY(FORKSRV_FD) "\n" + " call close\n" + "\n" + " pushl $" STRINGIFY((FORKSRV_FD + 1)) "\n" + " call close\n" + "\n" + " addl $8, %esp\n" + "\n" + " popl %edx\n" + " popl %ecx\n" + " popl %eax\n" + " jmp __afl_store\n" + "\n" + "__afl_die:\n" + "\n" + " xorl %eax, %eax\n" + " call _exit\n" + "\n" + "__afl_setup_abort:\n" + "\n" + " /* Record setup failure so that we don't keep calling\n" + " shmget() / shmat() over and over again. */\n" + "\n" + " incb __afl_setup_failure\n" + " popl %ecx\n" + " popl %eax\n" + " jmp __afl_return\n" + "\n" + ".AFL_VARS:\n" + "\n" + " .comm __afl_area_ptr, 4, 32\n" + " .comm __afl_setup_failure, 1, 32\n" +#ifndef COVERAGE_ONLY + " .comm __afl_prev_loc, 4, 32\n" +#endif /* !COVERAGE_ONLY */ + " .comm __afl_fork_pid, 4, 32\n" + " .comm __afl_temp, 4, 32\n" + "\n" + ".AFL_SHM_ENV:\n" + " .asciz \"" SHM_ENV_VAR "\"\n" + "\n" + "/* --- END --- */\n" + "\n"; + +/* The OpenBSD hack is due to lahf and sahf not being recognized by some + versions of binutils: http://marc.info/?l=openbsd-cvs&m=141636589924400 + + The Apple code is a bit different when calling libc functions because + they are doing relocations differently from everybody else. We also need + to work around the crash issue with .lcomm and the fact that they don't + recognize .string. */ + +#ifdef __APPLE__ +# define CALL_L64(str) "call _" str "\n" +#else +# define CALL_L64(str) "call " str "@PLT\n" +#endif /* ^__APPLE__ */ + +static const u8* main_payload_64 = + + "\n" + "/* --- AFL MAIN PAYLOAD (64-BIT) --- */\n" + "\n" + ".text\n" + ".att_syntax\n" + ".code64\n" + ".align 8\n" + "\n" + "__afl_maybe_log:\n" + "\n" +#if defined(__OpenBSD__) || (defined(__FreeBSD__) && (__FreeBSD__ < 9)) + " .byte 0x9f /* lahf */\n" +#else + " lahf\n" +#endif /* ^__OpenBSD__, etc */ + " seto %al\n" + "\n" + " /* Check if SHM region is already mapped. */\n" + "\n" + " movq __afl_area_ptr(%rip), %rdx\n" + " testq %rdx, %rdx\n" + " je __afl_setup\n" + "\n" + "__afl_store:\n" + "\n" + " /* Calculate and store hit for the code location specified in rcx. */\n" + "\n" +#ifndef COVERAGE_ONLY + " xorq __afl_prev_loc(%rip), %rcx\n" + " xorq %rcx, __afl_prev_loc(%rip)\n" + " shrq $1, __afl_prev_loc(%rip)\n" +#endif /* ^!COVERAGE_ONLY */ + "\n" +#ifdef SKIP_COUNTS + " orb $1, (%rdx, %rcx, 1)\n" +#else + " incb (%rdx, %rcx, 1)\n" +#endif /* ^SKIP_COUNTS */ + "\n" + "__afl_return:\n" + "\n" + " addb $127, %al\n" +#if defined(__OpenBSD__) || (defined(__FreeBSD__) && (__FreeBSD__ < 9)) + " .byte 0x9e /* sahf */\n" +#else + " sahf\n" +#endif /* ^__OpenBSD__, etc */ + " ret\n" + "\n" + ".align 8\n" + "\n" + "__afl_setup:\n" + "\n" + " /* Do not retry setup if we had previous failures. */\n" + "\n" + " cmpb $0, __afl_setup_failure(%rip)\n" + " jne __afl_return\n" + "\n" + " /* Check out if we have a global pointer on file. */\n" + "\n" +#ifndef __APPLE__ + " movq __afl_global_area_ptr@GOTPCREL(%rip), %rdx\n" + " movq (%rdx), %rdx\n" +#else + " movq __afl_global_area_ptr(%rip), %rdx\n" +#endif /* !^__APPLE__ */ + " testq %rdx, %rdx\n" + " je __afl_setup_first\n" + "\n" + " movq %rdx, __afl_area_ptr(%rip)\n" + " jmp __afl_store\n" + "\n" + "__afl_setup_first:\n" + "\n" + " /* Save everything that is not yet saved and that may be touched by\n" + " getenv() and several other libcalls we'll be relying on. */\n" + "\n" + " leaq -352(%rsp), %rsp\n" + "\n" + " movq %rax, 0(%rsp)\n" + " movq %rcx, 8(%rsp)\n" + " movq %rdi, 16(%rsp)\n" + " movq %rsi, 32(%rsp)\n" + " movq %r8, 40(%rsp)\n" + " movq %r9, 48(%rsp)\n" + " movq %r10, 56(%rsp)\n" + " movq %r11, 64(%rsp)\n" + "\n" + " movq %xmm0, 96(%rsp)\n" + " movq %xmm1, 112(%rsp)\n" + " movq %xmm2, 128(%rsp)\n" + " movq %xmm3, 144(%rsp)\n" + " movq %xmm4, 160(%rsp)\n" + " movq %xmm5, 176(%rsp)\n" + " movq %xmm6, 192(%rsp)\n" + " movq %xmm7, 208(%rsp)\n" + " movq %xmm8, 224(%rsp)\n" + " movq %xmm9, 240(%rsp)\n" + " movq %xmm10, 256(%rsp)\n" + " movq %xmm11, 272(%rsp)\n" + " movq %xmm12, 288(%rsp)\n" + " movq %xmm13, 304(%rsp)\n" + " movq %xmm14, 320(%rsp)\n" + " movq %xmm15, 336(%rsp)\n" + "\n" + " /* Map SHM, jumping to __afl_setup_abort if something goes wrong. */\n" + "\n" + " /* The 64-bit ABI requires 16-byte stack alignment. We'll keep the\n" + " original stack ptr in the callee-saved r12. */\n" + "\n" + " pushq %r12\n" + " movq %rsp, %r12\n" + " subq $16, %rsp\n" + " andq $0xfffffffffffffff0, %rsp\n" + "\n" + " leaq .AFL_SHM_ENV(%rip), %rdi\n" + CALL_L64("getenv") + "\n" + " testq %rax, %rax\n" + " je __afl_setup_abort\n" + "\n" + " movq %rax, %rdi\n" + CALL_L64("atoi") + "\n" + " xorq %rdx, %rdx /* shmat flags */\n" + " xorq %rsi, %rsi /* requested addr */\n" + " movq %rax, %rdi /* SHM ID */\n" + CALL_L64("shmat") + "\n" + " cmpq $-1, %rax\n" + " je __afl_setup_abort\n" + "\n" + " /* Store the address of the SHM region. */\n" + "\n" + " movq %rax, %rdx\n" + " movq %rax, __afl_area_ptr(%rip)\n" + "\n" +#ifdef __APPLE__ + " movq %rax, __afl_global_area_ptr(%rip)\n" +#else + " movq __afl_global_area_ptr@GOTPCREL(%rip), %rdx\n" + " movq %rax, (%rdx)\n" +#endif /* ^__APPLE__ */ + " movq %rax, %rdx\n" + "\n" + "__afl_forkserver:\n" + "\n" + " /* Enter the fork server mode to avoid the overhead of execve() calls. We\n" + " push rdx (area ptr) twice to keep stack alignment neat. */\n" + "\n" + " pushq %rdx\n" + " pushq %rdx\n" + "\n" + " /* Phone home and tell the parent that we're OK. (Note that signals with\n" + " no SA_RESTART will mess it up). If this fails, assume that the fd is\n" + " closed because we were execve()d from an instrumented binary, or because\n" + " the parent doesn't want to use the fork server. */\n" + "\n" + " movq $4, %rdx /* length */\n" + " leaq __afl_temp(%rip), %rsi /* data */\n" + " movq $" STRINGIFY((FORKSRV_FD + 1)) ", %rdi /* file desc */\n" + CALL_L64("write") + "\n" + " cmpq $4, %rax\n" + " jne __afl_fork_resume\n" + "\n" + "__afl_fork_wait_loop:\n" + "\n" + " /* Wait for parent by reading from the pipe. Abort if read fails. */\n" + "\n" + " movq $4, %rdx /* length */\n" + " leaq __afl_temp(%rip), %rsi /* data */\n" + " movq $" STRINGIFY(FORKSRV_FD) ", %rdi /* file desc */\n" + CALL_L64("read") + " cmpq $4, %rax\n" + " jne __afl_die\n" + "\n" + " /* Once woken up, create a clone of our process. This is an excellent use\n" + " case for syscall(__NR_clone, 0, CLONE_PARENT), but glibc boneheadedly\n" + " caches getpid() results and offers no way to update the value, breaking\n" + " abort(), raise(), and a bunch of other things :-( */\n" + "\n" + CALL_L64("fork") + " cmpq $0, %rax\n" + " jl __afl_die\n" + " je __afl_fork_resume\n" + "\n" + " /* In parent process: write PID to pipe, then wait for child. */\n" + "\n" + " movl %eax, __afl_fork_pid(%rip)\n" + "\n" + " movq $4, %rdx /* length */\n" + " leaq __afl_fork_pid(%rip), %rsi /* data */\n" + " movq $" STRINGIFY((FORKSRV_FD + 1)) ", %rdi /* file desc */\n" + CALL_L64("write") + "\n" + " movq $0, %rdx /* no flags */\n" + " leaq __afl_temp(%rip), %rsi /* status */\n" + " movq __afl_fork_pid(%rip), %rdi /* PID */\n" + CALL_L64("waitpid") + " cmpq $0, %rax\n" + " jle __afl_die\n" + "\n" + " /* Relay wait status to pipe, then loop back. */\n" + "\n" + " movq $4, %rdx /* length */\n" + " leaq __afl_temp(%rip), %rsi /* data */\n" + " movq $" STRINGIFY((FORKSRV_FD + 1)) ", %rdi /* file desc */\n" + CALL_L64("write") + "\n" + " jmp __afl_fork_wait_loop\n" + "\n" + "__afl_fork_resume:\n" + "\n" + " /* In child process: close fds, resume execution. */\n" + "\n" + " movq $" STRINGIFY(FORKSRV_FD) ", %rdi\n" + CALL_L64("close") + "\n" + " movq $" STRINGIFY((FORKSRV_FD + 1)) ", %rdi\n" + CALL_L64("close") + "\n" + " popq %rdx\n" + " popq %rdx\n" + "\n" + " movq %r12, %rsp\n" + " popq %r12\n" + "\n" + " movq 0(%rsp), %rax\n" + " movq 8(%rsp), %rcx\n" + " movq 16(%rsp), %rdi\n" + " movq 32(%rsp), %rsi\n" + " movq 40(%rsp), %r8\n" + " movq 48(%rsp), %r9\n" + " movq 56(%rsp), %r10\n" + " movq 64(%rsp), %r11\n" + "\n" + " movq 96(%rsp), %xmm0\n" + " movq 112(%rsp), %xmm1\n" + " movq 128(%rsp), %xmm2\n" + " movq 144(%rsp), %xmm3\n" + " movq 160(%rsp), %xmm4\n" + " movq 176(%rsp), %xmm5\n" + " movq 192(%rsp), %xmm6\n" + " movq 208(%rsp), %xmm7\n" + " movq 224(%rsp), %xmm8\n" + " movq 240(%rsp), %xmm9\n" + " movq 256(%rsp), %xmm10\n" + " movq 272(%rsp), %xmm11\n" + " movq 288(%rsp), %xmm12\n" + " movq 304(%rsp), %xmm13\n" + " movq 320(%rsp), %xmm14\n" + " movq 336(%rsp), %xmm15\n" + "\n" + " leaq 352(%rsp), %rsp\n" + "\n" + " jmp __afl_store\n" + "\n" + "__afl_die:\n" + "\n" + " xorq %rax, %rax\n" + CALL_L64("_exit") + "\n" + "__afl_setup_abort:\n" + "\n" + " /* Record setup failure so that we don't keep calling\n" + " shmget() / shmat() over and over again. */\n" + "\n" + " incb __afl_setup_failure(%rip)\n" + "\n" + " movq %r12, %rsp\n" + " popq %r12\n" + "\n" + " movq 0(%rsp), %rax\n" + " movq 8(%rsp), %rcx\n" + " movq 16(%rsp), %rdi\n" + " movq 32(%rsp), %rsi\n" + " movq 40(%rsp), %r8\n" + " movq 48(%rsp), %r9\n" + " movq 56(%rsp), %r10\n" + " movq 64(%rsp), %r11\n" + "\n" + " movq 96(%rsp), %xmm0\n" + " movq 112(%rsp), %xmm1\n" + " movq 128(%rsp), %xmm2\n" + " movq 144(%rsp), %xmm3\n" + " movq 160(%rsp), %xmm4\n" + " movq 176(%rsp), %xmm5\n" + " movq 192(%rsp), %xmm6\n" + " movq 208(%rsp), %xmm7\n" + " movq 224(%rsp), %xmm8\n" + " movq 240(%rsp), %xmm9\n" + " movq 256(%rsp), %xmm10\n" + " movq 272(%rsp), %xmm11\n" + " movq 288(%rsp), %xmm12\n" + " movq 304(%rsp), %xmm13\n" + " movq 320(%rsp), %xmm14\n" + " movq 336(%rsp), %xmm15\n" + "\n" + " leaq 352(%rsp), %rsp\n" + "\n" + " jmp __afl_return\n" + "\n" + ".AFL_VARS:\n" + "\n" + +#ifdef __APPLE__ + + " .comm __afl_area_ptr, 8\n" +#ifndef COVERAGE_ONLY + " .comm __afl_prev_loc, 8\n" +#endif /* !COVERAGE_ONLY */ + " .comm __afl_fork_pid, 4\n" + " .comm __afl_temp, 4\n" + " .comm __afl_setup_failure, 1\n" + +#else + + " .lcomm __afl_area_ptr, 8\n" +#ifndef COVERAGE_ONLY + " .lcomm __afl_prev_loc, 8\n" +#endif /* !COVERAGE_ONLY */ + " .lcomm __afl_fork_pid, 4\n" + " .lcomm __afl_temp, 4\n" + " .lcomm __afl_setup_failure, 1\n" + +#endif /* ^__APPLE__ */ + + " .comm __afl_global_area_ptr, 8, 8\n" + "\n" + ".AFL_SHM_ENV:\n" + " .asciz \"" SHM_ENV_VAR "\"\n" + "\n" + "/* --- END --- */\n" + "\n"; + +#endif /* !_HAVE_AFL_AS_H */ diff --git a/src/afl-cmin b/src/afl-cmin new file mode 100644 index 0000000..e89b895 --- /dev/null +++ b/src/afl-cmin @@ -0,0 +1,461 @@ +#!/usr/bin/env bash +# +# american fuzzy lop - corpus minimization tool +# --------------------------------------------- +# +# Written and maintained by Michal Zalewski +# +# Copyright 2014, 2015 Google LLC All rights reserved. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at: +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# This tool tries to find the smallest subset of files in the input directory +# that still trigger the full range of instrumentation data points seen in +# the starting corpus. This has two uses: +# +# - Screening large corpora of input files before using them as a seed for +# afl-fuzz. The tool will remove functionally redundant files and likely +# leave you with a much smaller set. +# +# (In this case, you probably also want to consider running afl-tmin on +# the individual files later on to reduce their size.) +# +# - Minimizing the corpus generated organically by afl-fuzz, perhaps when +# planning to feed it to more resource-intensive tools. The tool achieves +# this by removing all entries that used to trigger unique behaviors in the +# past, but have been made obsolete by later finds. +# +# Note that the tool doesn't modify the files themselves. For that, you want +# afl-tmin. +# +# This script must use bash because other shells may have hardcoded limits on +# array sizes. +# + +echo "corpus minimization tool for afl-fuzz by " +echo + +######### +# SETUP # +######### + +# Process command-line options... + +MEM_LIMIT=100 +TIMEOUT=none + +unset IN_DIR OUT_DIR STDIN_FILE EXTRA_PAR MEM_LIMIT_GIVEN \ + AFL_CMIN_CRASHES_ONLY AFL_CMIN_ALLOW_ANY QEMU_MODE + +while getopts "+i:o:f:m:t:eQC" opt; do + + case "$opt" in + + "i") + IN_DIR="$OPTARG" + ;; + + "o") + OUT_DIR="$OPTARG" + ;; + "f") + STDIN_FILE="$OPTARG" + ;; + "m") + MEM_LIMIT="$OPTARG" + MEM_LIMIT_GIVEN=1 + ;; + "t") + TIMEOUT="$OPTARG" + ;; + "e") + EXTRA_PAR="$EXTRA_PAR -e" + ;; + "C") + export AFL_CMIN_CRASHES_ONLY=1 + ;; + "Q") + EXTRA_PAR="$EXTRA_PAR -Q" + test "$MEM_LIMIT_GIVEN" = "" && MEM_LIMIT=250 + QEMU_MODE=1 + ;; + "?") + exit 1 + ;; + + esac + +done + +shift $((OPTIND-1)) + +TARGET_BIN="$1" + +if [ "$TARGET_BIN" = "" -o "$IN_DIR" = "" -o "$OUT_DIR" = "" ]; then + + cat 1>&2 <<_EOF_ +Usage: $0 [ options ] -- /path/to/target_app [ ... ] + +Required parameters: + + -i dir - input directory with the starting corpus + -o dir - output directory for minimized files + +Execution control settings: + + -f file - location read by the fuzzed program (stdin) + -m megs - memory limit for child process ($MEM_LIMIT MB) + -t msec - run time limit for child process (none) + -Q - use binary-only instrumentation (QEMU mode) + +Minimization settings: + + -C - keep crashing inputs, reject everything else + -e - solve for edge coverage only, ignore hit counts + +For additional tips, please consult docs/README. + +_EOF_ + exit 1 +fi + +# Do a sanity check to discourage the use of /tmp, since we can't really +# handle this safely from a shell script. + +if [ "$AFL_ALLOW_TMP" = "" ]; then + + echo "$IN_DIR" | grep -qE '^(/var)?/tmp/' + T1="$?" + + echo "$TARGET_BIN" | grep -qE '^(/var)?/tmp/' + T2="$?" + + echo "$OUT_DIR" | grep -qE '^(/var)?/tmp/' + T3="$?" + + echo "$STDIN_FILE" | grep -qE '^(/var)?/tmp/' + T4="$?" + + echo "$PWD" | grep -qE '^(/var)?/tmp/' + T5="$?" + + if [ "$T1" = "0" -o "$T2" = "0" -o "$T3" = "0" -o "$T4" = "0" -o "$T5" = "0" ]; then + echo "[-] Error: do not use this script in /tmp or /var/tmp." 1>&2 + exit 1 + fi + +fi + +# If @@ is specified, but there's no -f, let's come up with a temporary input +# file name. + +TRACE_DIR="$OUT_DIR/.traces" + +if [ "$STDIN_FILE" = "" ]; then + + if echo "$*" | grep -qF '@@'; then + STDIN_FILE="$TRACE_DIR/.cur_input" + fi + +fi + +# Check for obvious errors. + +if [ ! "$MEM_LIMIT" = "none" ]; then + + if [ "$MEM_LIMIT" -lt "5" ]; then + echo "[-] Error: dangerously low memory limit." 1>&2 + exit 1 + fi + +fi + +if [ ! "$TIMEOUT" = "none" ]; then + + if [ "$TIMEOUT" -lt "10" ]; then + echo "[-] Error: dangerously low timeout." 1>&2 + exit 1 + fi + +fi + +if [ ! -f "$TARGET_BIN" -o ! -x "$TARGET_BIN" ]; then + + TNEW="`which "$TARGET_BIN" 2>/dev/null`" + + if [ ! -f "$TNEW" -o ! -x "$TNEW" ]; then + echo "[-] Error: binary '$TARGET_BIN' not found or not executable." 1>&2 + exit 1 + fi + + TARGET_BIN="$TNEW" + +fi + +if [ "$AFL_SKIP_BIN_CHECK" = "" -a "$QEMU_MODE" = "" ]; then + + if ! grep -qF "__AFL_SHM_ID" "$TARGET_BIN"; then + echo "[-] Error: binary '$TARGET_BIN' doesn't appear to be instrumented." 1>&2 + exit 1 + fi + +fi + +if [ ! -d "$IN_DIR" ]; then + echo "[-] Error: directory '$IN_DIR' not found." 1>&2 + exit 1 +fi + +test -d "$IN_DIR/queue" && IN_DIR="$IN_DIR/queue" + +find "$OUT_DIR" -name 'id[:_]*' -maxdepth 1 -exec rm -- {} \; 2>/dev/null +rm -rf "$TRACE_DIR" 2>/dev/null + +rmdir "$OUT_DIR" 2>/dev/null + +if [ -d "$OUT_DIR" ]; then + echo "[-] Error: directory '$OUT_DIR' exists and is not empty - delete it first." 1>&2 + exit 1 +fi + +mkdir -m 700 -p "$TRACE_DIR" || exit 1 + +if [ ! "$STDIN_FILE" = "" ]; then + rm -f "$STDIN_FILE" || exit 1 + touch "$STDIN_FILE" || exit 1 +fi + +if [ "$AFL_PATH" = "" ]; then + SHOWMAP="${0%/afl-cmin}/afl-showmap" +else + SHOWMAP="$AFL_PATH/afl-showmap" +fi + +if [ ! -x "$SHOWMAP" ]; then + echo "[-] Error: can't find 'afl-showmap' - please set AFL_PATH." 1>&2 + rm -rf "$TRACE_DIR" + exit 1 +fi + +IN_COUNT=$((`ls -- "$IN_DIR" 2>/dev/null | wc -l`)) + +if [ "$IN_COUNT" = "0" ]; then + echo "[+] Hmm, no inputs in the target directory. Nothing to be done." + rm -rf "$TRACE_DIR" + exit 1 +fi + +FIRST_FILE=`ls "$IN_DIR" | head -1` + +# Make sure that we're not dealing with a directory. + +if [ -d "$IN_DIR/$FIRST_FILE" ]; then + echo "[-] Error: The target directory contains subdirectories - please fix." 1>&2 + rm -rf "$TRACE_DIR" + exit 1 +fi + +# Check for the more efficient way to copy files... + +if ln "$IN_DIR/$FIRST_FILE" "$TRACE_DIR/.link_test" 2>/dev/null; then + CP_TOOL=ln +else + CP_TOOL=cp +fi + +# Make sure that we can actually get anything out of afl-showmap before we +# waste too much time. + +echo "[*] Testing the target binary..." + +if [ "$STDIN_FILE" = "" ]; then + + AFL_CMIN_ALLOW_ANY=1 "$SHOWMAP" -m "$MEM_LIMIT" -t "$TIMEOUT" -o "$TRACE_DIR/.run_test" -Z $EXTRA_PAR -- "$@" <"$IN_DIR/$FIRST_FILE" + +else + + cp "$IN_DIR/$FIRST_FILE" "$STDIN_FILE" + AFL_CMIN_ALLOW_ANY=1 "$SHOWMAP" -m "$MEM_LIMIT" -t "$TIMEOUT" -o "$TRACE_DIR/.run_test" -Z $EXTRA_PAR -A "$STDIN_FILE" -- "$@" &2 + test "$AFL_KEEP_TRACES" = "" && rm -rf "$TRACE_DIR" + exit 1 + +fi + +# Let's roll! + +############################# +# STEP 1: COLLECTING TRACES # +############################# + +echo "[*] Obtaining traces for input files in '$IN_DIR'..." + +( + + CUR=0 + + if [ "$STDIN_FILE" = "" ]; then + + while read -r fn; do + + CUR=$((CUR+1)) + printf "\\r Processing file $CUR/$IN_COUNT... " + + "$SHOWMAP" -m "$MEM_LIMIT" -t "$TIMEOUT" -o "$TRACE_DIR/$fn" -Z $EXTRA_PAR -- "$@" <"$IN_DIR/$fn" + + done < <(ls "$IN_DIR") + + else + + while read -r fn; do + + CUR=$((CUR+1)) + printf "\\r Processing file $CUR/$IN_COUNT... " + + cp "$IN_DIR/$fn" "$STDIN_FILE" + + "$SHOWMAP" -m "$MEM_LIMIT" -t "$TIMEOUT" -o "$TRACE_DIR/$fn" -Z $EXTRA_PAR -A "$STDIN_FILE" -- "$@" "$TRACE_DIR/.all_uniq" + +TUPLE_COUNT=$((`grep -c . "$TRACE_DIR/.all_uniq"`)) + +echo "[+] Found $TUPLE_COUNT unique tuples across $IN_COUNT files." + +##################################### +# STEP 3: SELECTING CANDIDATE FILES # +##################################### + +# The next step is to find the best candidate for each tuple. The "best" +# part is understood simply as the smallest input that includes a particular +# tuple in its trace. Empirical evidence suggests that this produces smaller +# datasets than more involved algorithms that could be still pulled off in +# a shell script. + +echo "[*] Finding best candidates for each tuple..." + +CUR=0 + +while read -r fn; do + + CUR=$((CUR+1)) + printf "\\r Processing file $CUR/$IN_COUNT... " + + sed "s#\$# $fn#" "$TRACE_DIR/$fn" >>"$TRACE_DIR/.candidate_list" + +done < <(ls -rS "$IN_DIR") + +echo + +############################## +# STEP 4: LOADING CANDIDATES # +############################## + +# At this point, we have a file of tuple-file pairs, sorted by file size +# in ascending order (as a consequence of ls -rS). By doing sort keyed +# only by tuple (-k 1,1) and configured to output only the first line for +# every key (-s -u), we end up with the smallest file for each tuple. + +echo "[*] Sorting candidate list (be patient)..." + +sort -k1,1 -s -u "$TRACE_DIR/.candidate_list" | \ + sed 's/^/BEST_FILE[/;s/ /]="/;s/$/"/' >"$TRACE_DIR/.candidate_script" + +if [ ! -s "$TRACE_DIR/.candidate_script" ]; then + echo "[-] Error: no traces obtained from test cases, check syntax!" 1>&2 + test "$AFL_KEEP_TRACES" = "" && rm -rf "$TRACE_DIR" + exit 1 +fi + +# The sed command converted the sorted list to a shell script that populates +# BEST_FILE[tuple]="fname". Let's load that! + +. "$TRACE_DIR/.candidate_script" + +########################## +# STEP 5: WRITING OUTPUT # +########################## + +# The final trick is to grab the top pick for each tuple, unless said tuple is +# already set due to the inclusion of an earlier candidate; and then put all +# tuples associated with the newly-added file to the "already have" list. The +# loop works from least popular tuples and toward the most common ones. + +echo "[*] Processing candidates and writing output files..." + +CUR=0 + +touch "$TRACE_DIR/.already_have" + +while read -r cnt tuple; do + + CUR=$((CUR+1)) + printf "\\r Processing tuple $CUR/$TUPLE_COUNT... " + + # If we already have this tuple, skip it. + + grep -q "^$tuple\$" "$TRACE_DIR/.already_have" && continue + + FN=${BEST_FILE[tuple]} + + $CP_TOOL "$IN_DIR/$FN" "$OUT_DIR/$FN" + + if [ "$((CUR % 5))" = "0" ]; then + sort -u "$TRACE_DIR/$FN" "$TRACE_DIR/.already_have" >"$TRACE_DIR/.tmp" + mv -f "$TRACE_DIR/.tmp" "$TRACE_DIR/.already_have" + else + cat "$TRACE_DIR/$FN" >>"$TRACE_DIR/.already_have" + fi + +done <"$TRACE_DIR/.all_uniq" + +echo + +OUT_COUNT=`ls -- "$OUT_DIR" | wc -l` + +if [ "$OUT_COUNT" = "1" ]; then + echo "[!] WARNING: All test cases had the same traces, check syntax!" +fi + +echo "[+] Narrowed down to $OUT_COUNT files, saved in '$OUT_DIR'." +echo + +test "$AFL_KEEP_TRACES" = "" && rm -rf "$TRACE_DIR" + +exit 0 diff --git a/src/afl-fuzz.c b/src/afl-fuzz.c new file mode 100644 index 0000000..46a216c --- /dev/null +++ b/src/afl-fuzz.c @@ -0,0 +1,8197 @@ +/* + Copyright 2013 Google LLC All rights reserved. + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at: + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +*/ + +/* + american fuzzy lop - fuzzer code + -------------------------------- + + Written and maintained by Michal Zalewski + + Forkserver design by Jann Horn + + This is the real deal: the program takes an instrumented binary and + attempts a variety of basic fuzzing tricks, paying close attention to + how they affect the execution path. + +*/ + +#define AFL_MAIN +#include "android-ashmem.h" +#define MESSAGES_TO_STDOUT + +#ifndef _GNU_SOURCE +#define _GNU_SOURCE +#endif +#define _FILE_OFFSET_BITS 64 + +#include "config.h" +#include "types.h" +#include "debug.h" +#include "alloc-inl.h" +#include "hash.h" + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#if defined(__APPLE__) || defined(__FreeBSD__) || defined (__OpenBSD__) +# include +#endif /* __APPLE__ || __FreeBSD__ || __OpenBSD__ */ + +/* For systems that have sched_setaffinity; right now just Linux, but one + can hope... */ + +#ifdef __linux__ +# define HAVE_AFFINITY 1 +#endif /* __linux__ */ + +/* A toggle to export some variables when building as a library. Not very + useful for the general public. */ + +#ifdef AFL_LIB +# define EXP_ST +#else +# define EXP_ST static +#endif /* ^AFL_LIB */ + +/* Lots of globals, but mostly for the status UI and other things where it + really makes no sense to haul them around as function parameters. */ + + +EXP_ST u8 *in_dir, /* Input directory with test cases */ + *out_file, /* File to fuzz, if any */ + *out_dir, /* Working & output directory */ + *sync_dir, /* Synchronization directory */ + *sync_id, /* Fuzzer ID */ + *use_banner, /* Display banner */ + *in_bitmap, /* Input bitmap */ + *doc_path, /* Path to documentation dir */ + *target_path, /* Path to target binary */ + *orig_cmdline; /* Original command line */ + +EXP_ST u32 exec_tmout = EXEC_TIMEOUT; /* Configurable exec timeout (ms) */ +static u32 hang_tmout = EXEC_TIMEOUT; /* Timeout used for hang det (ms) */ + +EXP_ST u64 mem_limit = MEM_LIMIT; /* Memory cap for child (MB) */ + +EXP_ST u32 cpu_to_bind = 0; /* id of free CPU core to bind */ + +static u32 stats_update_freq = 1; /* Stats update frequency (execs) */ + +EXP_ST u8 skip_deterministic, /* Skip deterministic stages? */ + force_deterministic, /* Force deterministic stages? */ + use_splicing, /* Recombine input files? */ + dumb_mode, /* Run in non-instrumented mode? */ + score_changed, /* Scoring for favorites changed? */ + kill_signal, /* Signal that killed the child */ + resuming_fuzz, /* Resuming an older fuzzing job? */ + timeout_given, /* Specific timeout given? */ + cpu_to_bind_given, /* Specified cpu_to_bind given? */ + not_on_tty, /* stdout is not a tty */ + term_too_small, /* terminal dimensions too small */ + uses_asan, /* Target uses ASAN? */ + no_forkserver, /* Disable forkserver? */ + crash_mode, /* Crash mode! Yeah! */ + in_place_resume, /* Attempt in-place resume? */ + auto_changed, /* Auto-generated tokens changed? */ + no_cpu_meter_red, /* Feng shui on the status screen */ + no_arith, /* Skip most arithmetic ops */ + shuffle_queue, /* Shuffle input queue? */ + bitmap_changed = 1, /* Time to update bitmap? */ + qemu_mode, /* Running in QEMU mode? */ + skip_requested, /* Skip request, via SIGUSR1 */ + run_over10m, /* Run time over 10 minutes? */ + persistent_mode, /* Running in persistent mode? */ + deferred_mode, /* Deferred forkserver mode? */ + fast_cal; /* Try to calibrate faster? */ + +static s32 out_fd, /* Persistent fd for out_file */ + dev_urandom_fd = -1, /* Persistent fd for /dev/urandom */ + dev_null_fd = -1, /* Persistent fd for /dev/null */ + fsrv_ctl_fd, /* Fork server control pipe (write) */ + fsrv_st_fd; /* Fork server status pipe (read) */ + +static s32 forksrv_pid, /* PID of the fork server */ + child_pid = -1, /* PID of the fuzzed program */ + out_dir_fd = -1; /* FD of the lock file */ + +EXP_ST u8* trace_bits; /* SHM with instrumentation bitmap */ + +EXP_ST u8 virgin_bits[MAP_SIZE], /* Regions yet untouched by fuzzing */ + virgin_tmout[MAP_SIZE], /* Bits we haven't seen in tmouts */ + virgin_crash[MAP_SIZE]; /* Bits we haven't seen in crashes */ + +static u8 var_bytes[MAP_SIZE]; /* Bytes that appear to be variable */ + +static s32 shm_id; /* ID of the SHM region */ + +static volatile u8 stop_soon, /* Ctrl-C pressed? */ + clear_screen = 1, /* Window resized? */ + child_timed_out; /* Traced process timed out? */ + +EXP_ST u32 queued_paths, /* Total number of queued testcases */ + queued_variable, /* Testcases with variable behavior */ + queued_at_start, /* Total number of initial inputs */ + queued_discovered, /* Items discovered during this run */ + queued_imported, /* Items imported via -S */ + queued_favored, /* Paths deemed favorable */ + queued_with_cov, /* Paths with new coverage bytes */ + pending_not_fuzzed, /* Queued but not done yet */ + pending_favored, /* Pending favored paths */ + cur_skipped_paths, /* Abandoned inputs in cur cycle */ + cur_depth, /* Current path depth */ + max_depth, /* Max path depth */ + useless_at_start, /* Number of useless starting paths */ + var_byte_count, /* Bitmap bytes with var behavior */ + current_entry, /* Current queue entry ID */ + havoc_div = 1; /* Cycle count divisor for havoc */ + +EXP_ST u64 total_crashes, /* Total number of crashes */ + unique_crashes, /* Crashes with unique signatures */ + total_tmouts, /* Total number of timeouts */ + unique_tmouts, /* Timeouts with unique signatures */ + unique_hangs, /* Hangs with unique signatures */ + total_execs, /* Total execve() calls */ + slowest_exec_ms, /* Slowest testcase non hang in ms */ + start_time, /* Unix start time (ms) */ + last_path_time, /* Time for most recent path (ms) */ + last_crash_time, /* Time for most recent crash (ms) */ + last_hang_time, /* Time for most recent hang (ms) */ + last_crash_execs, /* Exec counter at last crash */ + queue_cycle, /* Queue round counter */ + cycles_wo_finds, /* Cycles without any new paths */ + trim_execs, /* Execs done to trim input files */ + bytes_trim_in, /* Bytes coming into the trimmer */ + bytes_trim_out, /* Bytes coming outa the trimmer */ + blocks_eff_total, /* Blocks subject to effector maps */ + blocks_eff_select; /* Blocks selected as fuzzable */ + +static u32 subseq_tmouts; /* Number of timeouts in a row */ + +static u8 *stage_name = "init", /* Name of the current fuzz stage */ + *stage_short, /* Short stage name */ + *syncing_party; /* Currently syncing with... */ + +static s32 stage_cur, stage_max; /* Stage progression */ +static s32 splicing_with = -1; /* Splicing with which test case? */ + +static u32 master_id, master_max; /* Master instance job splitting */ + +static u32 syncing_case; /* Syncing with case #... */ + +static s32 stage_cur_byte, /* Byte offset of current stage op */ + stage_cur_val; /* Value used for stage op */ + +static u8 stage_val_type; /* Value type (STAGE_VAL_*) */ + +static u64 stage_finds[32], /* Patterns found per fuzz stage */ + stage_cycles[32]; /* Execs per fuzz stage */ + +static u32 rand_cnt; /* Random number counter */ + +static u64 total_cal_us, /* Total calibration time (us) */ + total_cal_cycles; /* Total calibration cycles */ + +static u64 total_bitmap_size, /* Total bit count for all bitmaps */ + total_bitmap_entries; /* Number of bitmaps counted */ + +static s32 cpu_core_count; /* CPU core count */ + +#ifdef HAVE_AFFINITY + +static s32 cpu_aff = -1; /* Selected CPU core */ + +#endif /* HAVE_AFFINITY */ + +static FILE* plot_file; /* Gnuplot output file */ + +struct queue_entry { + + u8* fname; /* File name for the test case */ + u32 len; /* Input length */ + + u8 cal_failed, /* Calibration failed? */ + trim_done, /* Trimmed? */ + was_fuzzed, /* Had any fuzzing done yet? */ + passed_det, /* Deterministic stages passed? */ + has_new_cov, /* Triggers new coverage? */ + var_behavior, /* Variable behavior? */ + favored, /* Currently favored? */ + fs_redundant; /* Marked as redundant in the fs? */ + + u32 bitmap_size, /* Number of bits set in bitmap */ + exec_cksum; /* Checksum of the execution trace */ + + u64 exec_us, /* Execution time (us) */ + handicap, /* Number of queue cycles behind */ + depth; /* Path depth */ + + u8* trace_mini; /* Trace bytes, if kept */ + u32 tc_ref; /* Trace bytes ref count */ + + struct queue_entry *next, /* Next element, if any */ + *next_100; /* 100 elements ahead */ + +}; + +static struct queue_entry *queue, /* Fuzzing queue (linked list) */ + *queue_cur, /* Current offset within the queue */ + *queue_top, /* Top of the list */ + *q_prev100; /* Previous 100 marker */ + +static struct queue_entry* + top_rated[MAP_SIZE]; /* Top entries for bitmap bytes */ + +struct extra_data { + u8* data; /* Dictionary token data */ + u32 len; /* Dictionary token length */ + u32 hit_cnt; /* Use count in the corpus */ +}; + +static struct extra_data* extras; /* Extra tokens to fuzz with */ +static u32 extras_cnt; /* Total number of tokens read */ + +static struct extra_data* a_extras; /* Automatically selected extras */ +static u32 a_extras_cnt; /* Total number of tokens available */ + +static u8* (*post_handler)(u8* buf, u32* len); + +/* Interesting values, as per config.h */ + +static s8 interesting_8[] = { INTERESTING_8 }; +static s16 interesting_16[] = { INTERESTING_8, INTERESTING_16 }; +static s32 interesting_32[] = { INTERESTING_8, INTERESTING_16, INTERESTING_32 }; + +/* Fuzzing stages */ + +enum { + /* 00 */ STAGE_FLIP1, + /* 01 */ STAGE_FLIP2, + /* 02 */ STAGE_FLIP4, + /* 03 */ STAGE_FLIP8, + /* 04 */ STAGE_FLIP16, + /* 05 */ STAGE_FLIP32, + /* 06 */ STAGE_ARITH8, + /* 07 */ STAGE_ARITH16, + /* 08 */ STAGE_ARITH32, + /* 09 */ STAGE_INTEREST8, + /* 10 */ STAGE_INTEREST16, + /* 11 */ STAGE_INTEREST32, + /* 12 */ STAGE_EXTRAS_UO, + /* 13 */ STAGE_EXTRAS_UI, + /* 14 */ STAGE_EXTRAS_AO, + /* 15 */ STAGE_HAVOC, + /* 16 */ STAGE_SPLICE +}; + +/* Stage value types */ + +enum { + /* 00 */ STAGE_VAL_NONE, + /* 01 */ STAGE_VAL_LE, + /* 02 */ STAGE_VAL_BE +}; + +/* Execution status fault codes */ + +enum { + /* 00 */ FAULT_NONE, + /* 01 */ FAULT_TMOUT, + /* 02 */ FAULT_CRASH, + /* 03 */ FAULT_ERROR, + /* 04 */ FAULT_NOINST, + /* 05 */ FAULT_NOBITS +}; + + +/* Get unix time in milliseconds */ + +static u64 get_cur_time(void) { + + struct timeval tv; + struct timezone tz; + + gettimeofday(&tv, &tz); + + return (tv.tv_sec * 1000ULL) + (tv.tv_usec / 1000); + +} + + +/* Get unix time in microseconds */ + +static u64 get_cur_time_us(void) { + + struct timeval tv; + struct timezone tz; + + gettimeofday(&tv, &tz); + + return (tv.tv_sec * 1000000ULL) + tv.tv_usec; + +} + + +/* Generate a random number (from 0 to limit - 1). This may + have slight bias. */ + +static inline u32 UR(u32 limit) { + + if (unlikely(!rand_cnt--)) { + + u32 seed[2]; + + ck_read(dev_urandom_fd, &seed, sizeof(seed), "/dev/urandom"); + + srandom(seed[0]); + rand_cnt = (RESEED_RNG / 2) + (seed[1] % RESEED_RNG); + + } + + return random() % limit; + +} + + +/* Shuffle an array of pointers. Might be slightly biased. */ + +static void shuffle_ptrs(void** ptrs, u32 cnt) { + + u32 i; + + for (i = 0; i < cnt - 2; i++) { + + u32 j = i + UR(cnt - i); + void *s = ptrs[i]; + ptrs[i] = ptrs[j]; + ptrs[j] = s; + + } + +} + + +#ifdef HAVE_AFFINITY + +/* Build a list of processes bound to specific cores. Returns -1 if nothing + can be found. Assumes an upper bound of 4k CPUs. */ + +static void bind_to_free_cpu(void) { + + DIR* d; + struct dirent* de; + cpu_set_t c; + + u8 cpu_used[4096] = { 0 }; + u32 i; + + if (cpu_core_count < 2) return; + + if (getenv("AFL_NO_AFFINITY")) { + + WARNF("Not binding to a CPU core (AFL_NO_AFFINITY set)."); + return; + + } + + d = opendir("/proc"); + + if (!d) { + + WARNF("Unable to access /proc - can't scan for free CPU cores."); + return; + + } + + ACTF("Checking CPU core loadout..."); + + /* Introduce some jitter, in case multiple AFL tasks are doing the same + thing at the same time... */ + + usleep(R(1000) * 250); + + /* Scan all /proc//status entries, checking for Cpus_allowed_list. + Flag all processes bound to a specific CPU using cpu_used[]. This will + fail for some exotic binding setups, but is likely good enough in almost + all real-world use cases. */ + + while ((de = readdir(d))) { + + u8* fn; + FILE* f; + u8 tmp[MAX_LINE]; + u8 has_vmsize = 0; + + if (!isdigit(de->d_name[0])) continue; + + fn = alloc_printf("/proc/%s/status", de->d_name); + + if (!(f = fopen(fn, "r"))) { + ck_free(fn); + continue; + } + + while (fgets(tmp, MAX_LINE, f)) { + + u32 hval; + + /* Processes without VmSize are probably kernel tasks. */ + + if (!strncmp(tmp, "VmSize:\t", 8)) has_vmsize = 1; + + if (!strncmp(tmp, "Cpus_allowed_list:\t", 19) && + !strchr(tmp, '-') && !strchr(tmp, ',') && + sscanf(tmp + 19, "%u", &hval) == 1 && hval < sizeof(cpu_used) && + has_vmsize) { + + cpu_used[hval] = 1; + break; + + } + + } + + ck_free(fn); + fclose(f); + + } + + closedir(d); + if (cpu_to_bind_given) { + + if (cpu_to_bind >= cpu_core_count) + FATAL("The CPU core id to bind should be between 0 and %u", cpu_core_count - 1); + + if (cpu_used[cpu_to_bind]) + FATAL("The CPU core #%u to bind is not free!", cpu_to_bind); + + i = cpu_to_bind; + + } else { + + for (i = 0; i < cpu_core_count; i++) if (!cpu_used[i]) break; + + } + + if (i == cpu_core_count) { + + SAYF("\n" cLRD "[-] " cRST + "Uh-oh, looks like all %u CPU cores on your system are allocated to\n" + " other instances of afl-fuzz (or similar CPU-locked tasks). Starting\n" + " another fuzzer on this machine is probably a bad plan, but if you are\n" + " absolutely sure, you can set AFL_NO_AFFINITY and try again.\n", + cpu_core_count); + + FATAL("No more free CPU cores"); + + } + + OKF("Found a free CPU core, binding to #%u.", i); + + cpu_aff = i; + + CPU_ZERO(&c); + CPU_SET(i, &c); + + if (sched_setaffinity(0, sizeof(c), &c)) + PFATAL("sched_setaffinity failed"); + +} + +#endif /* HAVE_AFFINITY */ + +#ifndef IGNORE_FINDS + +/* Helper function to compare buffers; returns first and last differing offset. We + use this to find reasonable locations for splicing two files. */ + +static void locate_diffs(u8* ptr1, u8* ptr2, u32 len, s32* first, s32* last) { + + s32 f_loc = -1; + s32 l_loc = -1; + u32 pos; + + for (pos = 0; pos < len; pos++) { + + if (*(ptr1++) != *(ptr2++)) { + + if (f_loc == -1) f_loc = pos; + l_loc = pos; + + } + + } + + *first = f_loc; + *last = l_loc; + + return; + +} + +#endif /* !IGNORE_FINDS */ + + +/* Describe integer. Uses 12 cyclic static buffers for return values. The value + returned should be five characters or less for all the integers we reasonably + expect to see. */ + +static u8* DI(u64 val) { + + static u8 tmp[12][16]; + static u8 cur; + + cur = (cur + 1) % 12; + +#define CHK_FORMAT(_divisor, _limit_mult, _fmt, _cast) do { \ + if (val < (_divisor) * (_limit_mult)) { \ + sprintf(tmp[cur], _fmt, ((_cast)val) / (_divisor)); \ + return tmp[cur]; \ + } \ + } while (0) + + /* 0-9999 */ + CHK_FORMAT(1, 10000, "%llu", u64); + + /* 10.0k - 99.9k */ + CHK_FORMAT(1000, 99.95, "%0.01fk", double); + + /* 100k - 999k */ + CHK_FORMAT(1000, 1000, "%lluk", u64); + + /* 1.00M - 9.99M */ + CHK_FORMAT(1000 * 1000, 9.995, "%0.02fM", double); + + /* 10.0M - 99.9M */ + CHK_FORMAT(1000 * 1000, 99.95, "%0.01fM", double); + + /* 100M - 999M */ + CHK_FORMAT(1000 * 1000, 1000, "%lluM", u64); + + /* 1.00G - 9.99G */ + CHK_FORMAT(1000LL * 1000 * 1000, 9.995, "%0.02fG", double); + + /* 10.0G - 99.9G */ + CHK_FORMAT(1000LL * 1000 * 1000, 99.95, "%0.01fG", double); + + /* 100G - 999G */ + CHK_FORMAT(1000LL * 1000 * 1000, 1000, "%lluG", u64); + + /* 1.00T - 9.99G */ + CHK_FORMAT(1000LL * 1000 * 1000 * 1000, 9.995, "%0.02fT", double); + + /* 10.0T - 99.9T */ + CHK_FORMAT(1000LL * 1000 * 1000 * 1000, 99.95, "%0.01fT", double); + + /* 100T+ */ + strcpy(tmp[cur], "infty"); + return tmp[cur]; + +} + + +/* Describe float. Similar to the above, except with a single + static buffer. */ + +static u8* DF(double val) { + + static u8 tmp[16]; + + if (val < 99.995) { + sprintf(tmp, "%0.02f", val); + return tmp; + } + + if (val < 999.95) { + sprintf(tmp, "%0.01f", val); + return tmp; + } + + return DI((u64)val); + +} + + +/* Describe integer as memory size. */ + +static u8* DMS(u64 val) { + + static u8 tmp[12][16]; + static u8 cur; + + cur = (cur + 1) % 12; + + /* 0-9999 */ + CHK_FORMAT(1, 10000, "%llu B", u64); + + /* 10.0k - 99.9k */ + CHK_FORMAT(1024, 99.95, "%0.01f kB", double); + + /* 100k - 999k */ + CHK_FORMAT(1024, 1000, "%llu kB", u64); + + /* 1.00M - 9.99M */ + CHK_FORMAT(1024 * 1024, 9.995, "%0.02f MB", double); + + /* 10.0M - 99.9M */ + CHK_FORMAT(1024 * 1024, 99.95, "%0.01f MB", double); + + /* 100M - 999M */ + CHK_FORMAT(1024 * 1024, 1000, "%llu MB", u64); + + /* 1.00G - 9.99G */ + CHK_FORMAT(1024LL * 1024 * 1024, 9.995, "%0.02f GB", double); + + /* 10.0G - 99.9G */ + CHK_FORMAT(1024LL * 1024 * 1024, 99.95, "%0.01f GB", double); + + /* 100G - 999G */ + CHK_FORMAT(1024LL * 1024 * 1024, 1000, "%llu GB", u64); + + /* 1.00T - 9.99G */ + CHK_FORMAT(1024LL * 1024 * 1024 * 1024, 9.995, "%0.02f TB", double); + + /* 10.0T - 99.9T */ + CHK_FORMAT(1024LL * 1024 * 1024 * 1024, 99.95, "%0.01f TB", double); + +#undef CHK_FORMAT + + /* 100T+ */ + strcpy(tmp[cur], "infty"); + return tmp[cur]; + +} + + +/* Describe time delta. Returns one static buffer, 34 chars of less. */ + +static u8* DTD(u64 cur_ms, u64 event_ms) { + + static u8 tmp[64]; + u64 delta; + s32 t_d, t_h, t_m, t_s; + + if (!event_ms) return "none seen yet"; + + delta = cur_ms - event_ms; + + t_d = delta / 1000 / 60 / 60 / 24; + t_h = (delta / 1000 / 60 / 60) % 24; + t_m = (delta / 1000 / 60) % 60; + t_s = (delta / 1000) % 60; + + sprintf(tmp, "%s days, %u hrs, %u min, %u sec", DI(t_d), t_h, t_m, t_s); + return tmp; + +} + + +/* Mark deterministic checks as done for a particular queue entry. We use the + .state file to avoid repeating deterministic fuzzing when resuming aborted + scans. */ + +static void mark_as_det_done(struct queue_entry* q) { + + u8* fn = strrchr(q->fname, '/'); + s32 fd; + + fn = alloc_printf("%s/queue/.state/deterministic_done/%s", out_dir, fn + 1); + + fd = open(fn, O_WRONLY | O_CREAT | O_EXCL, 0600); + if (fd < 0) PFATAL("Unable to create '%s'", fn); + close(fd); + + ck_free(fn); + + q->passed_det = 1; + +} + + +/* Mark as variable. Create symlinks if possible to make it easier to examine + the files. */ + +static void mark_as_variable(struct queue_entry* q) { + + u8 *fn = strrchr(q->fname, '/') + 1, *ldest; + + ldest = alloc_printf("../../%s", fn); + fn = alloc_printf("%s/queue/.state/variable_behavior/%s", out_dir, fn); + + if (symlink(ldest, fn)) { + + s32 fd = open(fn, O_WRONLY | O_CREAT | O_EXCL, 0600); + if (fd < 0) PFATAL("Unable to create '%s'", fn); + close(fd); + + } + + ck_free(ldest); + ck_free(fn); + + q->var_behavior = 1; + +} + + +/* Mark / unmark as redundant (edge-only). This is not used for restoring state, + but may be useful for post-processing datasets. */ + +static void mark_as_redundant(struct queue_entry* q, u8 state) { + + u8* fn; + s32 fd; + + if (state == q->fs_redundant) return; + + q->fs_redundant = state; + + fn = strrchr(q->fname, '/'); + fn = alloc_printf("%s/queue/.state/redundant_edges/%s", out_dir, fn + 1); + + if (state) { + + fd = open(fn, O_WRONLY | O_CREAT | O_EXCL, 0600); + if (fd < 0) PFATAL("Unable to create '%s'", fn); + close(fd); + + } else { + + if (unlink(fn)) PFATAL("Unable to remove '%s'", fn); + + } + + ck_free(fn); + +} + + +/* Append new test case to the queue. */ + +static void add_to_queue(u8* fname, u32 len, u8 passed_det) { + + struct queue_entry* q = ck_alloc(sizeof(struct queue_entry)); + + q->fname = fname; + q->len = len; + q->depth = cur_depth + 1; + q->passed_det = passed_det; + + if (q->depth > max_depth) max_depth = q->depth; + + if (queue_top) { + + queue_top->next = q; + queue_top = q; + + } else q_prev100 = queue = queue_top = q; + + queued_paths++; + pending_not_fuzzed++; + + cycles_wo_finds = 0; + + /* Set next_100 pointer for every 100th element (index 0, 100, etc) to allow faster iteration. */ + if ((queued_paths - 1) % 100 == 0 && queued_paths > 1) { + + q_prev100->next_100 = q; + q_prev100 = q; + + } + + last_path_time = get_cur_time(); + +} + + +/* Destroy the entire queue. */ + +EXP_ST void destroy_queue(void) { + + struct queue_entry *q = queue, *n; + + while (q) { + + n = q->next; + ck_free(q->fname); + ck_free(q->trace_mini); + ck_free(q); + q = n; + + } + +} + + +/* Write bitmap to file. The bitmap is useful mostly for the secret + -B option, to focus a separate fuzzing session on a particular + interesting input without rediscovering all the others. */ + +EXP_ST void write_bitmap(void) { + + u8* fname; + s32 fd; + + if (!bitmap_changed) return; + bitmap_changed = 0; + + fname = alloc_printf("%s/fuzz_bitmap", out_dir); + fd = open(fname, O_WRONLY | O_CREAT | O_TRUNC, 0600); + + if (fd < 0) PFATAL("Unable to open '%s'", fname); + + ck_write(fd, virgin_bits, MAP_SIZE, fname); + + close(fd); + ck_free(fname); + +} + + +/* Read bitmap from file. This is for the -B option again. */ + +EXP_ST void read_bitmap(u8* fname) { + + s32 fd = open(fname, O_RDONLY); + + if (fd < 0) PFATAL("Unable to open '%s'", fname); + + ck_read(fd, virgin_bits, MAP_SIZE, fname); + + close(fd); + +} + + +/* Check if the current execution path brings anything new to the table. + Update virgin bits to reflect the finds. Returns 1 if the only change is + the hit-count for a particular tuple; 2 if there are new tuples seen. + Updates the map, so subsequent calls will always return 0. + + This function is called after every exec() on a fairly large buffer, so + it needs to be fast. We do this in 32-bit and 64-bit flavors. */ + +static inline u8 has_new_bits(u8* virgin_map) { + +#ifdef WORD_SIZE_64 + + u64* current = (u64*)trace_bits; + u64* virgin = (u64*)virgin_map; + + u32 i = (MAP_SIZE >> 3); + +#else + + u32* current = (u32*)trace_bits; + u32* virgin = (u32*)virgin_map; + + u32 i = (MAP_SIZE >> 2); + +#endif /* ^WORD_SIZE_64 */ + + u8 ret = 0; + + while (i--) { + + /* Optimize for (*current & *virgin) == 0 - i.e., no bits in current bitmap + that have not been already cleared from the virgin map - since this will + almost always be the case. */ + + if (unlikely(*current) && unlikely(*current & *virgin)) { + + if (likely(ret < 2)) { + + u8* cur = (u8*)current; + u8* vir = (u8*)virgin; + + /* Looks like we have not found any new bytes yet; see if any non-zero + bytes in current[] are pristine in virgin[]. */ + +#ifdef WORD_SIZE_64 + + if ((cur[0] && vir[0] == 0xff) || (cur[1] && vir[1] == 0xff) || + (cur[2] && vir[2] == 0xff) || (cur[3] && vir[3] == 0xff) || + (cur[4] && vir[4] == 0xff) || (cur[5] && vir[5] == 0xff) || + (cur[6] && vir[6] == 0xff) || (cur[7] && vir[7] == 0xff)) ret = 2; + else ret = 1; + +#else + + if ((cur[0] && vir[0] == 0xff) || (cur[1] && vir[1] == 0xff) || + (cur[2] && vir[2] == 0xff) || (cur[3] && vir[3] == 0xff)) ret = 2; + else ret = 1; + +#endif /* ^WORD_SIZE_64 */ + + } + + *virgin &= ~*current; + + } + + current++; + virgin++; + + } + + if (ret && virgin_map == virgin_bits) bitmap_changed = 1; + + return ret; + +} + + +/* Count the number of bits set in the provided bitmap. Used for the status + screen several times every second, does not have to be fast. */ + +static u32 count_bits(u8* mem) { + + u32* ptr = (u32*)mem; + u32 i = (MAP_SIZE >> 2); + u32 ret = 0; + + while (i--) { + + u32 v = *(ptr++); + + /* This gets called on the inverse, virgin bitmap; optimize for sparse + data. */ + + if (v == 0xffffffff) { + ret += 32; + continue; + } + + v -= ((v >> 1) & 0x55555555); + v = (v & 0x33333333) + ((v >> 2) & 0x33333333); + ret += (((v + (v >> 4)) & 0xF0F0F0F) * 0x01010101) >> 24; + + } + + return ret; + +} + + +#define FF(_b) (0xff << ((_b) << 3)) + +/* Count the number of bytes set in the bitmap. Called fairly sporadically, + mostly to update the status screen or calibrate and examine confirmed + new paths. */ + +static u32 count_bytes(u8* mem) { + + u32* ptr = (u32*)mem; + u32 i = (MAP_SIZE >> 2); + u32 ret = 0; + + while (i--) { + + u32 v = *(ptr++); + + if (!v) continue; + if (v & FF(0)) ret++; + if (v & FF(1)) ret++; + if (v & FF(2)) ret++; + if (v & FF(3)) ret++; + + } + + return ret; + +} + + +/* Count the number of non-255 bytes set in the bitmap. Used strictly for the + status screen, several calls per second or so. */ + +static u32 count_non_255_bytes(u8* mem) { + + u32* ptr = (u32*)mem; + u32 i = (MAP_SIZE >> 2); + u32 ret = 0; + + while (i--) { + + u32 v = *(ptr++); + + /* This is called on the virgin bitmap, so optimize for the most likely + case. */ + + if (v == 0xffffffff) continue; + if ((v & FF(0)) != FF(0)) ret++; + if ((v & FF(1)) != FF(1)) ret++; + if ((v & FF(2)) != FF(2)) ret++; + if ((v & FF(3)) != FF(3)) ret++; + + } + + return ret; + +} + + +/* Destructively simplify trace by eliminating hit count information + and replacing it with 0x80 or 0x01 depending on whether the tuple + is hit or not. Called on every new crash or timeout, should be + reasonably fast. */ + +static const u8 simplify_lookup[256] = { + + [0] = 1, + [1 ... 255] = 128 + +}; + +#ifdef WORD_SIZE_64 + +static void simplify_trace(u64* mem) { + + u32 i = MAP_SIZE >> 3; + + while (i--) { + + /* Optimize for sparse bitmaps. */ + + if (unlikely(*mem)) { + + u8* mem8 = (u8*)mem; + + mem8[0] = simplify_lookup[mem8[0]]; + mem8[1] = simplify_lookup[mem8[1]]; + mem8[2] = simplify_lookup[mem8[2]]; + mem8[3] = simplify_lookup[mem8[3]]; + mem8[4] = simplify_lookup[mem8[4]]; + mem8[5] = simplify_lookup[mem8[5]]; + mem8[6] = simplify_lookup[mem8[6]]; + mem8[7] = simplify_lookup[mem8[7]]; + + } else *mem = 0x0101010101010101ULL; + + mem++; + + } + +} + +#else + +static void simplify_trace(u32* mem) { + + u32 i = MAP_SIZE >> 2; + + while (i--) { + + /* Optimize for sparse bitmaps. */ + + if (unlikely(*mem)) { + + u8* mem8 = (u8*)mem; + + mem8[0] = simplify_lookup[mem8[0]]; + mem8[1] = simplify_lookup[mem8[1]]; + mem8[2] = simplify_lookup[mem8[2]]; + mem8[3] = simplify_lookup[mem8[3]]; + + } else *mem = 0x01010101; + + mem++; + } + +} + +#endif /* ^WORD_SIZE_64 */ + + +/* Destructively classify execution counts in a trace. This is used as a + preprocessing step for any newly acquired traces. Called on every exec, + must be fast. */ + +static const u8 count_class_lookup8[256] = { + + [0] = 0, + [1] = 1, + [2] = 2, + [3] = 4, + [4 ... 7] = 8, + [8 ... 15] = 16, + [16 ... 31] = 32, + [32 ... 127] = 64, + [128 ... 255] = 128 + +}; + +static u16 count_class_lookup16[65536]; + + +EXP_ST void init_count_class16(void) { + + u32 b1, b2; + + for (b1 = 0; b1 < 256; b1++) + for (b2 = 0; b2 < 256; b2++) + count_class_lookup16[(b1 << 8) + b2] = + (count_class_lookup8[b1] << 8) | + count_class_lookup8[b2]; + +} + + +#ifdef WORD_SIZE_64 + +static inline void classify_counts(u64* mem) { + + u32 i = MAP_SIZE >> 3; + + while (i--) { + + /* Optimize for sparse bitmaps. */ + + if (unlikely(*mem)) { + + u16* mem16 = (u16*)mem; + + mem16[0] = count_class_lookup16[mem16[0]]; + mem16[1] = count_class_lookup16[mem16[1]]; + mem16[2] = count_class_lookup16[mem16[2]]; + mem16[3] = count_class_lookup16[mem16[3]]; + + } + + mem++; + + } + +} + +#else + +static inline void classify_counts(u32* mem) { + + u32 i = MAP_SIZE >> 2; + + while (i--) { + + /* Optimize for sparse bitmaps. */ + + if (unlikely(*mem)) { + + u16* mem16 = (u16*)mem; + + mem16[0] = count_class_lookup16[mem16[0]]; + mem16[1] = count_class_lookup16[mem16[1]]; + + } + + mem++; + + } + +} + +#endif /* ^WORD_SIZE_64 */ + + +/* Get rid of shared memory (atexit handler). */ + +static void remove_shm(void) { + + shmctl(shm_id, IPC_RMID, NULL); + +} + + +/* Compact trace bytes into a smaller bitmap. We effectively just drop the + count information here. This is called only sporadically, for some + new paths. */ + +static void minimize_bits(u8* dst, u8* src) { + + u32 i = 0; + + while (i < MAP_SIZE) { + + if (*(src++)) dst[i >> 3] |= 1 << (i & 7); + i++; + + } + +} + + +/* When we bump into a new path, we call this to see if the path appears + more "favorable" than any of the existing ones. The purpose of the + "favorables" is to have a minimal set of paths that trigger all the bits + seen in the bitmap so far, and focus on fuzzing them at the expense of + the rest. + + The first step of the process is to maintain a list of top_rated[] entries + for every byte in the bitmap. We win that slot if there is no previous + contender, or if the contender has a more favorable speed x size factor. */ + +static void update_bitmap_score(struct queue_entry* q) { + + u32 i; + u64 fav_factor = q->exec_us * q->len; + + /* For every byte set in trace_bits[], see if there is a previous winner, + and how it compares to us. */ + + for (i = 0; i < MAP_SIZE; i++) + + if (trace_bits[i]) { + + if (top_rated[i]) { + + /* Faster-executing or smaller test cases are favored. */ + + if (fav_factor > top_rated[i]->exec_us * top_rated[i]->len) continue; + + /* Looks like we're going to win. Decrease ref count for the + previous winner, discard its trace_bits[] if necessary. */ + + if (!--top_rated[i]->tc_ref) { + ck_free(top_rated[i]->trace_mini); + top_rated[i]->trace_mini = 0; + } + + } + + /* Insert ourselves as the new winner. */ + + top_rated[i] = q; + q->tc_ref++; + + if (!q->trace_mini) { + q->trace_mini = ck_alloc(MAP_SIZE >> 3); + minimize_bits(q->trace_mini, trace_bits); + } + + score_changed = 1; + + } + +} + + +/* The second part of the mechanism discussed above is a routine that + goes over top_rated[] entries, and then sequentially grabs winners for + previously-unseen bytes (temp_v) and marks them as favored, at least + until the next run. The favored entries are given more air time during + all fuzzing steps. */ + +static void cull_queue(void) { + + struct queue_entry* q; + static u8 temp_v[MAP_SIZE >> 3]; + u32 i; + + if (dumb_mode || !score_changed) return; + + score_changed = 0; + + memset(temp_v, 255, MAP_SIZE >> 3); + + queued_favored = 0; + pending_favored = 0; + + q = queue; + + while (q) { + q->favored = 0; + q = q->next; + } + + /* Let's see if anything in the bitmap isn't captured in temp_v. + If yes, and if it has a top_rated[] contender, let's use it. */ + + for (i = 0; i < MAP_SIZE; i++) + if (top_rated[i] && (temp_v[i >> 3] & (1 << (i & 7)))) { + + u32 j = MAP_SIZE >> 3; + + /* Remove all bits belonging to the current entry from temp_v. */ + + while (j--) + if (top_rated[i]->trace_mini[j]) + temp_v[j] &= ~top_rated[i]->trace_mini[j]; + + top_rated[i]->favored = 1; + queued_favored++; + + if (!top_rated[i]->was_fuzzed) pending_favored++; + + } + + q = queue; + + while (q) { + mark_as_redundant(q, !q->favored); + q = q->next; + } + +} + + +/* Configure shared memory and virgin_bits. This is called at startup. */ + +EXP_ST void setup_shm(void) { + + u8* shm_str; + + if (!in_bitmap) memset(virgin_bits, 255, MAP_SIZE); + + memset(virgin_tmout, 255, MAP_SIZE); + memset(virgin_crash, 255, MAP_SIZE); + + shm_id = shmget(IPC_PRIVATE, MAP_SIZE, IPC_CREAT | IPC_EXCL | 0600); + + if (shm_id < 0) PFATAL("shmget() failed"); + + atexit(remove_shm); + + shm_str = alloc_printf("%d", shm_id); + + /* If somebody is asking us to fuzz instrumented binaries in dumb mode, + we don't want them to detect instrumentation, since we won't be sending + fork server commands. This should be replaced with better auto-detection + later on, perhaps? */ + + if (!dumb_mode) setenv(SHM_ENV_VAR, shm_str, 1); + + ck_free(shm_str); + + trace_bits = shmat(shm_id, NULL, 0); + + if (trace_bits == (void *)-1) PFATAL("shmat() failed"); + +} + + +/* Load postprocessor, if available. */ + +static void setup_post(void) { + + void* dh; + u8* fn = getenv("AFL_POST_LIBRARY"); + u32 tlen = 6; + + if (!fn) return; + + ACTF("Loading postprocessor from '%s'...", fn); + + dh = dlopen(fn, RTLD_NOW); + if (!dh) FATAL("%s", dlerror()); + + post_handler = dlsym(dh, "afl_postprocess"); + if (!post_handler) FATAL("Symbol 'afl_postprocess' not found."); + + /* Do a quick test. It's better to segfault now than later =) */ + + post_handler("hello", &tlen); + + OKF("Postprocessor installed successfully."); + +} + + +/* Read all testcases from the input directory, then queue them for testing. + Called at startup. */ + +static void read_testcases(void) { + + struct dirent **nl; + s32 nl_cnt; + u32 i; + u8* fn; + + /* Auto-detect non-in-place resumption attempts. */ + + fn = alloc_printf("%s/queue", in_dir); + if (!access(fn, F_OK)) in_dir = fn; else ck_free(fn); + + ACTF("Scanning '%s'...", in_dir); + + /* We use scandir() + alphasort() rather than readdir() because otherwise, + the ordering of test cases would vary somewhat randomly and would be + difficult to control. */ + + nl_cnt = scandir(in_dir, &nl, NULL, alphasort); + + if (nl_cnt < 0) { + + if (errno == ENOENT || errno == ENOTDIR) + + SAYF("\n" cLRD "[-] " cRST + "The input directory does not seem to be valid - try again. The fuzzer needs\n" + " one or more test case to start with - ideally, a small file under 1 kB\n" + " or so. The cases must be stored as regular files directly in the input\n" + " directory.\n"); + + PFATAL("Unable to open '%s'", in_dir); + + } + + if (shuffle_queue && nl_cnt > 1) { + + ACTF("Shuffling queue..."); + shuffle_ptrs((void**)nl, nl_cnt); + + } + + for (i = 0; i < nl_cnt; i++) { + + struct stat st; + + u8* fn = alloc_printf("%s/%s", in_dir, nl[i]->d_name); + u8* dfn = alloc_printf("%s/.state/deterministic_done/%s", in_dir, nl[i]->d_name); + + u8 passed_det = 0; + + free(nl[i]); /* not tracked */ + + if (lstat(fn, &st) || access(fn, R_OK)) + PFATAL("Unable to access '%s'", fn); + + /* This also takes care of . and .. */ + + if (!S_ISREG(st.st_mode) || !st.st_size || strstr(fn, "/README.testcases")) { + + ck_free(fn); + ck_free(dfn); + continue; + + } + + if (st.st_size > MAX_FILE) + FATAL("Test case '%s' is too big (%s, limit is %s)", fn, + DMS(st.st_size), DMS(MAX_FILE)); + + /* Check for metadata that indicates that deterministic fuzzing + is complete for this entry. We don't want to repeat deterministic + fuzzing when resuming aborted scans, because it would be pointless + and probably very time-consuming. */ + + if (!access(dfn, F_OK)) passed_det = 1; + ck_free(dfn); + + add_to_queue(fn, st.st_size, passed_det); + + } + + free(nl); /* not tracked */ + + if (!queued_paths) { + + SAYF("\n" cLRD "[-] " cRST + "Looks like there are no valid test cases in the input directory! The fuzzer\n" + " needs one or more test case to start with - ideally, a small file under\n" + " 1 kB or so. The cases must be stored as regular files directly in the\n" + " input directory.\n"); + + FATAL("No usable test cases in '%s'", in_dir); + + } + + last_path_time = 0; + queued_at_start = queued_paths; + +} + + +/* Helper function for load_extras. */ + +static int compare_extras_len(const void* p1, const void* p2) { + struct extra_data *e1 = (struct extra_data*)p1, + *e2 = (struct extra_data*)p2; + + return e1->len - e2->len; +} + +static int compare_extras_use_d(const void* p1, const void* p2) { + struct extra_data *e1 = (struct extra_data*)p1, + *e2 = (struct extra_data*)p2; + + return e2->hit_cnt - e1->hit_cnt; +} + + +/* Read extras from a file, sort by size. */ + +static void load_extras_file(u8* fname, u32* min_len, u32* max_len, + u32 dict_level) { + + FILE* f; + u8 buf[MAX_LINE]; + u8 *lptr; + u32 cur_line = 0; + + f = fopen(fname, "r"); + + if (!f) PFATAL("Unable to open '%s'", fname); + + while ((lptr = fgets(buf, MAX_LINE, f))) { + + u8 *rptr, *wptr; + u32 klen = 0; + + cur_line++; + + /* Trim on left and right. */ + + while (isspace(*lptr)) lptr++; + + rptr = lptr + strlen(lptr) - 1; + while (rptr >= lptr && isspace(*rptr)) rptr--; + rptr++; + *rptr = 0; + + /* Skip empty lines and comments. */ + + if (!*lptr || *lptr == '#') continue; + + /* All other lines must end with '"', which we can consume. */ + + rptr--; + + if (rptr < lptr || *rptr != '"') + FATAL("Malformed name=\"value\" pair in line %u.", cur_line); + + *rptr = 0; + + /* Skip alphanumerics and dashes (label). */ + + while (isalnum(*lptr) || *lptr == '_') lptr++; + + /* If @number follows, parse that. */ + + if (*lptr == '@') { + + lptr++; + if (atoi(lptr) > dict_level) continue; + while (isdigit(*lptr)) lptr++; + + } + + /* Skip whitespace and = signs. */ + + while (isspace(*lptr) || *lptr == '=') lptr++; + + /* Consume opening '"'. */ + + if (*lptr != '"') + FATAL("Malformed name=\"keyword\" pair in line %u.", cur_line); + + lptr++; + + if (!*lptr) FATAL("Empty keyword in line %u.", cur_line); + + /* Okay, let's allocate memory and copy data between "...", handling + \xNN escaping, \\, and \". */ + + extras = ck_realloc_block(extras, (extras_cnt + 1) * + sizeof(struct extra_data)); + + wptr = extras[extras_cnt].data = ck_alloc(rptr - lptr); + + while (*lptr) { + + char* hexdigits = "0123456789abcdef"; + + switch (*lptr) { + + case 1 ... 31: + case 128 ... 255: + FATAL("Non-printable characters in line %u.", cur_line); + + case '\\': + + lptr++; + + if (*lptr == '\\' || *lptr == '"') { + *(wptr++) = *(lptr++); + klen++; + break; + } + + if (*lptr != 'x' || !isxdigit(lptr[1]) || !isxdigit(lptr[2])) + FATAL("Invalid escaping (not \\xNN) in line %u.", cur_line); + + *(wptr++) = + ((strchr(hexdigits, tolower(lptr[1])) - hexdigits) << 4) | + (strchr(hexdigits, tolower(lptr[2])) - hexdigits); + + lptr += 3; + klen++; + + break; + + default: + + *(wptr++) = *(lptr++); + klen++; + + } + + } + + extras[extras_cnt].len = klen; + + if (extras[extras_cnt].len > MAX_DICT_FILE) + FATAL("Keyword too big in line %u (%s, limit is %s)", cur_line, + DMS(klen), DMS(MAX_DICT_FILE)); + + if (*min_len > klen) *min_len = klen; + if (*max_len < klen) *max_len = klen; + + extras_cnt++; + + } + + fclose(f); + +} + + +/* Read extras from the extras directory and sort them by size. */ + +static void load_extras(u8* dir) { + + DIR* d; + struct dirent* de; + u32 min_len = MAX_DICT_FILE, max_len = 0, dict_level = 0; + u8* x; + + /* If the name ends with @, extract level and continue. */ + + if ((x = strchr(dir, '@'))) { + + *x = 0; + dict_level = atoi(x + 1); + + } + + ACTF("Loading extra dictionary from '%s' (level %u)...", dir, dict_level); + + d = opendir(dir); + + if (!d) { + + if (errno == ENOTDIR) { + load_extras_file(dir, &min_len, &max_len, dict_level); + goto check_and_sort; + } + + PFATAL("Unable to open '%s'", dir); + + } + + if (x) FATAL("Dictionary levels not supported for directories."); + + while ((de = readdir(d))) { + + struct stat st; + u8* fn = alloc_printf("%s/%s", dir, de->d_name); + s32 fd; + + if (lstat(fn, &st) || access(fn, R_OK)) + PFATAL("Unable to access '%s'", fn); + + /* This also takes care of . and .. */ + if (!S_ISREG(st.st_mode) || !st.st_size) { + + ck_free(fn); + continue; + + } + + if (st.st_size > MAX_DICT_FILE) + FATAL("Extra '%s' is too big (%s, limit is %s)", fn, + DMS(st.st_size), DMS(MAX_DICT_FILE)); + + if (min_len > st.st_size) min_len = st.st_size; + if (max_len < st.st_size) max_len = st.st_size; + + extras = ck_realloc_block(extras, (extras_cnt + 1) * + sizeof(struct extra_data)); + + extras[extras_cnt].data = ck_alloc(st.st_size); + extras[extras_cnt].len = st.st_size; + + fd = open(fn, O_RDONLY); + + if (fd < 0) PFATAL("Unable to open '%s'", fn); + + ck_read(fd, extras[extras_cnt].data, st.st_size, fn); + + close(fd); + ck_free(fn); + + extras_cnt++; + + } + + closedir(d); + +check_and_sort: + + if (!extras_cnt) FATAL("No usable files in '%s'", dir); + + qsort(extras, extras_cnt, sizeof(struct extra_data), compare_extras_len); + + OKF("Loaded %u extra tokens, size range %s to %s.", extras_cnt, + DMS(min_len), DMS(max_len)); + + if (max_len > 32) + WARNF("Some tokens are relatively large (%s) - consider trimming.", + DMS(max_len)); + + if (extras_cnt > MAX_DET_EXTRAS) + WARNF("More than %u tokens - will use them probabilistically.", + MAX_DET_EXTRAS); + +} + + + + +/* Helper function for maybe_add_auto() */ + +static inline u8 memcmp_nocase(u8* m1, u8* m2, u32 len) { + + while (len--) if (tolower(*(m1++)) ^ tolower(*(m2++))) return 1; + return 0; + +} + + +/* Maybe add automatic extra. */ + +static void maybe_add_auto(u8* mem, u32 len) { + + u32 i; + + /* Allow users to specify that they don't want auto dictionaries. */ + + if (!MAX_AUTO_EXTRAS || !USE_AUTO_EXTRAS) return; + + /* Skip runs of identical bytes. */ + + for (i = 1; i < len; i++) + if (mem[0] ^ mem[i]) break; + + if (i == len) return; + + /* Reject builtin interesting values. */ + + if (len == 2) { + + i = sizeof(interesting_16) >> 1; + + while (i--) + if (*((u16*)mem) == interesting_16[i] || + *((u16*)mem) == SWAP16(interesting_16[i])) return; + + } + + if (len == 4) { + + i = sizeof(interesting_32) >> 2; + + while (i--) + if (*((u32*)mem) == interesting_32[i] || + *((u32*)mem) == SWAP32(interesting_32[i])) return; + + } + + /* Reject anything that matches existing extras. Do a case-insensitive + match. We optimize by exploiting the fact that extras[] are sorted + by size. */ + + for (i = 0; i < extras_cnt; i++) + if (extras[i].len >= len) break; + + for (; i < extras_cnt && extras[i].len == len; i++) + if (!memcmp_nocase(extras[i].data, mem, len)) return; + + /* Last but not least, check a_extras[] for matches. There are no + guarantees of a particular sort order. */ + + auto_changed = 1; + + for (i = 0; i < a_extras_cnt; i++) { + + if (a_extras[i].len == len && !memcmp_nocase(a_extras[i].data, mem, len)) { + + a_extras[i].hit_cnt++; + goto sort_a_extras; + + } + + } + + /* At this point, looks like we're dealing with a new entry. So, let's + append it if we have room. Otherwise, let's randomly evict some other + entry from the bottom half of the list. */ + + if (a_extras_cnt < MAX_AUTO_EXTRAS) { + + a_extras = ck_realloc_block(a_extras, (a_extras_cnt + 1) * + sizeof(struct extra_data)); + + a_extras[a_extras_cnt].data = ck_memdup(mem, len); + a_extras[a_extras_cnt].len = len; + a_extras_cnt++; + + } else { + + i = MAX_AUTO_EXTRAS / 2 + + UR((MAX_AUTO_EXTRAS + 1) / 2); + + ck_free(a_extras[i].data); + + a_extras[i].data = ck_memdup(mem, len); + a_extras[i].len = len; + a_extras[i].hit_cnt = 0; + + } + +sort_a_extras: + + /* First, sort all auto extras by use count, descending order. */ + + qsort(a_extras, a_extras_cnt, sizeof(struct extra_data), + compare_extras_use_d); + + /* Then, sort the top USE_AUTO_EXTRAS entries by size. */ + + qsort(a_extras, MIN(USE_AUTO_EXTRAS, a_extras_cnt), + sizeof(struct extra_data), compare_extras_len); + +} + + +/* Save automatically generated extras. */ + +static void save_auto(void) { + + u32 i; + + if (!auto_changed) return; + auto_changed = 0; + + for (i = 0; i < MIN(USE_AUTO_EXTRAS, a_extras_cnt); i++) { + + u8* fn = alloc_printf("%s/queue/.state/auto_extras/auto_%06u", out_dir, i); + s32 fd; + + fd = open(fn, O_WRONLY | O_CREAT | O_TRUNC, 0600); + + if (fd < 0) PFATAL("Unable to create '%s'", fn); + + ck_write(fd, a_extras[i].data, a_extras[i].len, fn); + + close(fd); + ck_free(fn); + + } + +} + + +/* Load automatically generated extras. */ + +static void load_auto(void) { + + u32 i; + + for (i = 0; i < USE_AUTO_EXTRAS; i++) { + + u8 tmp[MAX_AUTO_EXTRA + 1]; + u8* fn = alloc_printf("%s/.state/auto_extras/auto_%06u", in_dir, i); + s32 fd, len; + + fd = open(fn, O_RDONLY, 0600); + + if (fd < 0) { + + if (errno != ENOENT) PFATAL("Unable to open '%s'", fn); + ck_free(fn); + break; + + } + + /* We read one byte more to cheaply detect tokens that are too + long (and skip them). */ + + len = read(fd, tmp, MAX_AUTO_EXTRA + 1); + + if (len < 0) PFATAL("Unable to read from '%s'", fn); + + if (len >= MIN_AUTO_EXTRA && len <= MAX_AUTO_EXTRA) + maybe_add_auto(tmp, len); + + close(fd); + ck_free(fn); + + } + + if (i) OKF("Loaded %u auto-discovered dictionary tokens.", i); + else OKF("No auto-generated dictionary tokens to reuse."); + +} + + +/* Destroy extras. */ + +static void destroy_extras(void) { + + u32 i; + + for (i = 0; i < extras_cnt; i++) + ck_free(extras[i].data); + + ck_free(extras); + + for (i = 0; i < a_extras_cnt; i++) + ck_free(a_extras[i].data); + + ck_free(a_extras); + +} + + +/* Spin up fork server (instrumented mode only). The idea is explained here: + + http://lcamtuf.blogspot.com/2014/10/fuzzing-binaries-without-execve.html + + In essence, the instrumentation allows us to skip execve(), and just keep + cloning a stopped child. So, we just execute once, and then send commands + through a pipe. The other part of this logic is in afl-as.h. */ + +EXP_ST void init_forkserver(char** argv) { + + static struct itimerval it; + int st_pipe[2], ctl_pipe[2]; + int status; + s32 rlen; + + ACTF("Spinning up the fork server..."); + + if (pipe(st_pipe) || pipe(ctl_pipe)) PFATAL("pipe() failed"); + + forksrv_pid = fork(); + + if (forksrv_pid < 0) PFATAL("fork() failed"); + + if (!forksrv_pid) { + + struct rlimit r; + + /* Umpf. On OpenBSD, the default fd limit for root users is set to + soft 128. Let's try to fix that... */ + + if (!getrlimit(RLIMIT_NOFILE, &r) && r.rlim_cur < FORKSRV_FD + 2) { + + r.rlim_cur = FORKSRV_FD + 2; + setrlimit(RLIMIT_NOFILE, &r); /* Ignore errors */ + + } + + if (mem_limit) { + + r.rlim_max = r.rlim_cur = ((rlim_t)mem_limit) << 20; + +#ifdef RLIMIT_AS + + setrlimit(RLIMIT_AS, &r); /* Ignore errors */ + +#else + + /* This takes care of OpenBSD, which doesn't have RLIMIT_AS, but + according to reliable sources, RLIMIT_DATA covers anonymous + maps - so we should be getting good protection against OOM bugs. */ + + setrlimit(RLIMIT_DATA, &r); /* Ignore errors */ + +#endif /* ^RLIMIT_AS */ + + + } + + /* Dumping cores is slow and can lead to anomalies if SIGKILL is delivered + before the dump is complete. */ + + r.rlim_max = r.rlim_cur = 0; + + setrlimit(RLIMIT_CORE, &r); /* Ignore errors */ + + /* Isolate the process and configure standard descriptors. If out_file is + specified, stdin is /dev/null; otherwise, out_fd is cloned instead. */ + + setsid(); + + dup2(dev_null_fd, 1); + dup2(dev_null_fd, 2); + + if (out_file) { + + dup2(dev_null_fd, 0); + + } else { + + dup2(out_fd, 0); + close(out_fd); + + } + + /* Set up control and status pipes, close the unneeded original fds. */ + + if (dup2(ctl_pipe[0], FORKSRV_FD) < 0) PFATAL("dup2() failed"); + if (dup2(st_pipe[1], FORKSRV_FD + 1) < 0) PFATAL("dup2() failed"); + + close(ctl_pipe[0]); + close(ctl_pipe[1]); + close(st_pipe[0]); + close(st_pipe[1]); + + close(out_dir_fd); + close(dev_null_fd); + close(dev_urandom_fd); + close(fileno(plot_file)); + + /* This should improve performance a bit, since it stops the linker from + doing extra work post-fork(). */ + + if (!getenv("LD_BIND_LAZY")) setenv("LD_BIND_NOW", "1", 0); + + /* Set sane defaults for ASAN if nothing else specified. */ + + setenv("ASAN_OPTIONS", "abort_on_error=1:" + "detect_leaks=0:" + "symbolize=0:" + "allocator_may_return_null=1", 0); + + /* MSAN is tricky, because it doesn't support abort_on_error=1 at this + point. So, we do this in a very hacky way. */ + + setenv("MSAN_OPTIONS", "exit_code=" STRINGIFY(MSAN_ERROR) ":" + "symbolize=0:" + "abort_on_error=1:" + "allocator_may_return_null=1:" + "msan_track_origins=0", 0); + + execv(target_path, argv); + + /* Use a distinctive bitmap signature to tell the parent about execv() + falling through. */ + + *(u32*)trace_bits = EXEC_FAIL_SIG; + exit(0); + + } + + /* Close the unneeded endpoints. */ + + close(ctl_pipe[0]); + close(st_pipe[1]); + + fsrv_ctl_fd = ctl_pipe[1]; + fsrv_st_fd = st_pipe[0]; + + /* Wait for the fork server to come up, but don't wait too long. */ + + it.it_value.tv_sec = ((exec_tmout * FORK_WAIT_MULT) / 1000); + it.it_value.tv_usec = ((exec_tmout * FORK_WAIT_MULT) % 1000) * 1000; + + setitimer(ITIMER_REAL, &it, NULL); + + rlen = read(fsrv_st_fd, &status, 4); + + it.it_value.tv_sec = 0; + it.it_value.tv_usec = 0; + + setitimer(ITIMER_REAL, &it, NULL); + + /* If we have a four-byte "hello" message from the server, we're all set. + Otherwise, try to figure out what went wrong. */ + + if (rlen == 4) { + OKF("All right - fork server is up."); + return; + } + + if (child_timed_out) + FATAL("Timeout while initializing fork server (adjusting -t may help)"); + + if (waitpid(forksrv_pid, &status, 0) <= 0) + PFATAL("waitpid() failed"); + + if (WIFSIGNALED(status)) { + + if (mem_limit && mem_limit < 500 && uses_asan) { + + SAYF("\n" cLRD "[-] " cRST + "Whoops, the target binary crashed suddenly, before receiving any input\n" + " from the fuzzer! Since it seems to be built with ASAN and you have a\n" + " restrictive memory limit configured, this is expected; please read\n" + " %s/notes_for_asan.txt for help.\n", doc_path); + + } else if (!mem_limit) { + + SAYF("\n" cLRD "[-] " cRST + "Whoops, the target binary crashed suddenly, before receiving any input\n" + " from the fuzzer! There are several probable explanations:\n\n" + + " - The binary is just buggy and explodes entirely on its own. If so, you\n" + " need to fix the underlying problem or find a better replacement.\n\n" + +#ifdef __APPLE__ + + " - On MacOS X, the semantics of fork() syscalls are non-standard and may\n" + " break afl-fuzz performance optimizations when running platform-specific\n" + " targets. To fix this, set AFL_NO_FORKSRV=1 in the environment.\n\n" + +#endif /* __APPLE__ */ + + " - Less likely, there is a horrible bug in the fuzzer. If other options\n" + " fail, poke for troubleshooting tips.\n"); + + } else { + + SAYF("\n" cLRD "[-] " cRST + "Whoops, the target binary crashed suddenly, before receiving any input\n" + " from the fuzzer! There are several probable explanations:\n\n" + + " - The current memory limit (%s) is too restrictive, causing the\n" + " target to hit an OOM condition in the dynamic linker. Try bumping up\n" + " the limit with the -m setting in the command line. A simple way confirm\n" + " this diagnosis would be:\n\n" + +#ifdef RLIMIT_AS + " ( ulimit -Sv $[%llu << 10]; /path/to/fuzzed_app )\n\n" +#else + " ( ulimit -Sd $[%llu << 10]; /path/to/fuzzed_app )\n\n" +#endif /* ^RLIMIT_AS */ + + " Tip: you can use http://jwilk.net/software/recidivm to quickly\n" + " estimate the required amount of virtual memory for the binary.\n\n" + + " - The binary is just buggy and explodes entirely on its own. If so, you\n" + " need to fix the underlying problem or find a better replacement.\n\n" + +#ifdef __APPLE__ + + " - On MacOS X, the semantics of fork() syscalls are non-standard and may\n" + " break afl-fuzz performance optimizations when running platform-specific\n" + " targets. To fix this, set AFL_NO_FORKSRV=1 in the environment.\n\n" + +#endif /* __APPLE__ */ + + " - Less likely, there is a horrible bug in the fuzzer. If other options\n" + " fail, poke for troubleshooting tips.\n", + DMS(mem_limit << 20), mem_limit - 1); + + } + + FATAL("Fork server crashed with signal %d", WTERMSIG(status)); + + } + + if (*(u32*)trace_bits == EXEC_FAIL_SIG) + FATAL("Unable to execute target application ('%s')", argv[0]); + + if (mem_limit && mem_limit < 500 && uses_asan) { + + SAYF("\n" cLRD "[-] " cRST + "Hmm, looks like the target binary terminated before we could complete a\n" + " handshake with the injected code. Since it seems to be built with ASAN and\n" + " you have a restrictive memory limit configured, this is expected; please\n" + " read %s/notes_for_asan.txt for help.\n", doc_path); + + } else if (!mem_limit) { + + SAYF("\n" cLRD "[-] " cRST + "Hmm, looks like the target binary terminated before we could complete a\n" + " handshake with the injected code. Perhaps there is a horrible bug in the\n" + " fuzzer. Poke for troubleshooting tips.\n"); + + } else { + + SAYF("\n" cLRD "[-] " cRST + "Hmm, looks like the target binary terminated before we could complete a\n" + " handshake with the injected code. There are %s probable explanations:\n\n" + + "%s" + " - The current memory limit (%s) is too restrictive, causing an OOM\n" + " fault in the dynamic linker. This can be fixed with the -m option. A\n" + " simple way to confirm the diagnosis may be:\n\n" + +#ifdef RLIMIT_AS + " ( ulimit -Sv $[%llu << 10]; /path/to/fuzzed_app )\n\n" +#else + " ( ulimit -Sd $[%llu << 10]; /path/to/fuzzed_app )\n\n" +#endif /* ^RLIMIT_AS */ + + " Tip: you can use http://jwilk.net/software/recidivm to quickly\n" + " estimate the required amount of virtual memory for the binary.\n\n" + + " - Less likely, there is a horrible bug in the fuzzer. If other options\n" + " fail, poke for troubleshooting tips.\n", + getenv(DEFER_ENV_VAR) ? "three" : "two", + getenv(DEFER_ENV_VAR) ? + " - You are using deferred forkserver, but __AFL_INIT() is never\n" + " reached before the program terminates.\n\n" : "", + DMS(mem_limit << 20), mem_limit - 1); + + } + + FATAL("Fork server handshake failed"); + +} + + +/* Execute target application, monitoring for timeouts. Return status + information. The called program will update trace_bits[]. */ + +static u8 run_target(char** argv, u32 timeout) { + + static struct itimerval it; + static u32 prev_timed_out = 0; + static u64 exec_ms = 0; + + int status = 0; + u32 tb4; + + child_timed_out = 0; + + /* After this memset, trace_bits[] are effectively volatile, so we + must prevent any earlier operations from venturing into that + territory. */ + + memset(trace_bits, 0, MAP_SIZE); + MEM_BARRIER(); + + /* If we're running in "dumb" mode, we can't rely on the fork server + logic compiled into the target program, so we will just keep calling + execve(). There is a bit of code duplication between here and + init_forkserver(), but c'est la vie. */ + + if (dumb_mode == 1 || no_forkserver) { + + child_pid = fork(); + + if (child_pid < 0) PFATAL("fork() failed"); + + if (!child_pid) { + + struct rlimit r; + + if (mem_limit) { + + r.rlim_max = r.rlim_cur = ((rlim_t)mem_limit) << 20; + +#ifdef RLIMIT_AS + + setrlimit(RLIMIT_AS, &r); /* Ignore errors */ + +#else + + setrlimit(RLIMIT_DATA, &r); /* Ignore errors */ + +#endif /* ^RLIMIT_AS */ + + } + + r.rlim_max = r.rlim_cur = 0; + + setrlimit(RLIMIT_CORE, &r); /* Ignore errors */ + + /* Isolate the process and configure standard descriptors. If out_file is + specified, stdin is /dev/null; otherwise, out_fd is cloned instead. */ + + setsid(); + + dup2(dev_null_fd, 1); + dup2(dev_null_fd, 2); + + if (out_file) { + + dup2(dev_null_fd, 0); + + } else { + + dup2(out_fd, 0); + close(out_fd); + + } + + /* On Linux, would be faster to use O_CLOEXEC. Maybe TODO. */ + + close(dev_null_fd); + close(out_dir_fd); + close(dev_urandom_fd); + close(fileno(plot_file)); + + /* Set sane defaults for ASAN if nothing else specified. */ + + setenv("ASAN_OPTIONS", "abort_on_error=1:" + "detect_leaks=0:" + "symbolize=0:" + "allocator_may_return_null=1", 0); + + setenv("MSAN_OPTIONS", "exit_code=" STRINGIFY(MSAN_ERROR) ":" + "symbolize=0:" + "msan_track_origins=0", 0); + + execv(target_path, argv); + + /* Use a distinctive bitmap value to tell the parent about execv() + falling through. */ + + *(u32*)trace_bits = EXEC_FAIL_SIG; + exit(0); + + } + + } else { + + s32 res; + + /* In non-dumb mode, we have the fork server up and running, so simply + tell it to have at it, and then read back PID. */ + + if ((res = write(fsrv_ctl_fd, &prev_timed_out, 4)) != 4) { + + if (stop_soon) return 0; + RPFATAL(res, "Unable to request new process from fork server (OOM?)"); + + } + + if ((res = read(fsrv_st_fd, &child_pid, 4)) != 4) { + + if (stop_soon) return 0; + RPFATAL(res, "Unable to request new process from fork server (OOM?)"); + + } + + if (child_pid <= 0) FATAL("Fork server is misbehaving (OOM?)"); + + } + + /* Configure timeout, as requested by user, then wait for child to terminate. */ + + it.it_value.tv_sec = (timeout / 1000); + it.it_value.tv_usec = (timeout % 1000) * 1000; + + setitimer(ITIMER_REAL, &it, NULL); + + /* The SIGALRM handler simply kills the child_pid and sets child_timed_out. */ + + if (dumb_mode == 1 || no_forkserver) { + + if (waitpid(child_pid, &status, 0) <= 0) PFATAL("waitpid() failed"); + + } else { + + s32 res; + + if ((res = read(fsrv_st_fd, &status, 4)) != 4) { + + if (stop_soon) return 0; + RPFATAL(res, "Unable to communicate with fork server (OOM?)"); + + } + + } + + if (!WIFSTOPPED(status)) child_pid = 0; + + getitimer(ITIMER_REAL, &it); + exec_ms = (u64) timeout - (it.it_value.tv_sec * 1000 + + it.it_value.tv_usec / 1000); + + it.it_value.tv_sec = 0; + it.it_value.tv_usec = 0; + + setitimer(ITIMER_REAL, &it, NULL); + + total_execs++; + + /* Any subsequent operations on trace_bits must not be moved by the + compiler below this point. Past this location, trace_bits[] behave + very normally and do not have to be treated as volatile. */ + + MEM_BARRIER(); + + tb4 = *(u32*)trace_bits; + +#ifdef WORD_SIZE_64 + classify_counts((u64*)trace_bits); +#else + classify_counts((u32*)trace_bits); +#endif /* ^WORD_SIZE_64 */ + + prev_timed_out = child_timed_out; + + /* Report outcome to caller. */ + + if (WIFSIGNALED(status) && !stop_soon) { + + kill_signal = WTERMSIG(status); + + if (child_timed_out && kill_signal == SIGKILL) return FAULT_TMOUT; + + return FAULT_CRASH; + + } + + /* A somewhat nasty hack for MSAN, which doesn't support abort_on_error and + must use a special exit code. */ + + if (uses_asan && WEXITSTATUS(status) == MSAN_ERROR) { + kill_signal = 0; + return FAULT_CRASH; + } + + if ((dumb_mode == 1 || no_forkserver) && tb4 == EXEC_FAIL_SIG) + return FAULT_ERROR; + + /* It makes sense to account for the slowest units only if the testcase was run + under the user defined timeout. */ + if (!(timeout > exec_tmout) && (slowest_exec_ms < exec_ms)) { + slowest_exec_ms = exec_ms; + } + + return FAULT_NONE; + +} + + +/* Write modified data to file for testing. If out_file is set, the old file + is unlinked and a new one is created. Otherwise, out_fd is rewound and + truncated. */ + +static void write_to_testcase(void* mem, u32 len) { + + s32 fd = out_fd; + + if (out_file) { + + unlink(out_file); /* Ignore errors. */ + + fd = open(out_file, O_WRONLY | O_CREAT | O_EXCL, 0600); + + if (fd < 0) PFATAL("Unable to create '%s'", out_file); + + } else lseek(fd, 0, SEEK_SET); + + ck_write(fd, mem, len, out_file); + + if (!out_file) { + + if (ftruncate(fd, len)) PFATAL("ftruncate() failed"); + lseek(fd, 0, SEEK_SET); + + } else close(fd); + +} + + +/* The same, but with an adjustable gap. Used for trimming. */ + +static void write_with_gap(void* mem, u32 len, u32 skip_at, u32 skip_len) { + + s32 fd = out_fd; + u32 tail_len = len - skip_at - skip_len; + + if (out_file) { + + unlink(out_file); /* Ignore errors. */ + + fd = open(out_file, O_WRONLY | O_CREAT | O_EXCL, 0600); + + if (fd < 0) PFATAL("Unable to create '%s'", out_file); + + } else lseek(fd, 0, SEEK_SET); + + if (skip_at) ck_write(fd, mem, skip_at, out_file); + + if (tail_len) ck_write(fd, mem + skip_at + skip_len, tail_len, out_file); + + if (!out_file) { + + if (ftruncate(fd, len - skip_len)) PFATAL("ftruncate() failed"); + lseek(fd, 0, SEEK_SET); + + } else close(fd); + +} + + +static void show_stats(void); + +/* Calibrate a new test case. This is done when processing the input directory + to warn about flaky or otherwise problematic test cases early on; and when + new paths are discovered to detect variable behavior and so on. */ + +static u8 calibrate_case(char** argv, struct queue_entry* q, u8* use_mem, + u32 handicap, u8 from_queue) { + + static u8 first_trace[MAP_SIZE]; + + u8 fault = 0, new_bits = 0, var_detected = 0, hnb = 0, + first_run = (q->exec_cksum == 0); + + u64 start_us, stop_us; + + s32 old_sc = stage_cur, old_sm = stage_max; + u32 use_tmout = exec_tmout; + u8* old_sn = stage_name; + + /* Be a bit more generous about timeouts when resuming sessions, or when + trying to calibrate already-added finds. This helps avoid trouble due + to intermittent latency. */ + + if (!from_queue || resuming_fuzz) + use_tmout = MAX(exec_tmout + CAL_TMOUT_ADD, + exec_tmout * CAL_TMOUT_PERC / 100); + + q->cal_failed++; + + stage_name = "calibration"; + stage_max = fast_cal ? 3 : CAL_CYCLES; + + /* Make sure the forkserver is up before we do anything, and let's not + count its spin-up time toward binary calibration. */ + + if (dumb_mode != 1 && !no_forkserver && !forksrv_pid) + init_forkserver(argv); + + if (q->exec_cksum) { + + memcpy(first_trace, trace_bits, MAP_SIZE); + hnb = has_new_bits(virgin_bits); + if (hnb > new_bits) new_bits = hnb; + + } + + start_us = get_cur_time_us(); + + for (stage_cur = 0; stage_cur < stage_max; stage_cur++) { + + u32 cksum; + + if (!first_run && !(stage_cur % stats_update_freq)) show_stats(); + + write_to_testcase(use_mem, q->len); + + fault = run_target(argv, use_tmout); + + /* stop_soon is set by the handler for Ctrl+C. When it's pressed, + we want to bail out quickly. */ + + if (stop_soon || fault != crash_mode) goto abort_calibration; + + if (!dumb_mode && !stage_cur && !count_bytes(trace_bits)) { + fault = FAULT_NOINST; + goto abort_calibration; + } + + cksum = hash32(trace_bits, MAP_SIZE, HASH_CONST); + + if (q->exec_cksum != cksum) { + + hnb = has_new_bits(virgin_bits); + if (hnb > new_bits) new_bits = hnb; + + if (q->exec_cksum) { + + u32 i; + + for (i = 0; i < MAP_SIZE; i++) { + + if (!var_bytes[i] && first_trace[i] != trace_bits[i]) { + + var_bytes[i] = 1; + stage_max = CAL_CYCLES_LONG; + + } + + } + + var_detected = 1; + + } else { + + q->exec_cksum = cksum; + memcpy(first_trace, trace_bits, MAP_SIZE); + + } + + } + + } + + stop_us = get_cur_time_us(); + + total_cal_us += stop_us - start_us; + total_cal_cycles += stage_max; + + /* OK, let's collect some stats about the performance of this test case. + This is used for fuzzing air time calculations in calculate_score(). */ + + q->exec_us = (stop_us - start_us) / stage_max; + q->bitmap_size = count_bytes(trace_bits); + q->handicap = handicap; + q->cal_failed = 0; + + total_bitmap_size += q->bitmap_size; + total_bitmap_entries++; + + update_bitmap_score(q); + + /* If this case didn't result in new output from the instrumentation, tell + parent. This is a non-critical problem, but something to warn the user + about. */ + + if (!dumb_mode && first_run && !fault && !new_bits) fault = FAULT_NOBITS; + +abort_calibration: + + if (new_bits == 2 && !q->has_new_cov) { + q->has_new_cov = 1; + queued_with_cov++; + } + + /* Mark variable paths. */ + + if (var_detected) { + + var_byte_count = count_bytes(var_bytes); + + if (!q->var_behavior) { + mark_as_variable(q); + queued_variable++; + } + + } + + stage_name = old_sn; + stage_cur = old_sc; + stage_max = old_sm; + + if (!first_run) show_stats(); + + return fault; + +} + + +/* Examine map coverage. Called once, for first test case. */ + +static void check_map_coverage(void) { + + u32 i; + + if (count_bytes(trace_bits) < 100) return; + + for (i = (1 << (MAP_SIZE_POW2 - 1)); i < MAP_SIZE; i++) + if (trace_bits[i]) return; + + WARNF("Recompile binary with newer version of afl to improve coverage!"); + +} + + +/* Perform dry run of all test cases to confirm that the app is working as + expected. This is done only for the initial inputs, and only once. */ + +static void perform_dry_run(char** argv) { + + struct queue_entry* q = queue; + u32 cal_failures = 0; + u8* skip_crashes = getenv("AFL_SKIP_CRASHES"); + + while (q) { + + u8* use_mem; + u8 res; + s32 fd; + + u8* fn = strrchr(q->fname, '/') + 1; + + ACTF("Attempting dry run with '%s'...", fn); + + fd = open(q->fname, O_RDONLY); + if (fd < 0) PFATAL("Unable to open '%s'", q->fname); + + use_mem = ck_alloc_nozero(q->len); + + if (read(fd, use_mem, q->len) != q->len) + FATAL("Short read from '%s'", q->fname); + + close(fd); + + res = calibrate_case(argv, q, use_mem, 0, 1); + ck_free(use_mem); + + if (stop_soon) return; + + if (res == crash_mode || res == FAULT_NOBITS) + SAYF(cGRA " len = %u, map size = %u, exec speed = %llu us\n" cRST, + q->len, q->bitmap_size, q->exec_us); + + switch (res) { + + case FAULT_NONE: + + if (q == queue) check_map_coverage(); + + if (crash_mode) FATAL("Test case '%s' does *NOT* crash", fn); + + break; + + case FAULT_TMOUT: + + if (timeout_given) { + + /* The -t nn+ syntax in the command line sets timeout_given to '2' and + instructs afl-fuzz to tolerate but skip queue entries that time + out. */ + + if (timeout_given > 1) { + WARNF("Test case results in a timeout (skipping)"); + q->cal_failed = CAL_CHANCES; + cal_failures++; + break; + } + + SAYF("\n" cLRD "[-] " cRST + "The program took more than %u ms to process one of the initial test cases.\n" + " Usually, the right thing to do is to relax the -t option - or to delete it\n" + " altogether and allow the fuzzer to auto-calibrate. That said, if you know\n" + " what you are doing and want to simply skip the unruly test cases, append\n" + " '+' at the end of the value passed to -t ('-t %u+').\n", exec_tmout, + exec_tmout); + + FATAL("Test case '%s' results in a timeout", fn); + + } else { + + SAYF("\n" cLRD "[-] " cRST + "The program took more than %u ms to process one of the initial test cases.\n" + " This is bad news; raising the limit with the -t option is possible, but\n" + " will probably make the fuzzing process extremely slow.\n\n" + + " If this test case is just a fluke, the other option is to just avoid it\n" + " altogether, and find one that is less of a CPU hog.\n", exec_tmout); + + FATAL("Test case '%s' results in a timeout", fn); + + } + + case FAULT_CRASH: + + if (crash_mode) break; + + if (skip_crashes) { + WARNF("Test case results in a crash (skipping)"); + q->cal_failed = CAL_CHANCES; + cal_failures++; + break; + } + + if (mem_limit) { + + SAYF("\n" cLRD "[-] " cRST + "Oops, the program crashed with one of the test cases provided. There are\n" + " several possible explanations:\n\n" + + " - The test case causes known crashes under normal working conditions. If\n" + " so, please remove it. The fuzzer should be seeded with interesting\n" + " inputs - but not ones that cause an outright crash.\n\n" + + " - The current memory limit (%s) is too low for this program, causing\n" + " it to die due to OOM when parsing valid files. To fix this, try\n" + " bumping it up with the -m setting in the command line. If in doubt,\n" + " try something along the lines of:\n\n" + +#ifdef RLIMIT_AS + " ( ulimit -Sv $[%llu << 10]; /path/to/binary [...] for troubleshooting tips.\n", + DMS(mem_limit << 20), mem_limit - 1, doc_path); + + } else { + + SAYF("\n" cLRD "[-] " cRST + "Oops, the program crashed with one of the test cases provided. There are\n" + " several possible explanations:\n\n" + + " - The test case causes known crashes under normal working conditions. If\n" + " so, please remove it. The fuzzer should be seeded with interesting\n" + " inputs - but not ones that cause an outright crash.\n\n" + +#ifdef __APPLE__ + + " - On MacOS X, the semantics of fork() syscalls are non-standard and may\n" + " break afl-fuzz performance optimizations when running platform-specific\n" + " binaries. To fix this, set AFL_NO_FORKSRV=1 in the environment.\n\n" + +#endif /* __APPLE__ */ + + " - Least likely, there is a horrible bug in the fuzzer. If other options\n" + " fail, poke for troubleshooting tips.\n"); + + } + + FATAL("Test case '%s' results in a crash", fn); + + case FAULT_ERROR: + + FATAL("Unable to execute target application ('%s')", argv[0]); + + case FAULT_NOINST: + + FATAL("No instrumentation detected"); + + case FAULT_NOBITS: + + useless_at_start++; + + if (!in_bitmap && !shuffle_queue) + WARNF("No new instrumentation output, test case may be useless."); + + break; + + } + + if (q->var_behavior) WARNF("Instrumentation output varies across runs."); + + q = q->next; + + } + + if (cal_failures) { + + if (cal_failures == queued_paths) + FATAL("All test cases time out%s, giving up!", + skip_crashes ? " or crash" : ""); + + WARNF("Skipped %u test cases (%0.02f%%) due to timeouts%s.", cal_failures, + ((double)cal_failures) * 100 / queued_paths, + skip_crashes ? " or crashes" : ""); + + if (cal_failures * 5 > queued_paths) + WARNF(cLRD "High percentage of rejected test cases, check settings!"); + + } + + OKF("All test cases processed."); + +} + + +/* Helper function: link() if possible, copy otherwise. */ + +static void link_or_copy(u8* old_path, u8* new_path) { + + s32 i = link(old_path, new_path); + s32 sfd, dfd; + u8* tmp; + + if (!i) return; + + sfd = open(old_path, O_RDONLY); + if (sfd < 0) PFATAL("Unable to open '%s'", old_path); + + dfd = open(new_path, O_WRONLY | O_CREAT | O_EXCL, 0600); + if (dfd < 0) PFATAL("Unable to create '%s'", new_path); + + tmp = ck_alloc(64 * 1024); + + while ((i = read(sfd, tmp, 64 * 1024)) > 0) + ck_write(dfd, tmp, i, new_path); + + if (i < 0) PFATAL("read() failed"); + + ck_free(tmp); + close(sfd); + close(dfd); + +} + + +static void nuke_resume_dir(void); + +/* Create hard links for input test cases in the output directory, choosing + good names and pivoting accordingly. */ + +static void pivot_inputs(void) { + + struct queue_entry* q = queue; + u32 id = 0; + + ACTF("Creating hard links for all input files..."); + + while (q) { + + u8 *nfn, *rsl = strrchr(q->fname, '/'); + u32 orig_id; + + if (!rsl) rsl = q->fname; else rsl++; + + /* If the original file name conforms to the syntax and the recorded + ID matches the one we'd assign, just use the original file name. + This is valuable for resuming fuzzing runs. */ + +#ifndef SIMPLE_FILES +# define CASE_PREFIX "id:" +#else +# define CASE_PREFIX "id_" +#endif /* ^!SIMPLE_FILES */ + + if (!strncmp(rsl, CASE_PREFIX, 3) && + sscanf(rsl + 3, "%06u", &orig_id) == 1 && orig_id == id) { + + u8* src_str; + u32 src_id; + + resuming_fuzz = 1; + nfn = alloc_printf("%s/queue/%s", out_dir, rsl); + + /* Since we're at it, let's also try to find parent and figure out the + appropriate depth for this entry. */ + + src_str = strchr(rsl + 3, ':'); + + if (src_str && sscanf(src_str + 1, "%06u", &src_id) == 1) { + + struct queue_entry* s = queue; + while (src_id-- && s) s = s->next; + if (s) q->depth = s->depth + 1; + + if (max_depth < q->depth) max_depth = q->depth; + + } + + } else { + + /* No dice - invent a new name, capturing the original one as a + substring. */ + +#ifndef SIMPLE_FILES + + u8* use_name = strstr(rsl, ",orig:"); + + if (use_name) use_name += 6; else use_name = rsl; + nfn = alloc_printf("%s/queue/id:%06u,orig:%s", out_dir, id, use_name); + +#else + + nfn = alloc_printf("%s/queue/id_%06u", out_dir, id); + +#endif /* ^!SIMPLE_FILES */ + + } + + /* Pivot to the new queue entry. */ + + link_or_copy(q->fname, nfn); + ck_free(q->fname); + q->fname = nfn; + + /* Make sure that the passed_det value carries over, too. */ + + if (q->passed_det) mark_as_det_done(q); + + q = q->next; + id++; + + } + + if (in_place_resume) nuke_resume_dir(); + +} + + +#ifndef SIMPLE_FILES + +/* Construct a file name for a new test case, capturing the operation + that led to its discovery. Uses a static buffer. */ + +static u8* describe_op(u8 hnb) { + + static u8 ret[256]; + + if (syncing_party) { + + sprintf(ret, "sync:%s,src:%06u", syncing_party, syncing_case); + + } else { + + sprintf(ret, "src:%06u", current_entry); + + if (splicing_with >= 0) + sprintf(ret + strlen(ret), "+%06u", splicing_with); + + sprintf(ret + strlen(ret), ",op:%s", stage_short); + + if (stage_cur_byte >= 0) { + + sprintf(ret + strlen(ret), ",pos:%u", stage_cur_byte); + + if (stage_val_type != STAGE_VAL_NONE) + sprintf(ret + strlen(ret), ",val:%s%+d", + (stage_val_type == STAGE_VAL_BE) ? "be:" : "", + stage_cur_val); + + } else sprintf(ret + strlen(ret), ",rep:%u", stage_cur_val); + + } + + if (hnb == 2) strcat(ret, ",+cov"); + + return ret; + +} + +#endif /* !SIMPLE_FILES */ + + +/* Write a message accompanying the crash directory :-) */ + +static void write_crash_readme(void) { + + u8* fn = alloc_printf("%s/crashes/README.txt", out_dir); + s32 fd; + FILE* f; + + fd = open(fn, O_WRONLY | O_CREAT | O_EXCL, 0600); + ck_free(fn); + + /* Do not die on errors here - that would be impolite. */ + + if (fd < 0) return; + + f = fdopen(fd, "w"); + + if (!f) { + close(fd); + return; + } + + fprintf(f, "Command line used to find this crash:\n\n" + + "%s\n\n" + + "If you can't reproduce a bug outside of afl-fuzz, be sure to set the same\n" + "memory limit. The limit used for this fuzzing session was %s.\n\n" + + "Need a tool to minimize test cases before investigating the crashes or sending\n" + "them to a vendor? Check out the afl-tmin that comes with the fuzzer!\n\n" + + "Found any cool bugs in open-source tools using afl-fuzz? If yes, please drop\n" + "me a mail at once the issues are fixed - I'd love to\n" + "add your finds to the gallery at:\n\n" + + " http://lcamtuf.coredump.cx/afl/\n\n" + + "Thanks :-)\n", + + orig_cmdline, DMS(mem_limit << 20)); /* ignore errors */ + + fclose(f); + +} + + +/* Check if the result of an execve() during routine fuzzing is interesting, + save or queue the input test case for further analysis if so. Returns 1 if + entry is saved, 0 otherwise. */ + +static u8 save_if_interesting(char** argv, void* mem, u32 len, u8 fault) { + + u8 *fn = ""; + u8 hnb; + s32 fd; + u8 keeping = 0, res; + + if (fault == crash_mode) { + + /* Keep only if there are new bits in the map, add to queue for + future fuzzing, etc. */ + + if (!(hnb = has_new_bits(virgin_bits))) { + if (crash_mode) total_crashes++; + return 0; + } + +#ifndef SIMPLE_FILES + + fn = alloc_printf("%s/queue/id:%06u,%s", out_dir, queued_paths, + describe_op(hnb)); + +#else + + fn = alloc_printf("%s/queue/id_%06u", out_dir, queued_paths); + +#endif /* ^!SIMPLE_FILES */ + + add_to_queue(fn, len, 0); + + if (hnb == 2) { + queue_top->has_new_cov = 1; + queued_with_cov++; + } + + queue_top->exec_cksum = hash32(trace_bits, MAP_SIZE, HASH_CONST); + + /* Try to calibrate inline; this also calls update_bitmap_score() when + successful. */ + + res = calibrate_case(argv, queue_top, mem, queue_cycle - 1, 0); + + if (res == FAULT_ERROR) + FATAL("Unable to execute target application"); + + fd = open(fn, O_WRONLY | O_CREAT | O_EXCL, 0600); + if (fd < 0) PFATAL("Unable to create '%s'", fn); + ck_write(fd, mem, len, fn); + close(fd); + + keeping = 1; + + } + + switch (fault) { + + case FAULT_TMOUT: + + /* Timeouts are not very interesting, but we're still obliged to keep + a handful of samples. We use the presence of new bits in the + hang-specific bitmap as a signal of uniqueness. In "dumb" mode, we + just keep everything. */ + + total_tmouts++; + + if (unique_hangs >= KEEP_UNIQUE_HANG) return keeping; + + if (!dumb_mode) { + +#ifdef WORD_SIZE_64 + simplify_trace((u64*)trace_bits); +#else + simplify_trace((u32*)trace_bits); +#endif /* ^WORD_SIZE_64 */ + + if (!has_new_bits(virgin_tmout)) return keeping; + + } + + unique_tmouts++; + + /* Before saving, we make sure that it's a genuine hang by re-running + the target with a more generous timeout (unless the default timeout + is already generous). */ + + if (exec_tmout < hang_tmout) { + + u8 new_fault; + write_to_testcase(mem, len); + new_fault = run_target(argv, hang_tmout); + + /* A corner case that one user reported bumping into: increasing the + timeout actually uncovers a crash. Make sure we don't discard it if + so. */ + + if (!stop_soon && new_fault == FAULT_CRASH) goto keep_as_crash; + + if (stop_soon || new_fault != FAULT_TMOUT) return keeping; + + } + +#ifndef SIMPLE_FILES + + fn = alloc_printf("%s/hangs/id:%06llu,%s", out_dir, + unique_hangs, describe_op(0)); + +#else + + fn = alloc_printf("%s/hangs/id_%06llu", out_dir, + unique_hangs); + +#endif /* ^!SIMPLE_FILES */ + + unique_hangs++; + + last_hang_time = get_cur_time(); + + break; + + case FAULT_CRASH: + +keep_as_crash: + + /* This is handled in a manner roughly similar to timeouts, + except for slightly different limits and no need to re-run test + cases. */ + + total_crashes++; + + if (unique_crashes >= KEEP_UNIQUE_CRASH) return keeping; + + if (!dumb_mode) { + +#ifdef WORD_SIZE_64 + simplify_trace((u64*)trace_bits); +#else + simplify_trace((u32*)trace_bits); +#endif /* ^WORD_SIZE_64 */ + + if (!has_new_bits(virgin_crash)) return keeping; + + } + + if (!unique_crashes) write_crash_readme(); + +#ifndef SIMPLE_FILES + + fn = alloc_printf("%s/crashes/id:%06llu,sig:%02u,%s", out_dir, + unique_crashes, kill_signal, describe_op(0)); + +#else + + fn = alloc_printf("%s/crashes/id_%06llu_%02u", out_dir, unique_crashes, + kill_signal); + +#endif /* ^!SIMPLE_FILES */ + + unique_crashes++; + + last_crash_time = get_cur_time(); + last_crash_execs = total_execs; + + break; + + case FAULT_ERROR: FATAL("Unable to execute target application"); + + default: return keeping; + + } + + /* If we're here, we apparently want to save the crash or hang + test case, too. */ + + fd = open(fn, O_WRONLY | O_CREAT | O_EXCL, 0600); + if (fd < 0) PFATAL("Unable to create '%s'", fn); + ck_write(fd, mem, len, fn); + close(fd); + + ck_free(fn); + + return keeping; + +} + + +/* When resuming, try to find the queue position to start from. This makes sense + only when resuming, and when we can find the original fuzzer_stats. */ + +static u32 find_start_position(void) { + + static u8 tmp[4096]; /* Ought to be enough for anybody. */ + + u8 *fn, *off; + s32 fd, i; + u32 ret; + + if (!resuming_fuzz) return 0; + + if (in_place_resume) fn = alloc_printf("%s/fuzzer_stats", out_dir); + else fn = alloc_printf("%s/../fuzzer_stats", in_dir); + + fd = open(fn, O_RDONLY); + ck_free(fn); + + if (fd < 0) return 0; + + i = read(fd, tmp, sizeof(tmp) - 1); (void)i; /* Ignore errors */ + close(fd); + + off = strstr(tmp, "cur_path : "); + if (!off) return 0; + + ret = atoi(off + 20); + if (ret >= queued_paths) ret = 0; + return ret; + +} + + +/* The same, but for timeouts. The idea is that when resuming sessions without + -t given, we don't want to keep auto-scaling the timeout over and over + again to prevent it from growing due to random flukes. */ + +static void find_timeout(void) { + + static u8 tmp[4096]; /* Ought to be enough for anybody. */ + + u8 *fn, *off; + s32 fd, i; + u32 ret; + + if (!resuming_fuzz) return; + + if (in_place_resume) fn = alloc_printf("%s/fuzzer_stats", out_dir); + else fn = alloc_printf("%s/../fuzzer_stats", in_dir); + + fd = open(fn, O_RDONLY); + ck_free(fn); + + if (fd < 0) return; + + i = read(fd, tmp, sizeof(tmp) - 1); (void)i; /* Ignore errors */ + close(fd); + + off = strstr(tmp, "exec_timeout : "); + if (!off) return; + + ret = atoi(off + 20); + if (ret <= 4) return; + + exec_tmout = ret; + timeout_given = 3; + +} + + +/* Update stats file for unattended monitoring. */ + +static void write_stats_file(double bitmap_cvg, double stability, double eps) { + + static double last_bcvg, last_stab, last_eps; + static struct rusage usage; + + u8* fn = alloc_printf("%s/fuzzer_stats", out_dir); + s32 fd; + FILE* f; + + fd = open(fn, O_WRONLY | O_CREAT | O_TRUNC, 0600); + + if (fd < 0) PFATAL("Unable to create '%s'", fn); + + ck_free(fn); + + f = fdopen(fd, "w"); + + if (!f) PFATAL("fdopen() failed"); + + /* Keep last values in case we're called from another context + where exec/sec stats and such are not readily available. */ + + if (!bitmap_cvg && !stability && !eps) { + bitmap_cvg = last_bcvg; + stability = last_stab; + eps = last_eps; + } else { + last_bcvg = bitmap_cvg; + last_stab = stability; + last_eps = eps; + } + + fprintf(f, "start_time : %llu\n" + "last_update : %llu\n" + "fuzzer_pid : %u\n" + "cycles_done : %llu\n" + "execs_done : %llu\n" + "execs_per_sec : %0.02f\n" + "paths_total : %u\n" + "paths_favored : %u\n" + "paths_found : %u\n" + "paths_imported : %u\n" + "max_depth : %u\n" + "cur_path : %u\n" /* Must match find_start_position() */ + "pending_favs : %u\n" + "pending_total : %u\n" + "variable_paths : %u\n" + "stability : %0.02f%%\n" + "bitmap_cvg : %0.02f%%\n" + "unique_crashes : %llu\n" + "unique_hangs : %llu\n" + "last_path : %llu\n" + "last_crash : %llu\n" + "last_hang : %llu\n" + "execs_since_crash : %llu\n" + "exec_timeout : %u\n" /* Must match find_timeout() */ + "afl_banner : %s\n" + "afl_version : " VERSION "\n" + "target_mode : %s%s%s%s%s%s%s\n" + "command_line : %s\n" + "slowest_exec_ms : %llu\n", + start_time / 1000, get_cur_time() / 1000, getpid(), + queue_cycle ? (queue_cycle - 1) : 0, total_execs, eps, + queued_paths, queued_favored, queued_discovered, queued_imported, + max_depth, current_entry, pending_favored, pending_not_fuzzed, + queued_variable, stability, bitmap_cvg, unique_crashes, + unique_hangs, last_path_time / 1000, last_crash_time / 1000, + last_hang_time / 1000, total_execs - last_crash_execs, + exec_tmout, use_banner, + qemu_mode ? "qemu " : "", dumb_mode ? " dumb " : "", + no_forkserver ? "no_forksrv " : "", crash_mode ? "crash " : "", + persistent_mode ? "persistent " : "", deferred_mode ? "deferred " : "", + (qemu_mode || dumb_mode || no_forkserver || crash_mode || + persistent_mode || deferred_mode) ? "" : "default", + orig_cmdline, slowest_exec_ms); + /* ignore errors */ + + /* Get rss value from the children + We must have killed the forkserver process and called waitpid + before calling getrusage */ + if (getrusage(RUSAGE_CHILDREN, &usage)) { + WARNF("getrusage failed"); + } else if (usage.ru_maxrss == 0) { + fprintf(f, "peak_rss_mb : not available while afl is running\n"); + } else { +#ifdef __APPLE__ + fprintf(f, "peak_rss_mb : %zu\n", usage.ru_maxrss >> 20); +#else + fprintf(f, "peak_rss_mb : %zu\n", usage.ru_maxrss >> 10); +#endif /* ^__APPLE__ */ + } + + fclose(f); + +} + + +/* Update the plot file if there is a reason to. */ + +static void maybe_update_plot_file(double bitmap_cvg, double eps) { + + static u32 prev_qp, prev_pf, prev_pnf, prev_ce, prev_md; + static u64 prev_qc, prev_uc, prev_uh; + + if (prev_qp == queued_paths && prev_pf == pending_favored && + prev_pnf == pending_not_fuzzed && prev_ce == current_entry && + prev_qc == queue_cycle && prev_uc == unique_crashes && + prev_uh == unique_hangs && prev_md == max_depth) return; + + prev_qp = queued_paths; + prev_pf = pending_favored; + prev_pnf = pending_not_fuzzed; + prev_ce = current_entry; + prev_qc = queue_cycle; + prev_uc = unique_crashes; + prev_uh = unique_hangs; + prev_md = max_depth; + + /* Fields in the file: + + unix_time, cycles_done, cur_path, paths_total, paths_not_fuzzed, + favored_not_fuzzed, unique_crashes, unique_hangs, max_depth, + execs_per_sec */ + + fprintf(plot_file, + "%llu, %llu, %u, %u, %u, %u, %0.02f%%, %llu, %llu, %u, %0.02f\n", + get_cur_time() / 1000, queue_cycle - 1, current_entry, queued_paths, + pending_not_fuzzed, pending_favored, bitmap_cvg, unique_crashes, + unique_hangs, max_depth, eps); /* ignore errors */ + + fflush(plot_file); + +} + + + +/* A helper function for maybe_delete_out_dir(), deleting all prefixed + files in a directory. */ + +static u8 delete_files(u8* path, u8* prefix) { + + DIR* d; + struct dirent* d_ent; + + d = opendir(path); + + if (!d) return 0; + + while ((d_ent = readdir(d))) { + + if (d_ent->d_name[0] != '.' && (!prefix || + !strncmp(d_ent->d_name, prefix, strlen(prefix)))) { + + u8* fname = alloc_printf("%s/%s", path, d_ent->d_name); + if (unlink(fname)) PFATAL("Unable to delete '%s'", fname); + ck_free(fname); + + } + + } + + closedir(d); + + return !!rmdir(path); + +} + + +/* Get the number of runnable processes, with some simple smoothing. */ + +static double get_runnable_processes(void) { + + static double res; + +#if defined(__APPLE__) || defined(__FreeBSD__) || defined (__OpenBSD__) + + /* I don't see any portable sysctl or so that would quickly give us the + number of runnable processes; the 1-minute load average can be a + semi-decent approximation, though. */ + + if (getloadavg(&res, 1) != 1) return 0; + +#else + + /* On Linux, /proc/stat is probably the best way; load averages are + computed in funny ways and sometimes don't reflect extremely short-lived + processes well. */ + + FILE* f = fopen("/proc/stat", "r"); + u8 tmp[1024]; + u32 val = 0; + + if (!f) return 0; + + while (fgets(tmp, sizeof(tmp), f)) { + + if (!strncmp(tmp, "procs_running ", 14) || + !strncmp(tmp, "procs_blocked ", 14)) val += atoi(tmp + 14); + + } + + fclose(f); + + if (!res) { + + res = val; + + } else { + + res = res * (1.0 - 1.0 / AVG_SMOOTHING) + + ((double)val) * (1.0 / AVG_SMOOTHING); + + } + +#endif /* ^(__APPLE__ || __FreeBSD__ || __OpenBSD__) */ + + return res; + +} + + +/* Delete the temporary directory used for in-place session resume. */ + +static void nuke_resume_dir(void) { + + u8* fn; + + fn = alloc_printf("%s/_resume/.state/deterministic_done", out_dir); + if (delete_files(fn, CASE_PREFIX)) goto dir_cleanup_failed; + ck_free(fn); + + fn = alloc_printf("%s/_resume/.state/auto_extras", out_dir); + if (delete_files(fn, "auto_")) goto dir_cleanup_failed; + ck_free(fn); + + fn = alloc_printf("%s/_resume/.state/redundant_edges", out_dir); + if (delete_files(fn, CASE_PREFIX)) goto dir_cleanup_failed; + ck_free(fn); + + fn = alloc_printf("%s/_resume/.state/variable_behavior", out_dir); + if (delete_files(fn, CASE_PREFIX)) goto dir_cleanup_failed; + ck_free(fn); + + fn = alloc_printf("%s/_resume/.state", out_dir); + if (rmdir(fn) && errno != ENOENT) goto dir_cleanup_failed; + ck_free(fn); + + fn = alloc_printf("%s/_resume", out_dir); + if (delete_files(fn, CASE_PREFIX)) goto dir_cleanup_failed; + ck_free(fn); + + return; + +dir_cleanup_failed: + + FATAL("_resume directory cleanup failed"); + +} + + +/* Delete fuzzer output directory if we recognize it as ours, if the fuzzer + is not currently running, and if the last run time isn't too great. */ + +static void maybe_delete_out_dir(void) { + + FILE* f; + u8 *fn = alloc_printf("%s/fuzzer_stats", out_dir); + + /* See if the output directory is locked. If yes, bail out. If not, + create a lock that will persist for the lifetime of the process + (this requires leaving the descriptor open).*/ + + out_dir_fd = open(out_dir, O_RDONLY); + if (out_dir_fd < 0) PFATAL("Unable to open '%s'", out_dir); + +#ifndef __sun + + if (flock(out_dir_fd, LOCK_EX | LOCK_NB) && errno == EWOULDBLOCK) { + + SAYF("\n" cLRD "[-] " cRST + "Looks like the job output directory is being actively used by another\n" + " instance of afl-fuzz. You will need to choose a different %s\n" + " or stop the other process first.\n", + sync_id ? "fuzzer ID" : "output location"); + + FATAL("Directory '%s' is in use", out_dir); + + } + +#endif /* !__sun */ + + f = fopen(fn, "r"); + + if (f) { + + u64 start_time, last_update; + + if (fscanf(f, "start_time : %llu\n" + "last_update : %llu\n", &start_time, &last_update) != 2) + FATAL("Malformed data in '%s'", fn); + + fclose(f); + + /* Let's see how much work is at stake. */ + + if (!in_place_resume && last_update - start_time > OUTPUT_GRACE * 60) { + + SAYF("\n" cLRD "[-] " cRST + "The job output directory already exists and contains the results of more\n" + " than %u minutes worth of fuzzing. To avoid data loss, afl-fuzz will *NOT*\n" + " automatically delete this data for you.\n\n" + + " If you wish to start a new session, remove or rename the directory manually,\n" + " or specify a different output location for this job. To resume the old\n" + " session, put '-' as the input directory in the command line ('-i -') and\n" + " try again.\n", OUTPUT_GRACE); + + FATAL("At-risk data found in '%s'", out_dir); + + } + + } + + ck_free(fn); + + /* The idea for in-place resume is pretty simple: we temporarily move the old + queue/ to a new location that gets deleted once import to the new queue/ + is finished. If _resume/ already exists, the current queue/ may be + incomplete due to an earlier abort, so we want to use the old _resume/ + dir instead, and we let rename() fail silently. */ + + if (in_place_resume) { + + u8* orig_q = alloc_printf("%s/queue", out_dir); + + in_dir = alloc_printf("%s/_resume", out_dir); + + rename(orig_q, in_dir); /* Ignore errors */ + + OKF("Output directory exists, will attempt session resume."); + + ck_free(orig_q); + + } else { + + OKF("Output directory exists but deemed OK to reuse."); + + } + + ACTF("Deleting old session data..."); + + /* Okay, let's get the ball rolling! First, we need to get rid of the entries + in /.synced/.../id:*, if any are present. */ + + if (!in_place_resume) { + + fn = alloc_printf("%s/.synced", out_dir); + if (delete_files(fn, NULL)) goto dir_cleanup_failed; + ck_free(fn); + + } + + /* Next, we need to clean up /queue/.state/ subdirectories: */ + + fn = alloc_printf("%s/queue/.state/deterministic_done", out_dir); + if (delete_files(fn, CASE_PREFIX)) goto dir_cleanup_failed; + ck_free(fn); + + fn = alloc_printf("%s/queue/.state/auto_extras", out_dir); + if (delete_files(fn, "auto_")) goto dir_cleanup_failed; + ck_free(fn); + + fn = alloc_printf("%s/queue/.state/redundant_edges", out_dir); + if (delete_files(fn, CASE_PREFIX)) goto dir_cleanup_failed; + ck_free(fn); + + fn = alloc_printf("%s/queue/.state/variable_behavior", out_dir); + if (delete_files(fn, CASE_PREFIX)) goto dir_cleanup_failed; + ck_free(fn); + + /* Then, get rid of the .state subdirectory itself (should be empty by now) + and everything matching /queue/id:*. */ + + fn = alloc_printf("%s/queue/.state", out_dir); + if (rmdir(fn) && errno != ENOENT) goto dir_cleanup_failed; + ck_free(fn); + + fn = alloc_printf("%s/queue", out_dir); + if (delete_files(fn, CASE_PREFIX)) goto dir_cleanup_failed; + ck_free(fn); + + /* All right, let's do /crashes/id:* and /hangs/id:*. */ + + if (!in_place_resume) { + + fn = alloc_printf("%s/crashes/README.txt", out_dir); + unlink(fn); /* Ignore errors */ + ck_free(fn); + + } + + fn = alloc_printf("%s/crashes", out_dir); + + /* Make backup of the crashes directory if it's not empty and if we're + doing in-place resume. */ + + if (in_place_resume && rmdir(fn)) { + + time_t cur_t = time(0); + struct tm* t = localtime(&cur_t); + +#ifndef SIMPLE_FILES + + u8* nfn = alloc_printf("%s.%04u-%02u-%02u-%02u:%02u:%02u", fn, + t->tm_year + 1900, t->tm_mon + 1, t->tm_mday, + t->tm_hour, t->tm_min, t->tm_sec); + +#else + + u8* nfn = alloc_printf("%s_%04u%02u%02u%02u%02u%02u", fn, + t->tm_year + 1900, t->tm_mon + 1, t->tm_mday, + t->tm_hour, t->tm_min, t->tm_sec); + +#endif /* ^!SIMPLE_FILES */ + + rename(fn, nfn); /* Ignore errors. */ + ck_free(nfn); + + } + + if (delete_files(fn, CASE_PREFIX)) goto dir_cleanup_failed; + ck_free(fn); + + fn = alloc_printf("%s/hangs", out_dir); + + /* Backup hangs, too. */ + + if (in_place_resume && rmdir(fn)) { + + time_t cur_t = time(0); + struct tm* t = localtime(&cur_t); + +#ifndef SIMPLE_FILES + + u8* nfn = alloc_printf("%s.%04u-%02u-%02u-%02u:%02u:%02u", fn, + t->tm_year + 1900, t->tm_mon + 1, t->tm_mday, + t->tm_hour, t->tm_min, t->tm_sec); + +#else + + u8* nfn = alloc_printf("%s_%04u%02u%02u%02u%02u%02u", fn, + t->tm_year + 1900, t->tm_mon + 1, t->tm_mday, + t->tm_hour, t->tm_min, t->tm_sec); + +#endif /* ^!SIMPLE_FILES */ + + rename(fn, nfn); /* Ignore errors. */ + ck_free(nfn); + + } + + if (delete_files(fn, CASE_PREFIX)) goto dir_cleanup_failed; + ck_free(fn); + + /* And now, for some finishing touches. */ + + fn = alloc_printf("%s/.cur_input", out_dir); + if (unlink(fn) && errno != ENOENT) goto dir_cleanup_failed; + ck_free(fn); + + fn = alloc_printf("%s/fuzz_bitmap", out_dir); + if (unlink(fn) && errno != ENOENT) goto dir_cleanup_failed; + ck_free(fn); + + if (!in_place_resume) { + fn = alloc_printf("%s/fuzzer_stats", out_dir); + if (unlink(fn) && errno != ENOENT) goto dir_cleanup_failed; + ck_free(fn); + } + + fn = alloc_printf("%s/plot_data", out_dir); + if (unlink(fn) && errno != ENOENT) goto dir_cleanup_failed; + ck_free(fn); + + OKF("Output dir cleanup successful."); + + /* Wow... is that all? If yes, celebrate! */ + + return; + +dir_cleanup_failed: + + SAYF("\n" cLRD "[-] " cRST + "Whoops, the fuzzer tried to reuse your output directory, but bumped into\n" + " some files that shouldn't be there or that couldn't be removed - so it\n" + " decided to abort! This happened while processing this path:\n\n" + + " %s\n\n" + " Please examine and manually delete the files, or specify a different\n" + " output location for the tool.\n", fn); + + FATAL("Output directory cleanup failed"); + +} + + +static void check_term_size(void); + + +/* A spiffy retro stats screen! This is called every stats_update_freq + execve() calls, plus in several other circumstances. */ + +static void show_stats(void) { + + static u64 last_stats_ms, last_plot_ms, last_ms, last_execs; + static double avg_exec; + double t_byte_ratio, stab_ratio; + + u64 cur_ms; + u32 t_bytes, t_bits; + + u32 banner_len, banner_pad; + u8 tmp[256]; + + cur_ms = get_cur_time(); + + /* If not enough time has passed since last UI update, bail out. */ + + if (cur_ms - last_ms < 1000 / UI_TARGET_HZ) return; + + /* Check if we're past the 10 minute mark. */ + + if (cur_ms - start_time > 10 * 60 * 1000) run_over10m = 1; + + /* Calculate smoothed exec speed stats. */ + + if (!last_execs) { + + avg_exec = ((double)total_execs) * 1000 / (cur_ms - start_time); + + } else { + + double cur_avg = ((double)(total_execs - last_execs)) * 1000 / + (cur_ms - last_ms); + + /* If there is a dramatic (5x+) jump in speed, reset the indicator + more quickly. */ + + if (cur_avg * 5 < avg_exec || cur_avg / 5 > avg_exec) + avg_exec = cur_avg; + + avg_exec = avg_exec * (1.0 - 1.0 / AVG_SMOOTHING) + + cur_avg * (1.0 / AVG_SMOOTHING); + + } + + last_ms = cur_ms; + last_execs = total_execs; + + /* Tell the callers when to contact us (as measured in execs). */ + + stats_update_freq = avg_exec / (UI_TARGET_HZ * 10); + if (!stats_update_freq) stats_update_freq = 1; + + /* Do some bitmap stats. */ + + t_bytes = count_non_255_bytes(virgin_bits); + t_byte_ratio = ((double)t_bytes * 100) / MAP_SIZE; + + if (t_bytes) + stab_ratio = 100 - ((double)var_byte_count) * 100 / t_bytes; + else + stab_ratio = 100; + + /* Roughly every minute, update fuzzer stats and save auto tokens. */ + + if (cur_ms - last_stats_ms > STATS_UPDATE_SEC * 1000) { + + last_stats_ms = cur_ms; + write_stats_file(t_byte_ratio, stab_ratio, avg_exec); + save_auto(); + write_bitmap(); + + } + + /* Every now and then, write plot data. */ + + if (cur_ms - last_plot_ms > PLOT_UPDATE_SEC * 1000) { + + last_plot_ms = cur_ms; + maybe_update_plot_file(t_byte_ratio, avg_exec); + + } + + /* Honor AFL_EXIT_WHEN_DONE and AFL_BENCH_UNTIL_CRASH. */ + + if (!dumb_mode && cycles_wo_finds > 100 && !pending_not_fuzzed && + getenv("AFL_EXIT_WHEN_DONE")) stop_soon = 2; + + if (total_crashes && getenv("AFL_BENCH_UNTIL_CRASH")) stop_soon = 2; + + /* If we're not on TTY, bail out. */ + + if (not_on_tty) return; + + /* Compute some mildly useful bitmap stats. */ + + t_bits = (MAP_SIZE << 3) - count_bits(virgin_bits); + + /* Now, for the visuals... */ + + if (clear_screen) { + + SAYF(TERM_CLEAR CURSOR_HIDE); + clear_screen = 0; + + check_term_size(); + + } + + SAYF(TERM_HOME); + + if (term_too_small) { + + SAYF(cBRI "Your terminal is too small to display the UI.\n" + "Please resize terminal window to at least 80x25.\n" cRST); + + return; + + } + + /* Let's start by drawing a centered banner. */ + + banner_len = (crash_mode ? 24 : 22) + strlen(VERSION) + strlen(use_banner); + banner_pad = (80 - banner_len) / 2; + memset(tmp, ' ', banner_pad); + + sprintf(tmp + banner_pad, "%s " cLCY VERSION cLGN + " (%s)", crash_mode ? cPIN "peruvian were-rabbit" : + cYEL "american fuzzy lop", use_banner); + + SAYF("\n%s\n\n", tmp); + + /* "Handy" shortcuts for drawing boxes... */ + +#define bSTG bSTART cGRA +#define bH2 bH bH +#define bH5 bH2 bH2 bH +#define bH10 bH5 bH5 +#define bH20 bH10 bH10 +#define bH30 bH20 bH10 +#define SP5 " " +#define SP10 SP5 SP5 +#define SP20 SP10 SP10 + + /* Lord, forgive me this. */ + + SAYF(SET_G1 bSTG bLT bH bSTOP cCYA " process timing " bSTG bH30 bH5 bH2 bHB + bH bSTOP cCYA " overall results " bSTG bH5 bRT "\n"); + + if (dumb_mode) { + + strcpy(tmp, cRST); + + } else { + + u64 min_wo_finds = (cur_ms - last_path_time) / 1000 / 60; + + /* First queue cycle: don't stop now! */ + if (queue_cycle == 1 || min_wo_finds < 15) strcpy(tmp, cMGN); else + + /* Subsequent cycles, but we're still making finds. */ + if (cycles_wo_finds < 25 || min_wo_finds < 30) strcpy(tmp, cYEL); else + + /* No finds for a long time and no test cases to try. */ + if (cycles_wo_finds > 100 && !pending_not_fuzzed && min_wo_finds > 120) + strcpy(tmp, cLGN); + + /* Default: cautiously OK to stop? */ + else strcpy(tmp, cLBL); + + } + + SAYF(bV bSTOP " run time : " cRST "%-34s " bSTG bV bSTOP + " cycles done : %s%-5s " bSTG bV "\n", + DTD(cur_ms, start_time), tmp, DI(queue_cycle - 1)); + + /* We want to warn people about not seeing new paths after a full cycle, + except when resuming fuzzing or running in non-instrumented mode. */ + + if (!dumb_mode && (last_path_time || resuming_fuzz || queue_cycle == 1 || + in_bitmap || crash_mode)) { + + SAYF(bV bSTOP " last new path : " cRST "%-34s ", + DTD(cur_ms, last_path_time)); + + } else { + + if (dumb_mode) + + SAYF(bV bSTOP " last new path : " cPIN "n/a" cRST + " (non-instrumented mode) "); + + else + + SAYF(bV bSTOP " last new path : " cRST "none yet " cLRD + "(odd, check syntax!) "); + + } + + SAYF(bSTG bV bSTOP " total paths : " cRST "%-5s " bSTG bV "\n", + DI(queued_paths)); + + /* Highlight crashes in red if found, denote going over the KEEP_UNIQUE_CRASH + limit with a '+' appended to the count. */ + + sprintf(tmp, "%s%s", DI(unique_crashes), + (unique_crashes >= KEEP_UNIQUE_CRASH) ? "+" : ""); + + SAYF(bV bSTOP " last uniq crash : " cRST "%-34s " bSTG bV bSTOP + " uniq crashes : %s%-6s " bSTG bV "\n", + DTD(cur_ms, last_crash_time), unique_crashes ? cLRD : cRST, + tmp); + + sprintf(tmp, "%s%s", DI(unique_hangs), + (unique_hangs >= KEEP_UNIQUE_HANG) ? "+" : ""); + + SAYF(bV bSTOP " last uniq hang : " cRST "%-34s " bSTG bV bSTOP + " uniq hangs : " cRST "%-6s " bSTG bV "\n", + DTD(cur_ms, last_hang_time), tmp); + + SAYF(bVR bH bSTOP cCYA " cycle progress " bSTG bH20 bHB bH bSTOP cCYA + " map coverage " bSTG bH bHT bH20 bH2 bH bVL "\n"); + + /* This gets funny because we want to print several variable-length variables + together, but then cram them into a fixed-width field - so we need to + put them in a temporary buffer first. */ + + sprintf(tmp, "%s%s (%0.02f%%)", DI(current_entry), + queue_cur->favored ? "" : "*", + ((double)current_entry * 100) / queued_paths); + + SAYF(bV bSTOP " now processing : " cRST "%-17s " bSTG bV bSTOP, tmp); + + sprintf(tmp, "%0.02f%% / %0.02f%%", ((double)queue_cur->bitmap_size) * + 100 / MAP_SIZE, t_byte_ratio); + + SAYF(" map density : %s%-21s " bSTG bV "\n", t_byte_ratio > 70 ? cLRD : + ((t_bytes < 200 && !dumb_mode) ? cPIN : cRST), tmp); + + sprintf(tmp, "%s (%0.02f%%)", DI(cur_skipped_paths), + ((double)cur_skipped_paths * 100) / queued_paths); + + SAYF(bV bSTOP " paths timed out : " cRST "%-17s " bSTG bV, tmp); + + sprintf(tmp, "%0.02f bits/tuple", + t_bytes ? (((double)t_bits) / t_bytes) : 0); + + SAYF(bSTOP " count coverage : " cRST "%-21s " bSTG bV "\n", tmp); + + SAYF(bVR bH bSTOP cCYA " stage progress " bSTG bH20 bX bH bSTOP cCYA + " findings in depth " bSTG bH20 bVL "\n"); + + sprintf(tmp, "%s (%0.02f%%)", DI(queued_favored), + ((double)queued_favored) * 100 / queued_paths); + + /* Yeah... it's still going on... halp? */ + + SAYF(bV bSTOP " now trying : " cRST "%-21s " bSTG bV bSTOP + " favored paths : " cRST "%-22s " bSTG bV "\n", stage_name, tmp); + + if (!stage_max) { + + sprintf(tmp, "%s/-", DI(stage_cur)); + + } else { + + sprintf(tmp, "%s/%s (%0.02f%%)", DI(stage_cur), DI(stage_max), + ((double)stage_cur) * 100 / stage_max); + + } + + SAYF(bV bSTOP " stage execs : " cRST "%-21s " bSTG bV bSTOP, tmp); + + sprintf(tmp, "%s (%0.02f%%)", DI(queued_with_cov), + ((double)queued_with_cov) * 100 / queued_paths); + + SAYF(" new edges on : " cRST "%-22s " bSTG bV "\n", tmp); + + sprintf(tmp, "%s (%s%s unique)", DI(total_crashes), DI(unique_crashes), + (unique_crashes >= KEEP_UNIQUE_CRASH) ? "+" : ""); + + if (crash_mode) { + + SAYF(bV bSTOP " total execs : " cRST "%-21s " bSTG bV bSTOP + " new crashes : %s%-22s " bSTG bV "\n", DI(total_execs), + unique_crashes ? cLRD : cRST, tmp); + + } else { + + SAYF(bV bSTOP " total execs : " cRST "%-21s " bSTG bV bSTOP + " total crashes : %s%-22s " bSTG bV "\n", DI(total_execs), + unique_crashes ? cLRD : cRST, tmp); + + } + + /* Show a warning about slow execution. */ + + if (avg_exec < 100) { + + sprintf(tmp, "%s/sec (%s)", DF(avg_exec), avg_exec < 20 ? + "zzzz..." : "slow!"); + + SAYF(bV bSTOP " exec speed : " cLRD "%-21s ", tmp); + + } else { + + sprintf(tmp, "%s/sec", DF(avg_exec)); + SAYF(bV bSTOP " exec speed : " cRST "%-21s ", tmp); + + } + + sprintf(tmp, "%s (%s%s unique)", DI(total_tmouts), DI(unique_tmouts), + (unique_hangs >= KEEP_UNIQUE_HANG) ? "+" : ""); + + SAYF (bSTG bV bSTOP " total tmouts : " cRST "%-22s " bSTG bV "\n", tmp); + + /* Aaaalmost there... hold on! */ + + SAYF(bVR bH cCYA bSTOP " fuzzing strategy yields " bSTG bH10 bH bHT bH10 + bH5 bHB bH bSTOP cCYA " path geometry " bSTG bH5 bH2 bH bVL "\n"); + + if (skip_deterministic) { + + strcpy(tmp, "n/a, n/a, n/a"); + + } else { + + sprintf(tmp, "%s/%s, %s/%s, %s/%s", + DI(stage_finds[STAGE_FLIP1]), DI(stage_cycles[STAGE_FLIP1]), + DI(stage_finds[STAGE_FLIP2]), DI(stage_cycles[STAGE_FLIP2]), + DI(stage_finds[STAGE_FLIP4]), DI(stage_cycles[STAGE_FLIP4])); + + } + + SAYF(bV bSTOP " bit flips : " cRST "%-37s " bSTG bV bSTOP " levels : " + cRST "%-10s " bSTG bV "\n", tmp, DI(max_depth)); + + if (!skip_deterministic) + sprintf(tmp, "%s/%s, %s/%s, %s/%s", + DI(stage_finds[STAGE_FLIP8]), DI(stage_cycles[STAGE_FLIP8]), + DI(stage_finds[STAGE_FLIP16]), DI(stage_cycles[STAGE_FLIP16]), + DI(stage_finds[STAGE_FLIP32]), DI(stage_cycles[STAGE_FLIP32])); + + SAYF(bV bSTOP " byte flips : " cRST "%-37s " bSTG bV bSTOP " pending : " + cRST "%-10s " bSTG bV "\n", tmp, DI(pending_not_fuzzed)); + + if (!skip_deterministic) + sprintf(tmp, "%s/%s, %s/%s, %s/%s", + DI(stage_finds[STAGE_ARITH8]), DI(stage_cycles[STAGE_ARITH8]), + DI(stage_finds[STAGE_ARITH16]), DI(stage_cycles[STAGE_ARITH16]), + DI(stage_finds[STAGE_ARITH32]), DI(stage_cycles[STAGE_ARITH32])); + + SAYF(bV bSTOP " arithmetics : " cRST "%-37s " bSTG bV bSTOP " pend fav : " + cRST "%-10s " bSTG bV "\n", tmp, DI(pending_favored)); + + if (!skip_deterministic) + sprintf(tmp, "%s/%s, %s/%s, %s/%s", + DI(stage_finds[STAGE_INTEREST8]), DI(stage_cycles[STAGE_INTEREST8]), + DI(stage_finds[STAGE_INTEREST16]), DI(stage_cycles[STAGE_INTEREST16]), + DI(stage_finds[STAGE_INTEREST32]), DI(stage_cycles[STAGE_INTEREST32])); + + SAYF(bV bSTOP " known ints : " cRST "%-37s " bSTG bV bSTOP " own finds : " + cRST "%-10s " bSTG bV "\n", tmp, DI(queued_discovered)); + + if (!skip_deterministic) + sprintf(tmp, "%s/%s, %s/%s, %s/%s", + DI(stage_finds[STAGE_EXTRAS_UO]), DI(stage_cycles[STAGE_EXTRAS_UO]), + DI(stage_finds[STAGE_EXTRAS_UI]), DI(stage_cycles[STAGE_EXTRAS_UI]), + DI(stage_finds[STAGE_EXTRAS_AO]), DI(stage_cycles[STAGE_EXTRAS_AO])); + + SAYF(bV bSTOP " dictionary : " cRST "%-37s " bSTG bV bSTOP + " imported : " cRST "%-10s " bSTG bV "\n", tmp, + sync_id ? DI(queued_imported) : (u8*)"n/a"); + + sprintf(tmp, "%s/%s, %s/%s", + DI(stage_finds[STAGE_HAVOC]), DI(stage_cycles[STAGE_HAVOC]), + DI(stage_finds[STAGE_SPLICE]), DI(stage_cycles[STAGE_SPLICE])); + + SAYF(bV bSTOP " havoc : " cRST "%-37s " bSTG bV bSTOP, tmp); + + if (t_bytes) sprintf(tmp, "%0.02f%%", stab_ratio); + else strcpy(tmp, "n/a"); + + SAYF(" stability : %s%-10s " bSTG bV "\n", (stab_ratio < 85 && var_byte_count > 40) + ? cLRD : ((queued_variable && (!persistent_mode || var_byte_count > 20)) + ? cMGN : cRST), tmp); + + if (!bytes_trim_out) { + + sprintf(tmp, "n/a, "); + + } else { + + sprintf(tmp, "%0.02f%%/%s, ", + ((double)(bytes_trim_in - bytes_trim_out)) * 100 / bytes_trim_in, + DI(trim_execs)); + + } + + if (!blocks_eff_total) { + + u8 tmp2[128]; + + sprintf(tmp2, "n/a"); + strcat(tmp, tmp2); + + } else { + + u8 tmp2[128]; + + sprintf(tmp2, "%0.02f%%", + ((double)(blocks_eff_total - blocks_eff_select)) * 100 / + blocks_eff_total); + + strcat(tmp, tmp2); + + } + + SAYF(bV bSTOP " trim : " cRST "%-37s " bSTG bVR bH20 bH2 bH2 bRB "\n" + bLB bH30 bH20 bH2 bH bRB bSTOP cRST RESET_G1, tmp); + + /* Provide some CPU utilization stats. */ + + if (cpu_core_count) { + + double cur_runnable = get_runnable_processes(); + u32 cur_utilization = cur_runnable * 100 / cpu_core_count; + + u8* cpu_color = cCYA; + + /* If we could still run one or more processes, use green. */ + + if (cpu_core_count > 1 && cur_runnable + 1 <= cpu_core_count) + cpu_color = cLGN; + + /* If we're clearly oversubscribed, use red. */ + + if (!no_cpu_meter_red && cur_utilization >= 150) cpu_color = cLRD; + +#ifdef HAVE_AFFINITY + + if (cpu_aff >= 0) { + + SAYF(SP10 cGRA "[cpu%03u:%s%3u%%" cGRA "]\r" cRST, + MIN(cpu_aff, 999), cpu_color, + MIN(cur_utilization, 999)); + + } else { + + SAYF(SP10 cGRA " [cpu:%s%3u%%" cGRA "]\r" cRST, + cpu_color, MIN(cur_utilization, 999)); + + } + +#else + + SAYF(SP10 cGRA " [cpu:%s%3u%%" cGRA "]\r" cRST, + cpu_color, MIN(cur_utilization, 999)); + +#endif /* ^HAVE_AFFINITY */ + + } else SAYF("\r"); + + /* Hallelujah! */ + + fflush(0); + +} + + +/* Display quick statistics at the end of processing the input directory, + plus a bunch of warnings. Some calibration stuff also ended up here, + along with several hardcoded constants. Maybe clean up eventually. */ + +static void show_init_stats(void) { + + struct queue_entry* q = queue; + u32 min_bits = 0, max_bits = 0; + u64 min_us = 0, max_us = 0; + u64 avg_us = 0; + u32 max_len = 0; + + if (total_cal_cycles) avg_us = total_cal_us / total_cal_cycles; + + while (q) { + + if (!min_us || q->exec_us < min_us) min_us = q->exec_us; + if (q->exec_us > max_us) max_us = q->exec_us; + + if (!min_bits || q->bitmap_size < min_bits) min_bits = q->bitmap_size; + if (q->bitmap_size > max_bits) max_bits = q->bitmap_size; + + if (q->len > max_len) max_len = q->len; + + q = q->next; + + } + + SAYF("\n"); + + if (avg_us > (qemu_mode ? 50000 : 10000)) + WARNF(cLRD "The target binary is pretty slow! See %s/perf_tips.txt.", + doc_path); + + /* Let's keep things moving with slow binaries. */ + + if (avg_us > 50000) havoc_div = 10; /* 0-19 execs/sec */ + else if (avg_us > 20000) havoc_div = 5; /* 20-49 execs/sec */ + else if (avg_us > 10000) havoc_div = 2; /* 50-100 execs/sec */ + + if (!resuming_fuzz) { + + if (max_len > 50 * 1024) + WARNF(cLRD "Some test cases are huge (%s) - see %s/perf_tips.txt!", + DMS(max_len), doc_path); + else if (max_len > 10 * 1024) + WARNF("Some test cases are big (%s) - see %s/perf_tips.txt.", + DMS(max_len), doc_path); + + if (useless_at_start && !in_bitmap) + WARNF(cLRD "Some test cases look useless. Consider using a smaller set."); + + if (queued_paths > 100) + WARNF(cLRD "You probably have far too many input files! Consider trimming down."); + else if (queued_paths > 20) + WARNF("You have lots of input files; try starting small."); + + } + + OKF("Here are some useful stats:\n\n" + + cGRA " Test case count : " cRST "%u favored, %u variable, %u total\n" + cGRA " Bitmap range : " cRST "%u to %u bits (average: %0.02f bits)\n" + cGRA " Exec timing : " cRST "%s to %s us (average: %s us)\n", + queued_favored, queued_variable, queued_paths, min_bits, max_bits, + ((double)total_bitmap_size) / (total_bitmap_entries ? total_bitmap_entries : 1), + DI(min_us), DI(max_us), DI(avg_us)); + + if (!timeout_given) { + + /* Figure out the appropriate timeout. The basic idea is: 5x average or + 1x max, rounded up to EXEC_TM_ROUND ms and capped at 1 second. + + If the program is slow, the multiplier is lowered to 2x or 3x, because + random scheduler jitter is less likely to have any impact, and because + our patience is wearing thin =) */ + + if (avg_us > 50000) exec_tmout = avg_us * 2 / 1000; + else if (avg_us > 10000) exec_tmout = avg_us * 3 / 1000; + else exec_tmout = avg_us * 5 / 1000; + + exec_tmout = MAX(exec_tmout, max_us / 1000); + exec_tmout = (exec_tmout + EXEC_TM_ROUND) / EXEC_TM_ROUND * EXEC_TM_ROUND; + + if (exec_tmout > EXEC_TIMEOUT) exec_tmout = EXEC_TIMEOUT; + + ACTF("No -t option specified, so I'll use exec timeout of %u ms.", + exec_tmout); + + timeout_given = 1; + + } else if (timeout_given == 3) { + + ACTF("Applying timeout settings from resumed session (%u ms).", exec_tmout); + + } + + /* In dumb mode, re-running every timing out test case with a generous time + limit is very expensive, so let's select a more conservative default. */ + + if (dumb_mode && !getenv("AFL_HANG_TMOUT")) + hang_tmout = MIN(EXEC_TIMEOUT, exec_tmout * 2 + 100); + + OKF("All set and ready to roll!"); + +} + + +/* Find first power of two greater or equal to val (assuming val under + 2^31). */ + +static u32 next_p2(u32 val) { + + u32 ret = 1; + while (val > ret) ret <<= 1; + return ret; + +} + + +/* Trim all new test cases to save cycles when doing deterministic checks. The + trimmer uses power-of-two increments somewhere between 1/16 and 1/1024 of + file size, to keep the stage short and sweet. */ + +static u8 trim_case(char** argv, struct queue_entry* q, u8* in_buf) { + + static u8 tmp[64]; + static u8 clean_trace[MAP_SIZE]; + + u8 needs_write = 0, fault = 0; + u32 trim_exec = 0; + u32 remove_len; + u32 len_p2; + + /* Although the trimmer will be less useful when variable behavior is + detected, it will still work to some extent, so we don't check for + this. */ + + if (q->len < 5) return 0; + + stage_name = tmp; + bytes_trim_in += q->len; + + /* Select initial chunk len, starting with large steps. */ + + len_p2 = next_p2(q->len); + + remove_len = MAX(len_p2 / TRIM_START_STEPS, TRIM_MIN_BYTES); + + /* Continue until the number of steps gets too high or the stepover + gets too small. */ + + while (remove_len >= MAX(len_p2 / TRIM_END_STEPS, TRIM_MIN_BYTES)) { + + u32 remove_pos = remove_len; + + sprintf(tmp, "trim %s/%s", DI(remove_len), DI(remove_len)); + + stage_cur = 0; + stage_max = q->len / remove_len; + + while (remove_pos < q->len) { + + u32 trim_avail = MIN(remove_len, q->len - remove_pos); + u32 cksum; + + write_with_gap(in_buf, q->len, remove_pos, trim_avail); + + fault = run_target(argv, exec_tmout); + trim_execs++; + + if (stop_soon || fault == FAULT_ERROR) goto abort_trimming; + + /* Note that we don't keep track of crashes or hangs here; maybe TODO? */ + + cksum = hash32(trace_bits, MAP_SIZE, HASH_CONST); + + /* If the deletion had no impact on the trace, make it permanent. This + isn't perfect for variable-path inputs, but we're just making a + best-effort pass, so it's not a big deal if we end up with false + negatives every now and then. */ + + if (cksum == q->exec_cksum) { + + u32 move_tail = q->len - remove_pos - trim_avail; + + q->len -= trim_avail; + len_p2 = next_p2(q->len); + + memmove(in_buf + remove_pos, in_buf + remove_pos + trim_avail, + move_tail); + + /* Let's save a clean trace, which will be needed by + update_bitmap_score once we're done with the trimming stuff. */ + + if (!needs_write) { + + needs_write = 1; + memcpy(clean_trace, trace_bits, MAP_SIZE); + + } + + } else remove_pos += remove_len; + + /* Since this can be slow, update the screen every now and then. */ + + if (!(trim_exec++ % stats_update_freq)) show_stats(); + stage_cur++; + + } + + remove_len >>= 1; + + } + + /* If we have made changes to in_buf, we also need to update the on-disk + version of the test case. */ + + if (needs_write) { + + s32 fd; + + unlink(q->fname); /* ignore errors */ + + fd = open(q->fname, O_WRONLY | O_CREAT | O_EXCL, 0600); + + if (fd < 0) PFATAL("Unable to create '%s'", q->fname); + + ck_write(fd, in_buf, q->len, q->fname); + close(fd); + + memcpy(trace_bits, clean_trace, MAP_SIZE); + update_bitmap_score(q); + + } + +abort_trimming: + + bytes_trim_out += q->len; + return fault; + +} + + +/* Write a modified test case, run program, process results. Handle + error conditions, returning 1 if it's time to bail out. This is + a helper function for fuzz_one(). */ + +EXP_ST u8 common_fuzz_stuff(char** argv, u8* out_buf, u32 len) { + + u8 fault; + + if (post_handler) { + + out_buf = post_handler(out_buf, &len); + if (!out_buf || !len) return 0; + + } + + write_to_testcase(out_buf, len); + + fault = run_target(argv, exec_tmout); + + if (stop_soon) return 1; + + if (fault == FAULT_TMOUT) { + + if (subseq_tmouts++ > TMOUT_LIMIT) { + cur_skipped_paths++; + return 1; + } + + } else subseq_tmouts = 0; + + /* Users can hit us with SIGUSR1 to request the current input + to be abandoned. */ + + if (skip_requested) { + + skip_requested = 0; + cur_skipped_paths++; + return 1; + + } + + /* This handles FAULT_ERROR for us: */ + + queued_discovered += save_if_interesting(argv, out_buf, len, fault); + + if (!(stage_cur % stats_update_freq) || stage_cur + 1 == stage_max) + show_stats(); + + return 0; + +} + + +/* Helper to choose random block len for block operations in fuzz_one(). + Doesn't return zero, provided that max_len is > 0. */ + +static u32 choose_block_len(u32 limit) { + + u32 min_value, max_value; + u32 rlim = MIN(queue_cycle, 3); + + if (!run_over10m) rlim = 1; + + switch (UR(rlim)) { + + case 0: min_value = 1; + max_value = HAVOC_BLK_SMALL; + break; + + case 1: min_value = HAVOC_BLK_SMALL; + max_value = HAVOC_BLK_MEDIUM; + break; + + default: + + if (UR(10)) { + + min_value = HAVOC_BLK_MEDIUM; + max_value = HAVOC_BLK_LARGE; + + } else { + + min_value = HAVOC_BLK_LARGE; + max_value = HAVOC_BLK_XL; + + } + + } + + if (min_value >= limit) min_value = 1; + + return min_value + UR(MIN(max_value, limit) - min_value + 1); + +} + + +/* Calculate case desirability score to adjust the length of havoc fuzzing. + A helper function for fuzz_one(). Maybe some of these constants should + go into config.h. */ + +static u32 calculate_score(struct queue_entry* q) { + + u32 avg_exec_us = total_cal_us / total_cal_cycles; + u32 avg_bitmap_size = total_bitmap_size / total_bitmap_entries; + u32 perf_score = 100; + + /* Adjust score based on execution speed of this path, compared to the + global average. Multiplier ranges from 0.1x to 3x. Fast inputs are + less expensive to fuzz, so we're giving them more air time. */ + + if (q->exec_us * 0.1 > avg_exec_us) perf_score = 10; + else if (q->exec_us * 0.25 > avg_exec_us) perf_score = 25; + else if (q->exec_us * 0.5 > avg_exec_us) perf_score = 50; + else if (q->exec_us * 0.75 > avg_exec_us) perf_score = 75; + else if (q->exec_us * 4 < avg_exec_us) perf_score = 300; + else if (q->exec_us * 3 < avg_exec_us) perf_score = 200; + else if (q->exec_us * 2 < avg_exec_us) perf_score = 150; + + /* Adjust score based on bitmap size. The working theory is that better + coverage translates to better targets. Multiplier from 0.25x to 3x. */ + + if (q->bitmap_size * 0.3 > avg_bitmap_size) perf_score *= 3; + else if (q->bitmap_size * 0.5 > avg_bitmap_size) perf_score *= 2; + else if (q->bitmap_size * 0.75 > avg_bitmap_size) perf_score *= 1.5; + else if (q->bitmap_size * 3 < avg_bitmap_size) perf_score *= 0.25; + else if (q->bitmap_size * 2 < avg_bitmap_size) perf_score *= 0.5; + else if (q->bitmap_size * 1.5 < avg_bitmap_size) perf_score *= 0.75; + + /* Adjust score based on handicap. Handicap is proportional to how late + in the game we learned about this path. Latecomers are allowed to run + for a bit longer until they catch up with the rest. */ + + if (q->handicap >= 4) { + + perf_score *= 4; + q->handicap -= 4; + + } else if (q->handicap) { + + perf_score *= 2; + q->handicap--; + + } + + /* Final adjustment based on input depth, under the assumption that fuzzing + deeper test cases is more likely to reveal stuff that can't be + discovered with traditional fuzzers. */ + + switch (q->depth) { + + case 0 ... 3: break; + case 4 ... 7: perf_score *= 2; break; + case 8 ... 13: perf_score *= 3; break; + case 14 ... 25: perf_score *= 4; break; + default: perf_score *= 5; + + } + + /* Make sure that we don't go over limit. */ + + if (perf_score > HAVOC_MAX_MULT * 100) perf_score = HAVOC_MAX_MULT * 100; + + return perf_score; + +} + + +/* Helper function to see if a particular change (xor_val = old ^ new) could + be a product of deterministic bit flips with the lengths and stepovers + attempted by afl-fuzz. This is used to avoid dupes in some of the + deterministic fuzzing operations that follow bit flips. We also + return 1 if xor_val is zero, which implies that the old and attempted new + values are identical and the exec would be a waste of time. */ + +static u8 could_be_bitflip(u32 xor_val) { + + u32 sh = 0; + + if (!xor_val) return 1; + + /* Shift left until first bit set. */ + + while (!(xor_val & 1)) { sh++; xor_val >>= 1; } + + /* 1-, 2-, and 4-bit patterns are OK anywhere. */ + + if (xor_val == 1 || xor_val == 3 || xor_val == 15) return 1; + + /* 8-, 16-, and 32-bit patterns are OK only if shift factor is + divisible by 8, since that's the stepover for these ops. */ + + if (sh & 7) return 0; + + if (xor_val == 0xff || xor_val == 0xffff || xor_val == 0xffffffff) + return 1; + + return 0; + +} + + +/* Helper function to see if a particular value is reachable through + arithmetic operations. Used for similar purposes. */ + +static u8 could_be_arith(u32 old_val, u32 new_val, u8 blen) { + + u32 i, ov = 0, nv = 0, diffs = 0; + + if (old_val == new_val) return 1; + + /* See if one-byte adjustments to any byte could produce this result. */ + + for (i = 0; i < blen; i++) { + + u8 a = old_val >> (8 * i), + b = new_val >> (8 * i); + + if (a != b) { diffs++; ov = a; nv = b; } + + } + + /* If only one byte differs and the values are within range, return 1. */ + + if (diffs == 1) { + + if ((u8)(ov - nv) <= ARITH_MAX || + (u8)(nv - ov) <= ARITH_MAX) return 1; + + } + + if (blen == 1) return 0; + + /* See if two-byte adjustments to any byte would produce this result. */ + + diffs = 0; + + for (i = 0; i < blen / 2; i++) { + + u16 a = old_val >> (16 * i), + b = new_val >> (16 * i); + + if (a != b) { diffs++; ov = a; nv = b; } + + } + + /* If only one word differs and the values are within range, return 1. */ + + if (diffs == 1) { + + if ((u16)(ov - nv) <= ARITH_MAX || + (u16)(nv - ov) <= ARITH_MAX) return 1; + + ov = SWAP16(ov); nv = SWAP16(nv); + + if ((u16)(ov - nv) <= ARITH_MAX || + (u16)(nv - ov) <= ARITH_MAX) return 1; + + } + + /* Finally, let's do the same thing for dwords. */ + + if (blen == 4) { + + if ((u32)(old_val - new_val) <= ARITH_MAX || + (u32)(new_val - old_val) <= ARITH_MAX) return 1; + + new_val = SWAP32(new_val); + old_val = SWAP32(old_val); + + if ((u32)(old_val - new_val) <= ARITH_MAX || + (u32)(new_val - old_val) <= ARITH_MAX) return 1; + + } + + return 0; + +} + + +/* Last but not least, a similar helper to see if insertion of an + interesting integer is redundant given the insertions done for + shorter blen. The last param (check_le) is set if the caller + already executed LE insertion for current blen and wants to see + if BE variant passed in new_val is unique. */ + +static u8 could_be_interest(u32 old_val, u32 new_val, u8 blen, u8 check_le) { + + u32 i, j; + + if (old_val == new_val) return 1; + + /* See if one-byte insertions from interesting_8 over old_val could + produce new_val. */ + + for (i = 0; i < blen; i++) { + + for (j = 0; j < sizeof(interesting_8); j++) { + + u32 tval = (old_val & ~(0xff << (i * 8))) | + (((u8)interesting_8[j]) << (i * 8)); + + if (new_val == tval) return 1; + + } + + } + + /* Bail out unless we're also asked to examine two-byte LE insertions + as a preparation for BE attempts. */ + + if (blen == 2 && !check_le) return 0; + + /* See if two-byte insertions over old_val could give us new_val. */ + + for (i = 0; i < blen - 1; i++) { + + for (j = 0; j < sizeof(interesting_16) / 2; j++) { + + u32 tval = (old_val & ~(0xffff << (i * 8))) | + (((u16)interesting_16[j]) << (i * 8)); + + if (new_val == tval) return 1; + + /* Continue here only if blen > 2. */ + + if (blen > 2) { + + tval = (old_val & ~(0xffff << (i * 8))) | + (SWAP16(interesting_16[j]) << (i * 8)); + + if (new_val == tval) return 1; + + } + + } + + } + + if (blen == 4 && check_le) { + + /* See if four-byte insertions could produce the same result + (LE only). */ + + for (j = 0; j < sizeof(interesting_32) / 4; j++) + if (new_val == (u32)interesting_32[j]) return 1; + + } + + return 0; + +} + + +/* Take the current entry from the queue, fuzz it for a while. This + function is a tad too long... returns 0 if fuzzed successfully, 1 if + skipped or bailed out. */ + +static u8 fuzz_one(char** argv) { + + s32 len, fd, temp_len, i, j; + u8 *in_buf, *out_buf, *orig_in, *ex_tmp, *eff_map = 0; + u64 havoc_queued, orig_hit_cnt, new_hit_cnt; + u32 splice_cycle = 0, perf_score = 100, orig_perf, prev_cksum, eff_cnt = 1; + + u8 ret_val = 1, doing_det = 0; + + u8 a_collect[MAX_AUTO_EXTRA]; + u32 a_len = 0; + +#ifdef IGNORE_FINDS + + /* In IGNORE_FINDS mode, skip any entries that weren't in the + initial data set. */ + + if (queue_cur->depth > 1) return 1; + +#else + + if (pending_favored) { + + /* If we have any favored, non-fuzzed new arrivals in the queue, + possibly skip to them at the expense of already-fuzzed or non-favored + cases. */ + + if ((queue_cur->was_fuzzed || !queue_cur->favored) && + UR(100) < SKIP_TO_NEW_PROB) return 1; + + } else if (!dumb_mode && !queue_cur->favored && queued_paths > 10) { + + /* Otherwise, still possibly skip non-favored cases, albeit less often. + The odds of skipping stuff are higher for already-fuzzed inputs and + lower for never-fuzzed entries. */ + + if (queue_cycle > 1 && !queue_cur->was_fuzzed) { + + if (UR(100) < SKIP_NFAV_NEW_PROB) return 1; + + } else { + + if (UR(100) < SKIP_NFAV_OLD_PROB) return 1; + + } + + } + +#endif /* ^IGNORE_FINDS */ + + if (not_on_tty) { + ACTF("Fuzzing test case #%u (%u total, %llu uniq crashes found)...", + current_entry, queued_paths, unique_crashes); + fflush(stdout); + } + + /* Map the test case into memory. */ + + fd = open(queue_cur->fname, O_RDONLY); + + if (fd < 0) PFATAL("Unable to open '%s'", queue_cur->fname); + + len = queue_cur->len; + + orig_in = in_buf = mmap(0, len, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); + + if (orig_in == MAP_FAILED) PFATAL("Unable to mmap '%s'", queue_cur->fname); + + close(fd); + + /* We could mmap() out_buf as MAP_PRIVATE, but we end up clobbering every + single byte anyway, so it wouldn't give us any performance or memory usage + benefits. */ + + out_buf = ck_alloc_nozero(len); + + subseq_tmouts = 0; + + cur_depth = queue_cur->depth; + + /******************************************* + * CALIBRATION (only if failed earlier on) * + *******************************************/ + + if (queue_cur->cal_failed) { + + u8 res = FAULT_TMOUT; + + if (queue_cur->cal_failed < CAL_CHANCES) { + + /* Reset exec_cksum to tell calibrate_case to re-execute the testcase + avoiding the usage of an invalid trace_bits. + For more info: https://github.com/AFLplusplus/AFLplusplus/pull/425 */ + + queue_cur->exec_cksum = 0; + + res = calibrate_case(argv, queue_cur, in_buf, queue_cycle - 1, 0); + + if (res == FAULT_ERROR) + FATAL("Unable to execute target application"); + + } + + if (stop_soon || res != crash_mode) { + cur_skipped_paths++; + goto abandon_entry; + } + + } + + /************ + * TRIMMING * + ************/ + + if (!dumb_mode && !queue_cur->trim_done) { + + u8 res = trim_case(argv, queue_cur, in_buf); + + if (res == FAULT_ERROR) + FATAL("Unable to execute target application"); + + if (stop_soon) { + cur_skipped_paths++; + goto abandon_entry; + } + + /* Don't retry trimming, even if it failed. */ + + queue_cur->trim_done = 1; + + if (len != queue_cur->len) len = queue_cur->len; + + } + + memcpy(out_buf, in_buf, len); + + /********************* + * PERFORMANCE SCORE * + *********************/ + + orig_perf = perf_score = calculate_score(queue_cur); + + /* Skip right away if -d is given, if we have done deterministic fuzzing on + this entry ourselves (was_fuzzed), or if it has gone through deterministic + testing in earlier, resumed runs (passed_det). */ + + if (skip_deterministic || queue_cur->was_fuzzed || queue_cur->passed_det) + goto havoc_stage; + + /* Skip deterministic fuzzing if exec path checksum puts this out of scope + for this master instance. */ + + if (master_max && (queue_cur->exec_cksum % master_max) != master_id - 1) + goto havoc_stage; + + doing_det = 1; + + /********************************************* + * SIMPLE BITFLIP (+dictionary construction) * + *********************************************/ + +#define FLIP_BIT(_ar, _b) do { \ + u8* _arf = (u8*)(_ar); \ + u32 _bf = (_b); \ + _arf[(_bf) >> 3] ^= (128 >> ((_bf) & 7)); \ + } while (0) + + /* Single walking bit. */ + + stage_short = "flip1"; + stage_max = len << 3; + stage_name = "bitflip 1/1"; + + stage_val_type = STAGE_VAL_NONE; + + orig_hit_cnt = queued_paths + unique_crashes; + + prev_cksum = queue_cur->exec_cksum; + + for (stage_cur = 0; stage_cur < stage_max; stage_cur++) { + + stage_cur_byte = stage_cur >> 3; + + FLIP_BIT(out_buf, stage_cur); + + if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry; + + FLIP_BIT(out_buf, stage_cur); + + /* While flipping the least significant bit in every byte, pull of an extra + trick to detect possible syntax tokens. In essence, the idea is that if + you have a binary blob like this: + + xxxxxxxxIHDRxxxxxxxx + + ...and changing the leading and trailing bytes causes variable or no + changes in program flow, but touching any character in the "IHDR" string + always produces the same, distinctive path, it's highly likely that + "IHDR" is an atomically-checked magic value of special significance to + the fuzzed format. + + We do this here, rather than as a separate stage, because it's a nice + way to keep the operation approximately "free" (i.e., no extra execs). + + Empirically, performing the check when flipping the least significant bit + is advantageous, compared to doing it at the time of more disruptive + changes, where the program flow may be affected in more violent ways. + + The caveat is that we won't generate dictionaries in the -d mode or -S + mode - but that's probably a fair trade-off. + + This won't work particularly well with paths that exhibit variable + behavior, but fails gracefully, so we'll carry out the checks anyway. + + */ + + if (!dumb_mode && (stage_cur & 7) == 7) { + + u32 cksum = hash32(trace_bits, MAP_SIZE, HASH_CONST); + + if (stage_cur == stage_max - 1 && cksum == prev_cksum) { + + /* If at end of file and we are still collecting a string, grab the + final character and force output. */ + + if (a_len < MAX_AUTO_EXTRA) a_collect[a_len] = out_buf[stage_cur >> 3]; + a_len++; + + if (a_len >= MIN_AUTO_EXTRA && a_len <= MAX_AUTO_EXTRA) + maybe_add_auto(a_collect, a_len); + + } else if (cksum != prev_cksum) { + + /* Otherwise, if the checksum has changed, see if we have something + worthwhile queued up, and collect that if the answer is yes. */ + + if (a_len >= MIN_AUTO_EXTRA && a_len <= MAX_AUTO_EXTRA) + maybe_add_auto(a_collect, a_len); + + a_len = 0; + prev_cksum = cksum; + + } + + /* Continue collecting string, but only if the bit flip actually made + any difference - we don't want no-op tokens. */ + + if (cksum != queue_cur->exec_cksum) { + + if (a_len < MAX_AUTO_EXTRA) a_collect[a_len] = out_buf[stage_cur >> 3]; + a_len++; + + } + + } + + } + + new_hit_cnt = queued_paths + unique_crashes; + + stage_finds[STAGE_FLIP1] += new_hit_cnt - orig_hit_cnt; + stage_cycles[STAGE_FLIP1] += stage_max; + + /* Two walking bits. */ + + stage_name = "bitflip 2/1"; + stage_short = "flip2"; + stage_max = (len << 3) - 1; + + orig_hit_cnt = new_hit_cnt; + + for (stage_cur = 0; stage_cur < stage_max; stage_cur++) { + + stage_cur_byte = stage_cur >> 3; + + FLIP_BIT(out_buf, stage_cur); + FLIP_BIT(out_buf, stage_cur + 1); + + if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry; + + FLIP_BIT(out_buf, stage_cur); + FLIP_BIT(out_buf, stage_cur + 1); + + } + + new_hit_cnt = queued_paths + unique_crashes; + + stage_finds[STAGE_FLIP2] += new_hit_cnt - orig_hit_cnt; + stage_cycles[STAGE_FLIP2] += stage_max; + + /* Four walking bits. */ + + stage_name = "bitflip 4/1"; + stage_short = "flip4"; + stage_max = (len << 3) - 3; + + orig_hit_cnt = new_hit_cnt; + + for (stage_cur = 0; stage_cur < stage_max; stage_cur++) { + + stage_cur_byte = stage_cur >> 3; + + FLIP_BIT(out_buf, stage_cur); + FLIP_BIT(out_buf, stage_cur + 1); + FLIP_BIT(out_buf, stage_cur + 2); + FLIP_BIT(out_buf, stage_cur + 3); + + if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry; + + FLIP_BIT(out_buf, stage_cur); + FLIP_BIT(out_buf, stage_cur + 1); + FLIP_BIT(out_buf, stage_cur + 2); + FLIP_BIT(out_buf, stage_cur + 3); + + } + + new_hit_cnt = queued_paths + unique_crashes; + + stage_finds[STAGE_FLIP4] += new_hit_cnt - orig_hit_cnt; + stage_cycles[STAGE_FLIP4] += stage_max; + + /* Effector map setup. These macros calculate: + + EFF_APOS - position of a particular file offset in the map. + EFF_ALEN - length of a map with a particular number of bytes. + EFF_SPAN_ALEN - map span for a sequence of bytes. + + */ + +#define EFF_APOS(_p) ((_p) >> EFF_MAP_SCALE2) +#define EFF_REM(_x) ((_x) & ((1 << EFF_MAP_SCALE2) - 1)) +#define EFF_ALEN(_l) (EFF_APOS(_l) + !!EFF_REM(_l)) +#define EFF_SPAN_ALEN(_p, _l) (EFF_APOS((_p) + (_l) - 1) - EFF_APOS(_p) + 1) + + /* Initialize effector map for the next step (see comments below). Always + flag first and last byte as doing something. */ + + eff_map = ck_alloc(EFF_ALEN(len)); + eff_map[0] = 1; + + if (EFF_APOS(len - 1) != 0) { + eff_map[EFF_APOS(len - 1)] = 1; + eff_cnt++; + } + + /* Walking byte. */ + + stage_name = "bitflip 8/8"; + stage_short = "flip8"; + stage_max = len; + + orig_hit_cnt = new_hit_cnt; + + for (stage_cur = 0; stage_cur < stage_max; stage_cur++) { + + stage_cur_byte = stage_cur; + + out_buf[stage_cur] ^= 0xFF; + + if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry; + + /* We also use this stage to pull off a simple trick: we identify + bytes that seem to have no effect on the current execution path + even when fully flipped - and we skip them during more expensive + deterministic stages, such as arithmetics or known ints. */ + + if (!eff_map[EFF_APOS(stage_cur)]) { + + u32 cksum; + + /* If in dumb mode or if the file is very short, just flag everything + without wasting time on checksums. */ + + if (!dumb_mode && len >= EFF_MIN_LEN) + cksum = hash32(trace_bits, MAP_SIZE, HASH_CONST); + else + cksum = ~queue_cur->exec_cksum; + + if (cksum != queue_cur->exec_cksum) { + eff_map[EFF_APOS(stage_cur)] = 1; + eff_cnt++; + } + + } + + out_buf[stage_cur] ^= 0xFF; + + } + + /* If the effector map is more than EFF_MAX_PERC dense, just flag the + whole thing as worth fuzzing, since we wouldn't be saving much time + anyway. */ + + if (eff_cnt != EFF_ALEN(len) && + eff_cnt * 100 / EFF_ALEN(len) > EFF_MAX_PERC) { + + memset(eff_map, 1, EFF_ALEN(len)); + + blocks_eff_select += EFF_ALEN(len); + + } else { + + blocks_eff_select += eff_cnt; + + } + + blocks_eff_total += EFF_ALEN(len); + + new_hit_cnt = queued_paths + unique_crashes; + + stage_finds[STAGE_FLIP8] += new_hit_cnt - orig_hit_cnt; + stage_cycles[STAGE_FLIP8] += stage_max; + + /* Two walking bytes. */ + + if (len < 2) goto skip_bitflip; + + stage_name = "bitflip 16/8"; + stage_short = "flip16"; + stage_cur = 0; + stage_max = len - 1; + + orig_hit_cnt = new_hit_cnt; + + for (i = 0; i < len - 1; i++) { + + /* Let's consult the effector map... */ + + if (!eff_map[EFF_APOS(i)] && !eff_map[EFF_APOS(i + 1)]) { + stage_max--; + continue; + } + + stage_cur_byte = i; + + *(u16*)(out_buf + i) ^= 0xFFFF; + + if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry; + stage_cur++; + + *(u16*)(out_buf + i) ^= 0xFFFF; + + + } + + new_hit_cnt = queued_paths + unique_crashes; + + stage_finds[STAGE_FLIP16] += new_hit_cnt - orig_hit_cnt; + stage_cycles[STAGE_FLIP16] += stage_max; + + if (len < 4) goto skip_bitflip; + + /* Four walking bytes. */ + + stage_name = "bitflip 32/8"; + stage_short = "flip32"; + stage_cur = 0; + stage_max = len - 3; + + orig_hit_cnt = new_hit_cnt; + + for (i = 0; i < len - 3; i++) { + + /* Let's consult the effector map... */ + if (!eff_map[EFF_APOS(i)] && !eff_map[EFF_APOS(i + 1)] && + !eff_map[EFF_APOS(i + 2)] && !eff_map[EFF_APOS(i + 3)]) { + stage_max--; + continue; + } + + stage_cur_byte = i; + + *(u32*)(out_buf + i) ^= 0xFFFFFFFF; + + if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry; + stage_cur++; + + *(u32*)(out_buf + i) ^= 0xFFFFFFFF; + + } + + new_hit_cnt = queued_paths + unique_crashes; + + stage_finds[STAGE_FLIP32] += new_hit_cnt - orig_hit_cnt; + stage_cycles[STAGE_FLIP32] += stage_max; + +skip_bitflip: + + if (no_arith) goto skip_arith; + + /********************** + * ARITHMETIC INC/DEC * + **********************/ + + /* 8-bit arithmetics. */ + + stage_name = "arith 8/8"; + stage_short = "arith8"; + stage_cur = 0; + stage_max = 2 * len * ARITH_MAX; + + stage_val_type = STAGE_VAL_LE; + + orig_hit_cnt = new_hit_cnt; + + for (i = 0; i < len; i++) { + + u8 orig = out_buf[i]; + + /* Let's consult the effector map... */ + + if (!eff_map[EFF_APOS(i)]) { + stage_max -= 2 * ARITH_MAX; + continue; + } + + stage_cur_byte = i; + + for (j = 1; j <= ARITH_MAX; j++) { + + u8 r = orig ^ (orig + j); + + /* Do arithmetic operations only if the result couldn't be a product + of a bitflip. */ + + if (!could_be_bitflip(r)) { + + stage_cur_val = j; + out_buf[i] = orig + j; + + if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry; + stage_cur++; + + } else stage_max--; + + r = orig ^ (orig - j); + + if (!could_be_bitflip(r)) { + + stage_cur_val = -j; + out_buf[i] = orig - j; + + if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry; + stage_cur++; + + } else stage_max--; + + out_buf[i] = orig; + + } + + } + + new_hit_cnt = queued_paths + unique_crashes; + + stage_finds[STAGE_ARITH8] += new_hit_cnt - orig_hit_cnt; + stage_cycles[STAGE_ARITH8] += stage_max; + + /* 16-bit arithmetics, both endians. */ + + if (len < 2) goto skip_arith; + + stage_name = "arith 16/8"; + stage_short = "arith16"; + stage_cur = 0; + stage_max = 4 * (len - 1) * ARITH_MAX; + + orig_hit_cnt = new_hit_cnt; + + for (i = 0; i < len - 1; i++) { + + u16 orig = *(u16*)(out_buf + i); + + /* Let's consult the effector map... */ + + if (!eff_map[EFF_APOS(i)] && !eff_map[EFF_APOS(i + 1)]) { + stage_max -= 4 * ARITH_MAX; + continue; + } + + stage_cur_byte = i; + + for (j = 1; j <= ARITH_MAX; j++) { + + u16 r1 = orig ^ (orig + j), + r2 = orig ^ (orig - j), + r3 = orig ^ SWAP16(SWAP16(orig) + j), + r4 = orig ^ SWAP16(SWAP16(orig) - j); + + /* Try little endian addition and subtraction first. Do it only + if the operation would affect more than one byte (hence the + & 0xff overflow checks) and if it couldn't be a product of + a bitflip. */ + + stage_val_type = STAGE_VAL_LE; + + if ((orig & 0xff) + j > 0xff && !could_be_bitflip(r1)) { + + stage_cur_val = j; + *(u16*)(out_buf + i) = orig + j; + + if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry; + stage_cur++; + + } else stage_max--; + + if ((orig & 0xff) < j && !could_be_bitflip(r2)) { + + stage_cur_val = -j; + *(u16*)(out_buf + i) = orig - j; + + if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry; + stage_cur++; + + } else stage_max--; + + /* Big endian comes next. Same deal. */ + + stage_val_type = STAGE_VAL_BE; + + + if ((orig >> 8) + j > 0xff && !could_be_bitflip(r3)) { + + stage_cur_val = j; + *(u16*)(out_buf + i) = SWAP16(SWAP16(orig) + j); + + if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry; + stage_cur++; + + } else stage_max--; + + if ((orig >> 8) < j && !could_be_bitflip(r4)) { + + stage_cur_val = -j; + *(u16*)(out_buf + i) = SWAP16(SWAP16(orig) - j); + + if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry; + stage_cur++; + + } else stage_max--; + + *(u16*)(out_buf + i) = orig; + + } + + } + + new_hit_cnt = queued_paths + unique_crashes; + + stage_finds[STAGE_ARITH16] += new_hit_cnt - orig_hit_cnt; + stage_cycles[STAGE_ARITH16] += stage_max; + + /* 32-bit arithmetics, both endians. */ + + if (len < 4) goto skip_arith; + + stage_name = "arith 32/8"; + stage_short = "arith32"; + stage_cur = 0; + stage_max = 4 * (len - 3) * ARITH_MAX; + + orig_hit_cnt = new_hit_cnt; + + for (i = 0; i < len - 3; i++) { + + u32 orig = *(u32*)(out_buf + i); + + /* Let's consult the effector map... */ + + if (!eff_map[EFF_APOS(i)] && !eff_map[EFF_APOS(i + 1)] && + !eff_map[EFF_APOS(i + 2)] && !eff_map[EFF_APOS(i + 3)]) { + stage_max -= 4 * ARITH_MAX; + continue; + } + + stage_cur_byte = i; + + for (j = 1; j <= ARITH_MAX; j++) { + + u32 r1 = orig ^ (orig + j), + r2 = orig ^ (orig - j), + r3 = orig ^ SWAP32(SWAP32(orig) + j), + r4 = orig ^ SWAP32(SWAP32(orig) - j); + + /* Little endian first. Same deal as with 16-bit: we only want to + try if the operation would have effect on more than two bytes. */ + + stage_val_type = STAGE_VAL_LE; + + if ((orig & 0xffff) + j > 0xffff && !could_be_bitflip(r1)) { + + stage_cur_val = j; + *(u32*)(out_buf + i) = orig + j; + + if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry; + stage_cur++; + + } else stage_max--; + + if ((orig & 0xffff) < j && !could_be_bitflip(r2)) { + + stage_cur_val = -j; + *(u32*)(out_buf + i) = orig - j; + + if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry; + stage_cur++; + + } else stage_max--; + + /* Big endian next. */ + + stage_val_type = STAGE_VAL_BE; + + if ((SWAP32(orig) & 0xffff) + j > 0xffff && !could_be_bitflip(r3)) { + + stage_cur_val = j; + *(u32*)(out_buf + i) = SWAP32(SWAP32(orig) + j); + + if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry; + stage_cur++; + + } else stage_max--; + + if ((SWAP32(orig) & 0xffff) < j && !could_be_bitflip(r4)) { + + stage_cur_val = -j; + *(u32*)(out_buf + i) = SWAP32(SWAP32(orig) - j); + + if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry; + stage_cur++; + + } else stage_max--; + + *(u32*)(out_buf + i) = orig; + + } + + } + + new_hit_cnt = queued_paths + unique_crashes; + + stage_finds[STAGE_ARITH32] += new_hit_cnt - orig_hit_cnt; + stage_cycles[STAGE_ARITH32] += stage_max; + +skip_arith: + + /********************** + * INTERESTING VALUES * + **********************/ + + stage_name = "interest 8/8"; + stage_short = "int8"; + stage_cur = 0; + stage_max = len * sizeof(interesting_8); + + stage_val_type = STAGE_VAL_LE; + + orig_hit_cnt = new_hit_cnt; + + /* Setting 8-bit integers. */ + + for (i = 0; i < len; i++) { + + u8 orig = out_buf[i]; + + /* Let's consult the effector map... */ + + if (!eff_map[EFF_APOS(i)]) { + stage_max -= sizeof(interesting_8); + continue; + } + + stage_cur_byte = i; + + for (j = 0; j < sizeof(interesting_8); j++) { + + /* Skip if the value could be a product of bitflips or arithmetics. */ + + if (could_be_bitflip(orig ^ (u8)interesting_8[j]) || + could_be_arith(orig, (u8)interesting_8[j], 1)) { + stage_max--; + continue; + } + + stage_cur_val = interesting_8[j]; + out_buf[i] = interesting_8[j]; + + if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry; + + out_buf[i] = orig; + stage_cur++; + + } + + } + + new_hit_cnt = queued_paths + unique_crashes; + + stage_finds[STAGE_INTEREST8] += new_hit_cnt - orig_hit_cnt; + stage_cycles[STAGE_INTEREST8] += stage_max; + + /* Setting 16-bit integers, both endians. */ + + if (no_arith || len < 2) goto skip_interest; + + stage_name = "interest 16/8"; + stage_short = "int16"; + stage_cur = 0; + stage_max = 2 * (len - 1) * (sizeof(interesting_16) >> 1); + + orig_hit_cnt = new_hit_cnt; + + for (i = 0; i < len - 1; i++) { + + u16 orig = *(u16*)(out_buf + i); + + /* Let's consult the effector map... */ + + if (!eff_map[EFF_APOS(i)] && !eff_map[EFF_APOS(i + 1)]) { + stage_max -= sizeof(interesting_16); + continue; + } + + stage_cur_byte = i; + + for (j = 0; j < sizeof(interesting_16) / 2; j++) { + + stage_cur_val = interesting_16[j]; + + /* Skip if this could be a product of a bitflip, arithmetics, + or single-byte interesting value insertion. */ + + if (!could_be_bitflip(orig ^ (u16)interesting_16[j]) && + !could_be_arith(orig, (u16)interesting_16[j], 2) && + !could_be_interest(orig, (u16)interesting_16[j], 2, 0)) { + + stage_val_type = STAGE_VAL_LE; + + *(u16*)(out_buf + i) = interesting_16[j]; + + if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry; + stage_cur++; + + } else stage_max--; + + if ((u16)interesting_16[j] != SWAP16(interesting_16[j]) && + !could_be_bitflip(orig ^ SWAP16(interesting_16[j])) && + !could_be_arith(orig, SWAP16(interesting_16[j]), 2) && + !could_be_interest(orig, SWAP16(interesting_16[j]), 2, 1)) { + + stage_val_type = STAGE_VAL_BE; + + *(u16*)(out_buf + i) = SWAP16(interesting_16[j]); + if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry; + stage_cur++; + + } else stage_max--; + + } + + *(u16*)(out_buf + i) = orig; + + } + + new_hit_cnt = queued_paths + unique_crashes; + + stage_finds[STAGE_INTEREST16] += new_hit_cnt - orig_hit_cnt; + stage_cycles[STAGE_INTEREST16] += stage_max; + + if (len < 4) goto skip_interest; + + /* Setting 32-bit integers, both endians. */ + + stage_name = "interest 32/8"; + stage_short = "int32"; + stage_cur = 0; + stage_max = 2 * (len - 3) * (sizeof(interesting_32) >> 2); + + orig_hit_cnt = new_hit_cnt; + + for (i = 0; i < len - 3; i++) { + + u32 orig = *(u32*)(out_buf + i); + + /* Let's consult the effector map... */ + + if (!eff_map[EFF_APOS(i)] && !eff_map[EFF_APOS(i + 1)] && + !eff_map[EFF_APOS(i + 2)] && !eff_map[EFF_APOS(i + 3)]) { + stage_max -= sizeof(interesting_32) >> 1; + continue; + } + + stage_cur_byte = i; + + for (j = 0; j < sizeof(interesting_32) / 4; j++) { + + stage_cur_val = interesting_32[j]; + + /* Skip if this could be a product of a bitflip, arithmetics, + or word interesting value insertion. */ + + if (!could_be_bitflip(orig ^ (u32)interesting_32[j]) && + !could_be_arith(orig, interesting_32[j], 4) && + !could_be_interest(orig, interesting_32[j], 4, 0)) { + + stage_val_type = STAGE_VAL_LE; + + *(u32*)(out_buf + i) = interesting_32[j]; + + if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry; + stage_cur++; + + } else stage_max--; + + if ((u32)interesting_32[j] != SWAP32(interesting_32[j]) && + !could_be_bitflip(orig ^ SWAP32(interesting_32[j])) && + !could_be_arith(orig, SWAP32(interesting_32[j]), 4) && + !could_be_interest(orig, SWAP32(interesting_32[j]), 4, 1)) { + + stage_val_type = STAGE_VAL_BE; + + *(u32*)(out_buf + i) = SWAP32(interesting_32[j]); + if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry; + stage_cur++; + + } else stage_max--; + + } + + *(u32*)(out_buf + i) = orig; + + } + + new_hit_cnt = queued_paths + unique_crashes; + + stage_finds[STAGE_INTEREST32] += new_hit_cnt - orig_hit_cnt; + stage_cycles[STAGE_INTEREST32] += stage_max; + +skip_interest: + + /******************** + * DICTIONARY STUFF * + ********************/ + + if (!extras_cnt) goto skip_user_extras; + + /* Overwrite with user-supplied extras. */ + + stage_name = "user extras (over)"; + stage_short = "ext_UO"; + stage_cur = 0; + stage_max = extras_cnt * len; + + stage_val_type = STAGE_VAL_NONE; + + orig_hit_cnt = new_hit_cnt; + + for (i = 0; i < len; i++) { + + u32 last_len = 0; + + stage_cur_byte = i; + + /* Extras are sorted by size, from smallest to largest. This means + that we don't have to worry about restoring the buffer in + between writes at a particular offset determined by the outer + loop. */ + + for (j = 0; j < extras_cnt; j++) { + + /* Skip extras probabilistically if extras_cnt > MAX_DET_EXTRAS. Also + skip them if there's no room to insert the payload, if the token + is redundant, or if its entire span has no bytes set in the effector + map. */ + + if ((extras_cnt > MAX_DET_EXTRAS && UR(extras_cnt) >= MAX_DET_EXTRAS) || + extras[j].len > len - i || + !memcmp(extras[j].data, out_buf + i, extras[j].len) || + !memchr(eff_map + EFF_APOS(i), 1, EFF_SPAN_ALEN(i, extras[j].len))) { + + stage_max--; + continue; + + } + + last_len = extras[j].len; + memcpy(out_buf + i, extras[j].data, last_len); + + if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry; + + stage_cur++; + + } + + /* Restore all the clobbered memory. */ + memcpy(out_buf + i, in_buf + i, last_len); + + } + + new_hit_cnt = queued_paths + unique_crashes; + + stage_finds[STAGE_EXTRAS_UO] += new_hit_cnt - orig_hit_cnt; + stage_cycles[STAGE_EXTRAS_UO] += stage_max; + + /* Insertion of user-supplied extras. */ + + stage_name = "user extras (insert)"; + stage_short = "ext_UI"; + stage_cur = 0; + stage_max = extras_cnt * (len + 1); + + orig_hit_cnt = new_hit_cnt; + + ex_tmp = ck_alloc(len + MAX_DICT_FILE); + + for (i = 0; i <= len; i++) { + + stage_cur_byte = i; + + for (j = 0; j < extras_cnt; j++) { + + if (len + extras[j].len > MAX_FILE) { + stage_max--; + continue; + } + + /* Insert token */ + memcpy(ex_tmp + i, extras[j].data, extras[j].len); + + /* Copy tail */ + memcpy(ex_tmp + i + extras[j].len, out_buf + i, len - i); + + if (common_fuzz_stuff(argv, ex_tmp, len + extras[j].len)) { + ck_free(ex_tmp); + goto abandon_entry; + } + + stage_cur++; + + } + + /* Copy head */ + ex_tmp[i] = out_buf[i]; + + } + + ck_free(ex_tmp); + + new_hit_cnt = queued_paths + unique_crashes; + + stage_finds[STAGE_EXTRAS_UI] += new_hit_cnt - orig_hit_cnt; + stage_cycles[STAGE_EXTRAS_UI] += stage_max; + +skip_user_extras: + + if (!a_extras_cnt) goto skip_extras; + + stage_name = "auto extras (over)"; + stage_short = "ext_AO"; + stage_cur = 0; + stage_max = MIN(a_extras_cnt, USE_AUTO_EXTRAS) * len; + + stage_val_type = STAGE_VAL_NONE; + + orig_hit_cnt = new_hit_cnt; + + for (i = 0; i < len; i++) { + + u32 last_len = 0; + + stage_cur_byte = i; + + for (j = 0; j < MIN(a_extras_cnt, USE_AUTO_EXTRAS); j++) { + + /* See the comment in the earlier code; extras are sorted by size. */ + + if (a_extras[j].len > len - i || + !memcmp(a_extras[j].data, out_buf + i, a_extras[j].len) || + !memchr(eff_map + EFF_APOS(i), 1, EFF_SPAN_ALEN(i, a_extras[j].len))) { + + stage_max--; + continue; + + } + + last_len = a_extras[j].len; + memcpy(out_buf + i, a_extras[j].data, last_len); + + if (common_fuzz_stuff(argv, out_buf, len)) goto abandon_entry; + + stage_cur++; + + } + + /* Restore all the clobbered memory. */ + memcpy(out_buf + i, in_buf + i, last_len); + + } + + new_hit_cnt = queued_paths + unique_crashes; + + stage_finds[STAGE_EXTRAS_AO] += new_hit_cnt - orig_hit_cnt; + stage_cycles[STAGE_EXTRAS_AO] += stage_max; + +skip_extras: + + /* If we made this to here without jumping to havoc_stage or abandon_entry, + we're properly done with deterministic steps and can mark it as such + in the .state/ directory. */ + + if (!queue_cur->passed_det) mark_as_det_done(queue_cur); + + /**************** + * RANDOM HAVOC * + ****************/ + +havoc_stage: + + stage_cur_byte = -1; + + /* The havoc stage mutation code is also invoked when splicing files; if the + splice_cycle variable is set, generate different descriptions and such. */ + + if (!splice_cycle) { + + stage_name = "havoc"; + stage_short = "havoc"; + stage_max = (doing_det ? HAVOC_CYCLES_INIT : HAVOC_CYCLES) * + perf_score / havoc_div / 100; + + } else { + + static u8 tmp[32]; + + perf_score = orig_perf; + + sprintf(tmp, "splice %u", splice_cycle); + stage_name = tmp; + stage_short = "splice"; + stage_max = SPLICE_HAVOC * perf_score / havoc_div / 100; + + } + + if (stage_max < HAVOC_MIN) stage_max = HAVOC_MIN; + + temp_len = len; + + orig_hit_cnt = queued_paths + unique_crashes; + + havoc_queued = queued_paths; + + /* We essentially just do several thousand runs (depending on perf_score) + where we take the input file and make random stacked tweaks. */ + + for (stage_cur = 0; stage_cur < stage_max; stage_cur++) { + + u32 use_stacking = 1 << (1 + UR(HAVOC_STACK_POW2)); + + stage_cur_val = use_stacking; + + for (i = 0; i < use_stacking; i++) { + + switch (UR(15 + ((extras_cnt + a_extras_cnt) ? 2 : 0))) { + + case 0: + + /* Flip a single bit somewhere. Spooky! */ + + FLIP_BIT(out_buf, UR(temp_len << 3)); + break; + + case 1: + + /* Set byte to interesting value. */ + + out_buf[UR(temp_len)] = interesting_8[UR(sizeof(interesting_8))]; + break; + + case 2: + + /* Set word to interesting value, randomly choosing endian. */ + + if (temp_len < 2) break; + + if (UR(2)) { + + *(u16*)(out_buf + UR(temp_len - 1)) = + interesting_16[UR(sizeof(interesting_16) >> 1)]; + + } else { + + *(u16*)(out_buf + UR(temp_len - 1)) = SWAP16( + interesting_16[UR(sizeof(interesting_16) >> 1)]); + + } + + break; + + case 3: + + /* Set dword to interesting value, randomly choosing endian. */ + + if (temp_len < 4) break; + + if (UR(2)) { + + *(u32*)(out_buf + UR(temp_len - 3)) = + interesting_32[UR(sizeof(interesting_32) >> 2)]; + + } else { + + *(u32*)(out_buf + UR(temp_len - 3)) = SWAP32( + interesting_32[UR(sizeof(interesting_32) >> 2)]); + + } + + break; + + case 4: + + /* Randomly subtract from byte. */ + + out_buf[UR(temp_len)] -= 1 + UR(ARITH_MAX); + break; + + case 5: + + /* Randomly add to byte. */ + + out_buf[UR(temp_len)] += 1 + UR(ARITH_MAX); + break; + + case 6: + + /* Randomly subtract from word, random endian. */ + + if (temp_len < 2) break; + + if (UR(2)) { + + u32 pos = UR(temp_len - 1); + + *(u16*)(out_buf + pos) -= 1 + UR(ARITH_MAX); + + } else { + + u32 pos = UR(temp_len - 1); + u16 num = 1 + UR(ARITH_MAX); + + *(u16*)(out_buf + pos) = + SWAP16(SWAP16(*(u16*)(out_buf + pos)) - num); + + } + + break; + + case 7: + + /* Randomly add to word, random endian. */ + + if (temp_len < 2) break; + + if (UR(2)) { + + u32 pos = UR(temp_len - 1); + + *(u16*)(out_buf + pos) += 1 + UR(ARITH_MAX); + + } else { + + u32 pos = UR(temp_len - 1); + u16 num = 1 + UR(ARITH_MAX); + + *(u16*)(out_buf + pos) = + SWAP16(SWAP16(*(u16*)(out_buf + pos)) + num); + + } + + break; + + case 8: + + /* Randomly subtract from dword, random endian. */ + + if (temp_len < 4) break; + + if (UR(2)) { + + u32 pos = UR(temp_len - 3); + + *(u32*)(out_buf + pos) -= 1 + UR(ARITH_MAX); + + } else { + + u32 pos = UR(temp_len - 3); + u32 num = 1 + UR(ARITH_MAX); + + *(u32*)(out_buf + pos) = + SWAP32(SWAP32(*(u32*)(out_buf + pos)) - num); + + } + + break; + + case 9: + + /* Randomly add to dword, random endian. */ + + if (temp_len < 4) break; + + if (UR(2)) { + + u32 pos = UR(temp_len - 3); + + *(u32*)(out_buf + pos) += 1 + UR(ARITH_MAX); + + } else { + + u32 pos = UR(temp_len - 3); + u32 num = 1 + UR(ARITH_MAX); + + *(u32*)(out_buf + pos) = + SWAP32(SWAP32(*(u32*)(out_buf + pos)) + num); + + } + + break; + + case 10: + + /* Just set a random byte to a random value. Because, + why not. We use XOR with 1-255 to eliminate the + possibility of a no-op. */ + + out_buf[UR(temp_len)] ^= 1 + UR(255); + break; + + case 11 ... 12: { + + /* Delete bytes. We're making this a bit more likely + than insertion (the next option) in hopes of keeping + files reasonably small. */ + + u32 del_from, del_len; + + if (temp_len < 2) break; + + /* Don't delete too much. */ + + del_len = choose_block_len(temp_len - 1); + + del_from = UR(temp_len - del_len + 1); + + memmove(out_buf + del_from, out_buf + del_from + del_len, + temp_len - del_from - del_len); + + temp_len -= del_len; + + break; + + } + + case 13: + + if (temp_len + HAVOC_BLK_XL < MAX_FILE) { + + /* Clone bytes (75%) or insert a block of constant bytes (25%). */ + + u8 actually_clone = UR(4); + u32 clone_from, clone_to, clone_len; + u8* new_buf; + + if (actually_clone) { + + clone_len = choose_block_len(temp_len); + clone_from = UR(temp_len - clone_len + 1); + + } else { + + clone_len = choose_block_len(HAVOC_BLK_XL); + clone_from = 0; + + } + + clone_to = UR(temp_len); + + new_buf = ck_alloc_nozero(temp_len + clone_len); + + /* Head */ + + memcpy(new_buf, out_buf, clone_to); + + /* Inserted part */ + + if (actually_clone) + memcpy(new_buf + clone_to, out_buf + clone_from, clone_len); + else + memset(new_buf + clone_to, + UR(2) ? UR(256) : out_buf[UR(temp_len)], clone_len); + + /* Tail */ + memcpy(new_buf + clone_to + clone_len, out_buf + clone_to, + temp_len - clone_to); + + ck_free(out_buf); + out_buf = new_buf; + temp_len += clone_len; + + } + + break; + + case 14: { + + /* Overwrite bytes with a randomly selected chunk (75%) or fixed + bytes (25%). */ + + u32 copy_from, copy_to, copy_len; + + if (temp_len < 2) break; + + copy_len = choose_block_len(temp_len - 1); + + copy_from = UR(temp_len - copy_len + 1); + copy_to = UR(temp_len - copy_len + 1); + + if (UR(4)) { + + if (copy_from != copy_to) + memmove(out_buf + copy_to, out_buf + copy_from, copy_len); + + } else memset(out_buf + copy_to, + UR(2) ? UR(256) : out_buf[UR(temp_len)], copy_len); + + break; + + } + + /* Values 15 and 16 can be selected only if there are any extras + present in the dictionaries. */ + + case 15: { + + /* Overwrite bytes with an extra. */ + + if (!extras_cnt || (a_extras_cnt && UR(2))) { + + /* No user-specified extras or odds in our favor. Let's use an + auto-detected one. */ + + u32 use_extra = UR(a_extras_cnt); + u32 extra_len = a_extras[use_extra].len; + u32 insert_at; + + if (extra_len > temp_len) break; + + insert_at = UR(temp_len - extra_len + 1); + memcpy(out_buf + insert_at, a_extras[use_extra].data, extra_len); + + } else { + + /* No auto extras or odds in our favor. Use the dictionary. */ + + u32 use_extra = UR(extras_cnt); + u32 extra_len = extras[use_extra].len; + u32 insert_at; + + if (extra_len > temp_len) break; + + insert_at = UR(temp_len - extra_len + 1); + memcpy(out_buf + insert_at, extras[use_extra].data, extra_len); + + } + + break; + + } + + case 16: { + + u32 use_extra, extra_len, insert_at = UR(temp_len + 1); + u8* new_buf; + + /* Insert an extra. Do the same dice-rolling stuff as for the + previous case. */ + + if (!extras_cnt || (a_extras_cnt && UR(2))) { + + use_extra = UR(a_extras_cnt); + extra_len = a_extras[use_extra].len; + + if (temp_len + extra_len >= MAX_FILE) break; + + new_buf = ck_alloc_nozero(temp_len + extra_len); + + /* Head */ + memcpy(new_buf, out_buf, insert_at); + + /* Inserted part */ + memcpy(new_buf + insert_at, a_extras[use_extra].data, extra_len); + + } else { + + use_extra = UR(extras_cnt); + extra_len = extras[use_extra].len; + + if (temp_len + extra_len >= MAX_FILE) break; + + new_buf = ck_alloc_nozero(temp_len + extra_len); + + /* Head */ + memcpy(new_buf, out_buf, insert_at); + + /* Inserted part */ + memcpy(new_buf + insert_at, extras[use_extra].data, extra_len); + + } + + /* Tail */ + memcpy(new_buf + insert_at + extra_len, out_buf + insert_at, + temp_len - insert_at); + + ck_free(out_buf); + out_buf = new_buf; + temp_len += extra_len; + + break; + + } + + } + + } + + if (common_fuzz_stuff(argv, out_buf, temp_len)) + goto abandon_entry; + + /* out_buf might have been mangled a bit, so let's restore it to its + original size and shape. */ + + if (temp_len < len) out_buf = ck_realloc(out_buf, len); + temp_len = len; + memcpy(out_buf, in_buf, len); + + /* If we're finding new stuff, let's run for a bit longer, limits + permitting. */ + + if (queued_paths != havoc_queued) { + + if (perf_score <= HAVOC_MAX_MULT * 100) { + stage_max *= 2; + perf_score *= 2; + } + + havoc_queued = queued_paths; + + } + + } + + new_hit_cnt = queued_paths + unique_crashes; + + if (!splice_cycle) { + stage_finds[STAGE_HAVOC] += new_hit_cnt - orig_hit_cnt; + stage_cycles[STAGE_HAVOC] += stage_max; + } else { + stage_finds[STAGE_SPLICE] += new_hit_cnt - orig_hit_cnt; + stage_cycles[STAGE_SPLICE] += stage_max; + } + +#ifndef IGNORE_FINDS + + /************ + * SPLICING * + ************/ + + /* This is a last-resort strategy triggered by a full round with no findings. + It takes the current input file, randomly selects another input, and + splices them together at some offset, then relies on the havoc + code to mutate that blob. */ + +retry_splicing: + + if (use_splicing && splice_cycle++ < SPLICE_CYCLES && + queued_paths > 1 && queue_cur->len > 1) { + + struct queue_entry* target; + u32 tid, split_at; + u8* new_buf; + s32 f_diff, l_diff; + + /* First of all, if we've modified in_buf for havoc, let's clean that + up... */ + + if (in_buf != orig_in) { + ck_free(in_buf); + in_buf = orig_in; + len = queue_cur->len; + } + + /* Pick a random queue entry and seek to it. Don't splice with yourself. */ + + do { tid = UR(queued_paths); } while (tid == current_entry); + + splicing_with = tid; + target = queue; + + while (tid >= 100) { target = target->next_100; tid -= 100; } + while (tid--) target = target->next; + + /* Make sure that the target has a reasonable length. */ + + while (target && (target->len < 2 || target == queue_cur)) { + target = target->next; + splicing_with++; + } + + if (!target) goto retry_splicing; + + /* Read the testcase into a new buffer. */ + + fd = open(target->fname, O_RDONLY); + + if (fd < 0) PFATAL("Unable to open '%s'", target->fname); + + new_buf = ck_alloc_nozero(target->len); + + ck_read(fd, new_buf, target->len, target->fname); + + close(fd); + + /* Find a suitable splicing location, somewhere between the first and + the last differing byte. Bail out if the difference is just a single + byte or so. */ + + locate_diffs(in_buf, new_buf, MIN(len, target->len), &f_diff, &l_diff); + + if (f_diff < 0 || l_diff < 2 || f_diff == l_diff) { + ck_free(new_buf); + goto retry_splicing; + } + + /* Split somewhere between the first and last differing byte. */ + + split_at = f_diff + UR(l_diff - f_diff); + + /* Do the thing. */ + + len = target->len; + memcpy(new_buf, in_buf, split_at); + in_buf = new_buf; + + ck_free(out_buf); + out_buf = ck_alloc_nozero(len); + memcpy(out_buf, in_buf, len); + + goto havoc_stage; + + } + +#endif /* !IGNORE_FINDS */ + + ret_val = 0; + +abandon_entry: + + splicing_with = -1; + + /* Update pending_not_fuzzed count if we made it through the calibration + cycle and have not seen this entry before. */ + + if (!stop_soon && !queue_cur->cal_failed && !queue_cur->was_fuzzed) { + queue_cur->was_fuzzed = 1; + pending_not_fuzzed--; + if (queue_cur->favored) pending_favored--; + } + + munmap(orig_in, queue_cur->len); + + if (in_buf != orig_in) ck_free(in_buf); + ck_free(out_buf); + ck_free(eff_map); + + return ret_val; + +#undef FLIP_BIT + +} + + +/* Grab interesting test cases from other fuzzers. */ + +static void sync_fuzzers(char** argv) { + + DIR* sd; + struct dirent* sd_ent; + u32 sync_cnt = 0; + + sd = opendir(sync_dir); + if (!sd) PFATAL("Unable to open '%s'", sync_dir); + + stage_max = stage_cur = 0; + cur_depth = 0; + + /* Look at the entries created for every other fuzzer in the sync directory. */ + + while ((sd_ent = readdir(sd))) { + + static u8 stage_tmp[128]; + + DIR* qd; + struct dirent* qd_ent; + u8 *qd_path, *qd_synced_path; + u32 min_accept = 0, next_min_accept; + + s32 id_fd; + + /* Skip dot files and our own output directory. */ + + if (sd_ent->d_name[0] == '.' || !strcmp(sync_id, sd_ent->d_name)) continue; + + /* Skip anything that doesn't have a queue/ subdirectory. */ + + qd_path = alloc_printf("%s/%s/queue", sync_dir, sd_ent->d_name); + + if (!(qd = opendir(qd_path))) { + ck_free(qd_path); + continue; + } + + /* Retrieve the ID of the last seen test case. */ + + qd_synced_path = alloc_printf("%s/.synced/%s", out_dir, sd_ent->d_name); + + id_fd = open(qd_synced_path, O_RDWR | O_CREAT, 0600); + + if (id_fd < 0) PFATAL("Unable to create '%s'", qd_synced_path); + + if (read(id_fd, &min_accept, sizeof(u32)) > 0) + lseek(id_fd, 0, SEEK_SET); + + next_min_accept = min_accept; + + /* Show stats */ + + sprintf(stage_tmp, "sync %u", ++sync_cnt); + stage_name = stage_tmp; + stage_cur = 0; + stage_max = 0; + + /* For every file queued by this fuzzer, parse ID and see if we have looked at + it before; exec a test case if not. */ + + while ((qd_ent = readdir(qd))) { + + u8* path; + s32 fd; + struct stat st; + + if (qd_ent->d_name[0] == '.' || + sscanf(qd_ent->d_name, CASE_PREFIX "%06u", &syncing_case) != 1 || + syncing_case < min_accept) continue; + + /* OK, sounds like a new one. Let's give it a try. */ + + if (syncing_case >= next_min_accept) + next_min_accept = syncing_case + 1; + + path = alloc_printf("%s/%s", qd_path, qd_ent->d_name); + + /* Allow this to fail in case the other fuzzer is resuming or so... */ + + fd = open(path, O_RDONLY); + + if (fd < 0) { + ck_free(path); + continue; + } + + if (fstat(fd, &st)) PFATAL("fstat() failed"); + + /* Ignore zero-sized or oversized files. */ + + if (st.st_size && st.st_size <= MAX_FILE) { + + u8 fault; + u8* mem = mmap(0, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0); + + if (mem == MAP_FAILED) PFATAL("Unable to mmap '%s'", path); + + /* See what happens. We rely on save_if_interesting() to catch major + errors and save the test case. */ + + write_to_testcase(mem, st.st_size); + + fault = run_target(argv, exec_tmout); + + if (stop_soon) return; + + syncing_party = sd_ent->d_name; + queued_imported += save_if_interesting(argv, mem, st.st_size, fault); + syncing_party = 0; + + munmap(mem, st.st_size); + + if (!(stage_cur++ % stats_update_freq)) show_stats(); + + } + + ck_free(path); + close(fd); + + } + + ck_write(id_fd, &next_min_accept, sizeof(u32), qd_synced_path); + + close(id_fd); + closedir(qd); + ck_free(qd_path); + ck_free(qd_synced_path); + + } + + closedir(sd); + +} + + +/* Handle stop signal (Ctrl-C, etc). */ + +static void handle_stop_sig(int sig) { + + stop_soon = 1; + + if (child_pid > 0) kill(child_pid, SIGKILL); + if (forksrv_pid > 0) kill(forksrv_pid, SIGKILL); + +} + + +/* Handle skip request (SIGUSR1). */ + +static void handle_skipreq(int sig) { + + skip_requested = 1; + +} + +/* Handle timeout (SIGALRM). */ + +static void handle_timeout(int sig) { + + if (child_pid > 0) { + + child_timed_out = 1; + kill(child_pid, SIGKILL); + + } else if (child_pid == -1 && forksrv_pid > 0) { + + child_timed_out = 1; + kill(forksrv_pid, SIGKILL); + + } + +} + + +/* Do a PATH search and find target binary to see that it exists and + isn't a shell script - a common and painful mistake. We also check for + a valid ELF header and for evidence of AFL instrumentation. */ + +EXP_ST void check_binary(u8* fname) { + + u8* env_path = 0; + struct stat st; + + s32 fd; + u8* f_data; + u32 f_len = 0; + + ACTF("Validating target binary..."); + + if (strchr(fname, '/') || !(env_path = getenv("PATH"))) { + + target_path = ck_strdup(fname); + if (stat(target_path, &st) || !S_ISREG(st.st_mode) || + !(st.st_mode & 0111) || (f_len = st.st_size) < 4) + FATAL("Program '%s' not found or not executable", fname); + + } else { + + while (env_path) { + + u8 *cur_elem, *delim = strchr(env_path, ':'); + + if (delim) { + + cur_elem = ck_alloc(delim - env_path + 1); + memcpy(cur_elem, env_path, delim - env_path); + delim++; + + } else cur_elem = ck_strdup(env_path); + + env_path = delim; + + if (cur_elem[0]) + target_path = alloc_printf("%s/%s", cur_elem, fname); + else + target_path = ck_strdup(fname); + + ck_free(cur_elem); + + if (!stat(target_path, &st) && S_ISREG(st.st_mode) && + (st.st_mode & 0111) && (f_len = st.st_size) >= 4) break; + + ck_free(target_path); + target_path = 0; + + } + + if (!target_path) FATAL("Program '%s' not found or not executable", fname); + + } + + if (getenv("AFL_SKIP_BIN_CHECK")) return; + + /* Check for blatant user errors. */ + + if ((!strncmp(target_path, "/tmp/", 5) && !strchr(target_path + 5, '/')) || + (!strncmp(target_path, "/var/tmp/", 9) && !strchr(target_path + 9, '/'))) + FATAL("Please don't keep binaries in /tmp or /var/tmp"); + + fd = open(target_path, O_RDONLY); + + if (fd < 0) PFATAL("Unable to open '%s'", target_path); + + f_data = mmap(0, f_len, PROT_READ, MAP_PRIVATE, fd, 0); + + if (f_data == MAP_FAILED) PFATAL("Unable to mmap file '%s'", target_path); + + close(fd); + + if (f_data[0] == '#' && f_data[1] == '!') { + + SAYF("\n" cLRD "[-] " cRST + "Oops, the target binary looks like a shell script. Some build systems will\n" + " sometimes generate shell stubs for dynamically linked programs; try static\n" + " library mode (./configure --disable-shared) if that's the case.\n\n" + + " Another possible cause is that you are actually trying to use a shell\n" + " wrapper around the fuzzed component. Invoking shell can slow down the\n" + " fuzzing process by a factor of 20x or more; it's best to write the wrapper\n" + " in a compiled language instead.\n"); + + FATAL("Program '%s' is a shell script", target_path); + + } + +#ifndef __APPLE__ + + if (f_data[0] != 0x7f || memcmp(f_data + 1, "ELF", 3)) + FATAL("Program '%s' is not an ELF binary", target_path); + +#else + + if (f_data[0] != 0xCF || f_data[1] != 0xFA || f_data[2] != 0xED) + FATAL("Program '%s' is not a 64-bit Mach-O binary", target_path); + +#endif /* ^!__APPLE__ */ + + if (!qemu_mode && !dumb_mode && + !memmem(f_data, f_len, SHM_ENV_VAR, strlen(SHM_ENV_VAR) + 1)) { + + SAYF("\n" cLRD "[-] " cRST + "Looks like the target binary is not instrumented! The fuzzer depends on\n" + " compile-time instrumentation to isolate interesting test cases while\n" + " mutating the input data. For more information, and for tips on how to\n" + " instrument binaries, please see %s/README.\n\n" + + " When source code is not available, you may be able to leverage QEMU\n" + " mode support. Consult the README for tips on how to enable this.\n" + + " (It is also possible to use afl-fuzz as a traditional, \"dumb\" fuzzer.\n" + " For that, you can use the -n option - but expect much worse results.)\n", + doc_path); + + FATAL("No instrumentation detected"); + + } + + if (qemu_mode && + memmem(f_data, f_len, SHM_ENV_VAR, strlen(SHM_ENV_VAR) + 1)) { + + SAYF("\n" cLRD "[-] " cRST + "This program appears to be instrumented with afl-gcc, but is being run in\n" + " QEMU mode (-Q). This is probably not what you want - this setup will be\n" + " slow and offer no practical benefits.\n"); + + FATAL("Instrumentation found in -Q mode"); + + } + + if (memmem(f_data, f_len, "libasan.so", 10) || + memmem(f_data, f_len, "__msan_init", 11)) uses_asan = 1; + + /* Detect persistent & deferred init signatures in the binary. */ + + if (memmem(f_data, f_len, PERSIST_SIG, strlen(PERSIST_SIG) + 1)) { + + OKF(cPIN "Persistent mode binary detected."); + setenv(PERSIST_ENV_VAR, "1", 1); + persistent_mode = 1; + + } else if (getenv("AFL_PERSISTENT")) { + + WARNF("AFL_PERSISTENT is no longer supported and may misbehave!"); + + } + + if (memmem(f_data, f_len, DEFER_SIG, strlen(DEFER_SIG) + 1)) { + + OKF(cPIN "Deferred forkserver binary detected."); + setenv(DEFER_ENV_VAR, "1", 1); + deferred_mode = 1; + + } else if (getenv("AFL_DEFER_FORKSRV")) { + + WARNF("AFL_DEFER_FORKSRV is no longer supported and may misbehave!"); + + } + + if (munmap(f_data, f_len)) PFATAL("unmap() failed"); + +} + + +/* Trim and possibly create a banner for the run. */ + +static void fix_up_banner(u8* name) { + + if (!use_banner) { + + if (sync_id) { + + use_banner = sync_id; + + } else { + + u8* trim = strrchr(name, '/'); + if (!trim) use_banner = name; else use_banner = trim + 1; + + } + + } + + if (strlen(use_banner) > 40) { + + u8* tmp = ck_alloc(44); + sprintf(tmp, "%.40s...", use_banner); + use_banner = tmp; + + } + +} + + +/* Check if we're on TTY. */ + +static void check_if_tty(void) { + + struct winsize ws; + + if (getenv("AFL_NO_UI")) { + OKF("Disabling the UI because AFL_NO_UI is set."); + not_on_tty = 1; + return; + } + + if (ioctl(1, TIOCGWINSZ, &ws)) { + + if (errno == ENOTTY) { + OKF("Looks like we're not running on a tty, so I'll be a bit less verbose."); + not_on_tty = 1; + } + + return; + } + +} + + +/* Check terminal dimensions after resize. */ + +static void check_term_size(void) { + + struct winsize ws; + + term_too_small = 0; + + if (ioctl(1, TIOCGWINSZ, &ws)) return; + + if (ws.ws_row == 0 && ws.ws_col == 0) return; + if (ws.ws_row < 25 || ws.ws_col < 80) term_too_small = 1; + +} + + + +/* Display usage hints. */ + +static void usage(u8* argv0) { + + SAYF("\n%s [ options ] -- /path/to/fuzzed_app [ ... ]\n\n" + + "Required parameters:\n\n" + + " -i dir - input directory with test cases\n" + " -o dir - output directory for fuzzer findings\n\n" + + "Execution control settings:\n\n" + + " -f file - location read by the fuzzed program (stdin)\n" + " -t msec - timeout for each run (auto-scaled, 50-%u ms)\n" + " -m megs - memory limit for child process (%u MB)\n" + " -Q - use binary-only instrumentation (QEMU mode)\n\n" + + "Fuzzing behavior settings:\n\n" + + " -d - quick & dirty mode (skips deterministic steps)\n" + " -n - fuzz without instrumentation (dumb mode)\n" + " -x dir - optional fuzzer dictionary (see README)\n\n" + + "Other stuff:\n\n" + + " -T text - text banner to show on the screen\n" + " -M / -S id - distributed mode (see parallel_fuzzing.txt)\n" + " -C - crash exploration mode (the peruvian rabbit thing)\n" + " -V - show version number and exit\n\n" + " -b cpu_id - bind the fuzzing process to the specified CPU core\n\n" + + "For additional tips, please consult %s/README.\n\n", + + argv0, EXEC_TIMEOUT, MEM_LIMIT, doc_path); + + exit(1); + +} + + +/* Prepare output directories and fds. */ + +EXP_ST void setup_dirs_fds(void) { + + u8* tmp; + s32 fd; + + ACTF("Setting up output directories..."); + + if (sync_id && mkdir(sync_dir, 0700) && errno != EEXIST) + PFATAL("Unable to create '%s'", sync_dir); + + if (mkdir(out_dir, 0700)) { + + if (errno != EEXIST) PFATAL("Unable to create '%s'", out_dir); + + maybe_delete_out_dir(); + + } else { + + if (in_place_resume) + FATAL("Resume attempted but old output directory not found"); + + out_dir_fd = open(out_dir, O_RDONLY); + +#ifndef __sun + + if (out_dir_fd < 0 || flock(out_dir_fd, LOCK_EX | LOCK_NB)) + PFATAL("Unable to flock() output directory."); + +#endif /* !__sun */ + + } + + /* Queue directory for any starting & discovered paths. */ + + tmp = alloc_printf("%s/queue", out_dir); + if (mkdir(tmp, 0700)) PFATAL("Unable to create '%s'", tmp); + ck_free(tmp); + + /* Top-level directory for queue metadata used for session + resume and related tasks. */ + + tmp = alloc_printf("%s/queue/.state/", out_dir); + if (mkdir(tmp, 0700)) PFATAL("Unable to create '%s'", tmp); + ck_free(tmp); + + /* Directory for flagging queue entries that went through + deterministic fuzzing in the past. */ + + tmp = alloc_printf("%s/queue/.state/deterministic_done/", out_dir); + if (mkdir(tmp, 0700)) PFATAL("Unable to create '%s'", tmp); + ck_free(tmp); + + /* Directory with the auto-selected dictionary entries. */ + + tmp = alloc_printf("%s/queue/.state/auto_extras/", out_dir); + if (mkdir(tmp, 0700)) PFATAL("Unable to create '%s'", tmp); + ck_free(tmp); + + /* The set of paths currently deemed redundant. */ + + tmp = alloc_printf("%s/queue/.state/redundant_edges/", out_dir); + if (mkdir(tmp, 0700)) PFATAL("Unable to create '%s'", tmp); + ck_free(tmp); + + /* The set of paths showing variable behavior. */ + + tmp = alloc_printf("%s/queue/.state/variable_behavior/", out_dir); + if (mkdir(tmp, 0700)) PFATAL("Unable to create '%s'", tmp); + ck_free(tmp); + + /* Sync directory for keeping track of cooperating fuzzers. */ + + if (sync_id) { + + tmp = alloc_printf("%s/.synced/", out_dir); + + if (mkdir(tmp, 0700) && (!in_place_resume || errno != EEXIST)) + PFATAL("Unable to create '%s'", tmp); + + ck_free(tmp); + + } + + /* All recorded crashes. */ + + tmp = alloc_printf("%s/crashes", out_dir); + if (mkdir(tmp, 0700)) PFATAL("Unable to create '%s'", tmp); + ck_free(tmp); + + /* All recorded hangs. */ + + tmp = alloc_printf("%s/hangs", out_dir); + if (mkdir(tmp, 0700)) PFATAL("Unable to create '%s'", tmp); + ck_free(tmp); + + /* Generally useful file descriptors. */ + + dev_null_fd = open("/dev/null", O_RDWR); + if (dev_null_fd < 0) PFATAL("Unable to open /dev/null"); + + dev_urandom_fd = open("/dev/urandom", O_RDONLY); + if (dev_urandom_fd < 0) PFATAL("Unable to open /dev/urandom"); + + /* Gnuplot output file. */ + + tmp = alloc_printf("%s/plot_data", out_dir); + fd = open(tmp, O_WRONLY | O_CREAT | O_EXCL, 0600); + if (fd < 0) PFATAL("Unable to create '%s'", tmp); + ck_free(tmp); + + plot_file = fdopen(fd, "w"); + if (!plot_file) PFATAL("fdopen() failed"); + + fprintf(plot_file, "# unix_time, cycles_done, cur_path, paths_total, " + "pending_total, pending_favs, map_size, unique_crashes, " + "unique_hangs, max_depth, execs_per_sec\n"); + /* ignore errors */ + +} + + +/* Setup the output file for fuzzed data, if not using -f. */ + +EXP_ST void setup_stdio_file(void) { + + u8* fn = alloc_printf("%s/.cur_input", out_dir); + + unlink(fn); /* Ignore errors */ + + out_fd = open(fn, O_RDWR | O_CREAT | O_EXCL, 0600); + + if (out_fd < 0) PFATAL("Unable to create '%s'", fn); + + ck_free(fn); + +} + + +/* Make sure that core dumps don't go to a program. */ + +static void check_crash_handling(void) { + +#ifdef __APPLE__ + + /* Yuck! There appears to be no simple C API to query for the state of + loaded daemons on MacOS X, and I'm a bit hesitant to do something + more sophisticated, such as disabling crash reporting via Mach ports, + until I get a box to test the code. So, for now, we check for crash + reporting the awful way. */ + + if (system("launchctl list 2>/dev/null | grep -q '\\.ReportCrash$'")) return; + + SAYF("\n" cLRD "[-] " cRST + "Whoops, your system is configured to forward crash notifications to an\n" + " external crash reporting utility. This will cause issues due to the\n" + " extended delay between the fuzzed binary malfunctioning and this fact\n" + " being relayed to the fuzzer via the standard waitpid() API.\n\n" + " To avoid having crashes misinterpreted as timeouts, please run the\n" + " following commands:\n\n" + + " SL=/System/Library; PL=com.apple.ReportCrash\n" + " launchctl unload -w ${SL}/LaunchAgents/${PL}.plist\n" + " sudo launchctl unload -w ${SL}/LaunchDaemons/${PL}.Root.plist\n"); + + if (!getenv("AFL_I_DONT_CARE_ABOUT_MISSING_CRASHES")) + FATAL("Crash reporter detected"); + +#else + + /* This is Linux specific, but I don't think there's anything equivalent on + *BSD, so we can just let it slide for now. */ + + s32 fd = open("/proc/sys/kernel/core_pattern", O_RDONLY); + u8 fchar; + + if (fd < 0) return; + + ACTF("Checking core_pattern..."); + + if (read(fd, &fchar, 1) == 1 && fchar == '|') { + + SAYF("\n" cLRD "[-] " cRST + "Hmm, your system is configured to send core dump notifications to an\n" + " external utility. This will cause issues: there will be an extended delay\n" + " between stumbling upon a crash and having this information relayed to the\n" + " fuzzer via the standard waitpid() API.\n\n" + + " To avoid having crashes misinterpreted as timeouts, please log in as root\n" + " and temporarily modify /proc/sys/kernel/core_pattern, like so:\n\n" + + " echo core >/proc/sys/kernel/core_pattern\n"); + + if (!getenv("AFL_I_DONT_CARE_ABOUT_MISSING_CRASHES")) + FATAL("Pipe at the beginning of 'core_pattern'"); + + } + + close(fd); + +#endif /* ^__APPLE__ */ + +} + + +/* Check CPU governor. */ + +static void check_cpu_governor(void) { + + FILE* f; + u8 tmp[128]; + u64 min = 0, max = 0; + + if (getenv("AFL_SKIP_CPUFREQ")) return; + + f = fopen("/sys/devices/system/cpu/cpu0/cpufreq/scaling_governor", "r"); + if (!f) return; + + ACTF("Checking CPU scaling governor..."); + + if (!fgets(tmp, 128, f)) PFATAL("fgets() failed"); + + fclose(f); + + if (!strncmp(tmp, "perf", 4)) return; + + f = fopen("/sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq", "r"); + + if (f) { + if (fscanf(f, "%llu", &min) != 1) min = 0; + fclose(f); + } + + f = fopen("/sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq", "r"); + + if (f) { + if (fscanf(f, "%llu", &max) != 1) max = 0; + fclose(f); + } + + if (min == max) return; + + SAYF("\n" cLRD "[-] " cRST + "Whoops, your system uses on-demand CPU frequency scaling, adjusted\n" + " between %llu and %llu MHz. Unfortunately, the scaling algorithm in the\n" + " kernel is imperfect and can miss the short-lived processes spawned by\n" + " afl-fuzz. To keep things moving, run these commands as root:\n\n" + + " cd /sys/devices/system/cpu\n" + " echo performance | tee cpu*/cpufreq/scaling_governor\n\n" + + " You can later go back to the original state by replacing 'performance' with\n" + " 'ondemand'. If you don't want to change the settings, set AFL_SKIP_CPUFREQ\n" + " to make afl-fuzz skip this check - but expect some performance drop.\n", + min / 1024, max / 1024); + + FATAL("Suboptimal CPU scaling governor"); + +} + + +/* Count the number of logical CPU cores. */ + +static void get_core_count(void) { + + u32 cur_runnable = 0; + +#if defined(__APPLE__) || defined(__FreeBSD__) || defined (__OpenBSD__) + + size_t s = sizeof(cpu_core_count); + + /* On *BSD systems, we can just use a sysctl to get the number of CPUs. */ + +#ifdef __APPLE__ + + if (sysctlbyname("hw.logicalcpu", &cpu_core_count, &s, NULL, 0) < 0) + return; + +#else + + int s_name[2] = { CTL_HW, HW_NCPU }; + + if (sysctl(s_name, 2, &cpu_core_count, &s, NULL, 0) < 0) return; + +#endif /* ^__APPLE__ */ + +#else + +#ifdef HAVE_AFFINITY + + cpu_core_count = sysconf(_SC_NPROCESSORS_ONLN); + +#else + + FILE* f = fopen("/proc/stat", "r"); + u8 tmp[1024]; + + if (!f) return; + + while (fgets(tmp, sizeof(tmp), f)) + if (!strncmp(tmp, "cpu", 3) && isdigit(tmp[3])) cpu_core_count++; + + fclose(f); + +#endif /* ^HAVE_AFFINITY */ + +#endif /* ^(__APPLE__ || __FreeBSD__ || __OpenBSD__) */ + + if (cpu_core_count > 0) { + + cur_runnable = (u32)get_runnable_processes(); + +#if defined(__APPLE__) || defined(__FreeBSD__) || defined (__OpenBSD__) + + /* Add ourselves, since the 1-minute average doesn't include that yet. */ + + cur_runnable++; + +#endif /* __APPLE__ || __FreeBSD__ || __OpenBSD__ */ + + OKF("You have %u CPU core%s and %u runnable tasks (utilization: %0.0f%%).", + cpu_core_count, cpu_core_count > 1 ? "s" : "", + cur_runnable, cur_runnable * 100.0 / cpu_core_count); + + if (cpu_core_count > 1) { + + if (cur_runnable > cpu_core_count * 1.5) { + + WARNF("System under apparent load, performance may be spotty."); + + } else if (cur_runnable + 1 <= cpu_core_count) { + + OKF("Try parallel jobs - see %s/parallel_fuzzing.txt.", doc_path); + + } + + } + + } else { + + cpu_core_count = 0; + WARNF("Unable to figure out the number of CPU cores."); + + } + +} + + +/* Validate and fix up out_dir and sync_dir when using -S. */ + +static void fix_up_sync(void) { + + u8* x = sync_id; + + if (dumb_mode) + FATAL("-S / -M and -n are mutually exclusive"); + + if (skip_deterministic) { + + if (force_deterministic) + FATAL("use -S instead of -M -d"); + else + FATAL("-S already implies -d"); + + } + + while (*x) { + + if (!isalnum(*x) && *x != '_' && *x != '-') + FATAL("Non-alphanumeric fuzzer ID specified via -S or -M"); + + x++; + + } + + if (strlen(sync_id) > 32) FATAL("Fuzzer ID too long"); + + x = alloc_printf("%s/%s", out_dir, sync_id); + + sync_dir = out_dir; + out_dir = x; + + if (!force_deterministic) { + skip_deterministic = 1; + use_splicing = 1; + } + +} + + +/* Handle screen resize (SIGWINCH). */ + +static void handle_resize(int sig) { + clear_screen = 1; +} + + +/* Check ASAN options. */ + +static void check_asan_opts(void) { + u8* x = getenv("ASAN_OPTIONS"); + + if (x) { + + if (!strstr(x, "abort_on_error=1")) + FATAL("Custom ASAN_OPTIONS set without abort_on_error=1 - please fix!"); + + if (!strstr(x, "symbolize=0")) + FATAL("Custom ASAN_OPTIONS set without symbolize=0 - please fix!"); + + } + + x = getenv("MSAN_OPTIONS"); + + if (x) { + + if (!strstr(x, "exit_code=" STRINGIFY(MSAN_ERROR))) + FATAL("Custom MSAN_OPTIONS set without exit_code=" + STRINGIFY(MSAN_ERROR) " - please fix!"); + + if (!strstr(x, "symbolize=0")) + FATAL("Custom MSAN_OPTIONS set without symbolize=0 - please fix!"); + + } + +} + + +/* Detect @@ in args. */ + +EXP_ST void detect_file_args(char** argv) { + + u32 i = 0; + u8* cwd = getcwd(NULL, 0); + + if (!cwd) PFATAL("getcwd() failed"); + + while (argv[i]) { + + u8* aa_loc = strstr(argv[i], "@@"); + + if (aa_loc) { + + u8 *aa_subst, *n_arg; + + /* If we don't have a file name chosen yet, use a safe default. */ + + if (!out_file) + out_file = alloc_printf("%s/.cur_input", out_dir); + + /* Be sure that we're always using fully-qualified paths. */ + + if (out_file[0] == '/') aa_subst = out_file; + else aa_subst = alloc_printf("%s/%s", cwd, out_file); + + /* Construct a replacement argv value. */ + + *aa_loc = 0; + n_arg = alloc_printf("%s%s%s", argv[i], aa_subst, aa_loc + 2); + argv[i] = n_arg; + *aa_loc = '@'; + + if (out_file[0] != '/') ck_free(aa_subst); + + } + + i++; + + } + + free(cwd); /* not tracked */ + +} + + +/* Set up signal handlers. More complicated that needs to be, because libc on + Solaris doesn't resume interrupted reads(), sets SA_RESETHAND when you call + siginterrupt(), and does other unnecessary things. */ + +EXP_ST void setup_signal_handlers(void) { + + struct sigaction sa; + + sa.sa_handler = NULL; + sa.sa_flags = SA_RESTART; + sa.sa_sigaction = NULL; + + sigemptyset(&sa.sa_mask); + + /* Various ways of saying "stop". */ + + sa.sa_handler = handle_stop_sig; + sigaction(SIGHUP, &sa, NULL); + sigaction(SIGINT, &sa, NULL); + sigaction(SIGTERM, &sa, NULL); + + /* Exec timeout notifications. */ + + sa.sa_handler = handle_timeout; + sigaction(SIGALRM, &sa, NULL); + + /* Window resize */ + + sa.sa_handler = handle_resize; + sigaction(SIGWINCH, &sa, NULL); + + /* SIGUSR1: skip entry */ + + sa.sa_handler = handle_skipreq; + sigaction(SIGUSR1, &sa, NULL); + + /* Things we don't care about. */ + + sa.sa_handler = SIG_IGN; + sigaction(SIGTSTP, &sa, NULL); + sigaction(SIGPIPE, &sa, NULL); + +} + + +/* Rewrite argv for QEMU. */ + +static char** get_qemu_argv(u8* own_loc, char** argv, int argc) { + + char** new_argv = ck_alloc(sizeof(char*) * (argc + 4)); + u8 *tmp, *cp, *rsl, *own_copy; + + /* Workaround for a QEMU stability glitch. */ + + setenv("QEMU_LOG", "nochain", 1); + + memcpy(new_argv + 3, argv + 1, sizeof(char*) * argc); + + new_argv[2] = target_path; + new_argv[1] = "--"; + + /* Now we need to actually find the QEMU binary to put in argv[0]. */ + + tmp = getenv("AFL_PATH"); + + if (tmp) { + + cp = alloc_printf("%s/afl-qemu-trace", tmp); + + if (access(cp, X_OK)) + FATAL("Unable to find '%s'", tmp); + + target_path = new_argv[0] = cp; + return new_argv; + + } + + own_copy = ck_strdup(own_loc); + rsl = strrchr(own_copy, '/'); + + if (rsl) { + + *rsl = 0; + + cp = alloc_printf("%s/afl-qemu-trace", own_copy); + ck_free(own_copy); + + if (!access(cp, X_OK)) { + + target_path = new_argv[0] = cp; + return new_argv; + + } + + } else ck_free(own_copy); + + if (!access(BIN_PATH "/afl-qemu-trace", X_OK)) { + + target_path = new_argv[0] = ck_strdup(BIN_PATH "/afl-qemu-trace"); + return new_argv; + + } + + SAYF("\n" cLRD "[-] " cRST + "Oops, unable to find the 'afl-qemu-trace' binary. The binary must be built\n" + " separately by following the instructions in qemu_mode/README.qemu. If you\n" + " already have the binary installed, you may need to specify AFL_PATH in the\n" + " environment.\n\n" + + " Of course, even without QEMU, afl-fuzz can still work with binaries that are\n" + " instrumented at compile time with afl-gcc. It is also possible to use it as a\n" + " traditional \"dumb\" fuzzer by specifying '-n' in the command line.\n"); + + FATAL("Failed to locate 'afl-qemu-trace'."); + +} + + +/* Make a copy of the current command line. */ + +static void save_cmdline(u32 argc, char** argv) { + + u32 len = 1, i; + u8* buf; + + for (i = 0; i < argc; i++) + len += strlen(argv[i]) + 1; + + buf = orig_cmdline = ck_alloc(len); + + for (i = 0; i < argc; i++) { + + u32 l = strlen(argv[i]); + + memcpy(buf, argv[i], l); + buf += l; + + if (i != argc - 1) *(buf++) = ' '; + + } + + *buf = 0; + +} + + +#ifndef AFL_LIB + +/* Main entry point */ + +int main(int argc, char** argv) { + + s32 opt; + u64 prev_queued = 0; + u32 sync_interval_cnt = 0, seek_to; + u8 *extras_dir = 0; + u8 mem_limit_given = 0; + u8 exit_1 = !!getenv("AFL_BENCH_JUST_ONE"); + char** use_argv; + + struct timeval tv; + struct timezone tz; + + SAYF(cCYA "afl-fuzz " cBRI VERSION cRST " by \n"); + + doc_path = access(DOC_PATH, F_OK) ? "docs" : DOC_PATH; + + gettimeofday(&tv, &tz); + srandom(tv.tv_sec ^ tv.tv_usec ^ getpid()); + + while ((opt = getopt(argc, argv, "+i:o:f:m:b:t:T:dnCB:S:M:x:QV")) > 0) + + switch (opt) { + + case 'i': /* input dir */ + + if (in_dir) FATAL("Multiple -i options not supported"); + in_dir = optarg; + + if (!strcmp(in_dir, "-")) in_place_resume = 1; + + break; + + case 'o': /* output dir */ + + if (out_dir) FATAL("Multiple -o options not supported"); + out_dir = optarg; + break; + + case 'M': { /* master sync ID */ + + u8* c; + + if (sync_id) FATAL("Multiple -S or -M options not supported"); + sync_id = ck_strdup(optarg); + + if ((c = strchr(sync_id, ':'))) { + + *c = 0; + + if (sscanf(c + 1, "%u/%u", &master_id, &master_max) != 2 || + !master_id || !master_max || master_id > master_max || + master_max > 1000000) FATAL("Bogus master ID passed to -M"); + + } + + force_deterministic = 1; + + } + + break; + + case 'S': + + if (sync_id) FATAL("Multiple -S or -M options not supported"); + sync_id = ck_strdup(optarg); + break; + + case 'f': /* target file */ + + if (out_file) FATAL("Multiple -f options not supported"); + out_file = optarg; + break; + + case 'x': /* dictionary */ + + if (extras_dir) FATAL("Multiple -x options not supported"); + extras_dir = optarg; + break; + + case 't': { /* timeout */ + + u8 suffix = 0; + + if (timeout_given) FATAL("Multiple -t options not supported"); + + if (sscanf(optarg, "%u%c", &exec_tmout, &suffix) < 1 || + optarg[0] == '-') FATAL("Bad syntax used for -t"); + + if (exec_tmout < 5) FATAL("Dangerously low value of -t"); + + if (suffix == '+') timeout_given = 2; else timeout_given = 1; + + break; + + } + + case 'm': { /* mem limit */ + + u8 suffix = 'M'; + + if (mem_limit_given) FATAL("Multiple -m options not supported"); + mem_limit_given = 1; + + if (!strcmp(optarg, "none")) { + + mem_limit = 0; + break; + + } + + if (sscanf(optarg, "%llu%c", &mem_limit, &suffix) < 1 || + optarg[0] == '-') FATAL("Bad syntax used for -m"); + + switch (suffix) { + + case 'T': mem_limit *= 1024 * 1024; break; + case 'G': mem_limit *= 1024; break; + case 'k': mem_limit /= 1024; break; + case 'M': break; + + default: FATAL("Unsupported suffix or bad syntax for -m"); + + } + + if (mem_limit < 5) FATAL("Dangerously low value of -m"); + + if (sizeof(rlim_t) == 4 && mem_limit > 2000) + FATAL("Value of -m out of range on 32-bit systems"); + + } + + break; + + case 'b': { /* bind CPU core */ + + if (cpu_to_bind_given) FATAL("Multiple -b options not supported"); + cpu_to_bind_given = 1; + + if (sscanf(optarg, "%u", &cpu_to_bind) < 1 || + optarg[0] == '-') FATAL("Bad syntax used for -b"); + + break; + + } + + case 'd': /* skip deterministic */ + + if (skip_deterministic) FATAL("Multiple -d options not supported"); + skip_deterministic = 1; + use_splicing = 1; + break; + + case 'B': /* load bitmap */ + + /* This is a secret undocumented option! It is useful if you find + an interesting test case during a normal fuzzing process, and want + to mutate it without rediscovering any of the test cases already + found during an earlier run. + + To use this mode, you need to point -B to the fuzz_bitmap produced + by an earlier run for the exact same binary... and that's it. + + I only used this once or twice to get variants of a particular + file, so I'm not making this an official setting. */ + + if (in_bitmap) FATAL("Multiple -B options not supported"); + + in_bitmap = optarg; + read_bitmap(in_bitmap); + break; + + case 'C': /* crash mode */ + + if (crash_mode) FATAL("Multiple -C options not supported"); + crash_mode = FAULT_CRASH; + break; + + case 'n': /* dumb mode */ + + if (dumb_mode) FATAL("Multiple -n options not supported"); + if (getenv("AFL_DUMB_FORKSRV")) dumb_mode = 2; else dumb_mode = 1; + + break; + + case 'T': /* banner */ + + if (use_banner) FATAL("Multiple -T options not supported"); + use_banner = optarg; + break; + + case 'Q': /* QEMU mode */ + + if (qemu_mode) FATAL("Multiple -Q options not supported"); + qemu_mode = 1; + + if (!mem_limit_given) mem_limit = MEM_LIMIT_QEMU; + + break; + + case 'V': /* Show version number */ + + /* Version number has been printed already, just quit. */ + exit(0); + + default: + + usage(argv[0]); + + } + + if (optind == argc || !in_dir || !out_dir) usage(argv[0]); + + setup_signal_handlers(); + check_asan_opts(); + + if (sync_id) fix_up_sync(); + + if (!strcmp(in_dir, out_dir)) + FATAL("Input and output directories can't be the same"); + + if (dumb_mode) { + + if (crash_mode) FATAL("-C and -n are mutually exclusive"); + if (qemu_mode) FATAL("-Q and -n are mutually exclusive"); + + } + + if (getenv("AFL_NO_FORKSRV")) no_forkserver = 1; + if (getenv("AFL_NO_CPU_RED")) no_cpu_meter_red = 1; + if (getenv("AFL_NO_ARITH")) no_arith = 1; + if (getenv("AFL_SHUFFLE_QUEUE")) shuffle_queue = 1; + if (getenv("AFL_FAST_CAL")) fast_cal = 1; + + if (getenv("AFL_HANG_TMOUT")) { + hang_tmout = atoi(getenv("AFL_HANG_TMOUT")); + if (!hang_tmout) FATAL("Invalid value of AFL_HANG_TMOUT"); + } + + if (dumb_mode == 2 && no_forkserver) + FATAL("AFL_DUMB_FORKSRV and AFL_NO_FORKSRV are mutually exclusive"); + + if (getenv("AFL_PRELOAD")) { + setenv("LD_PRELOAD", getenv("AFL_PRELOAD"), 1); + setenv("DYLD_INSERT_LIBRARIES", getenv("AFL_PRELOAD"), 1); + } + + if (getenv("AFL_LD_PRELOAD")) + FATAL("Use AFL_PRELOAD instead of AFL_LD_PRELOAD"); + + save_cmdline(argc, argv); + + fix_up_banner(argv[optind]); + + check_if_tty(); + + get_core_count(); + +#ifdef HAVE_AFFINITY + bind_to_free_cpu(); +#endif /* HAVE_AFFINITY */ + + check_crash_handling(); + check_cpu_governor(); + + setup_post(); + setup_shm(); + init_count_class16(); + + setup_dirs_fds(); + read_testcases(); + load_auto(); + + pivot_inputs(); + + if (extras_dir) load_extras(extras_dir); + + if (!timeout_given) find_timeout(); + + detect_file_args(argv + optind + 1); + + if (!out_file) setup_stdio_file(); + + check_binary(argv[optind]); + + start_time = get_cur_time(); + + if (qemu_mode) + use_argv = get_qemu_argv(argv[0], argv + optind, argc - optind); + else + use_argv = argv + optind; + + perform_dry_run(use_argv); + + cull_queue(); + + show_init_stats(); + + seek_to = find_start_position(); + + write_stats_file(0, 0, 0); + save_auto(); + + if (stop_soon) goto stop_fuzzing; + + /* Woop woop woop */ + + if (!not_on_tty) { + sleep(4); + start_time += 4000; + if (stop_soon) goto stop_fuzzing; + } + + while (1) { + + u8 skipped_fuzz; + + cull_queue(); + + if (!queue_cur) { + + queue_cycle++; + current_entry = 0; + cur_skipped_paths = 0; + queue_cur = queue; + + while (seek_to) { + current_entry++; + seek_to--; + queue_cur = queue_cur->next; + } + + show_stats(); + + if (not_on_tty) { + ACTF("Entering queue cycle %llu.", queue_cycle); + fflush(stdout); + } + + /* If we had a full queue cycle with no new finds, try + recombination strategies next. */ + + if (queued_paths == prev_queued) { + + if (use_splicing) cycles_wo_finds++; else use_splicing = 1; + + } else cycles_wo_finds = 0; + + prev_queued = queued_paths; + + if (sync_id && queue_cycle == 1 && getenv("AFL_IMPORT_FIRST")) + sync_fuzzers(use_argv); + + } + + skipped_fuzz = fuzz_one(use_argv); + + if (!stop_soon && sync_id && !skipped_fuzz) { + + if (!(sync_interval_cnt++ % SYNC_INTERVAL)) + sync_fuzzers(use_argv); + + } + + if (!stop_soon && exit_1) stop_soon = 2; + + if (stop_soon) break; + + queue_cur = queue_cur->next; + current_entry++; + + } + + if (queue_cur) show_stats(); + + /* If we stopped programmatically, we kill the forkserver and the current runner. + If we stopped manually, this is done by the signal handler. */ + if (stop_soon == 2) { + if (child_pid > 0) kill(child_pid, SIGKILL); + if (forksrv_pid > 0) kill(forksrv_pid, SIGKILL); + } + /* Now that we've killed the forkserver, we wait for it to be able to get rusage stats. */ + if (waitpid(forksrv_pid, NULL, 0) <= 0) { + WARNF("error waitpid\n"); + } + + write_bitmap(); + write_stats_file(0, 0, 0); + save_auto(); + +stop_fuzzing: + + SAYF(CURSOR_SHOW cLRD "\n\n+++ Testing aborted %s +++\n" cRST, + stop_soon == 2 ? "programmatically" : "by user"); + + /* Running for more than 30 minutes but still doing first cycle? */ + + if (queue_cycle == 1 && get_cur_time() - start_time > 30 * 60 * 1000) { + + SAYF("\n" cYEL "[!] " cRST + "Stopped during the first cycle, results may be incomplete.\n" + " (For info on resuming, see %s/README.)\n", doc_path); + + } + + fclose(plot_file); + destroy_queue(); + destroy_extras(); + ck_free(target_path); + ck_free(sync_id); + + alloc_report(); + + OKF("We're done here. Have a nice day!\n"); + + exit(0); + +} + +#endif /* !AFL_LIB */ diff --git a/src/afl-gcc.c b/src/afl-gcc.c new file mode 100644 index 0000000..f0e4d85 --- /dev/null +++ b/src/afl-gcc.c @@ -0,0 +1,346 @@ +/* + Copyright 2013 Google LLC All rights reserved. + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at: + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +*/ + +/* + american fuzzy lop - wrapper for GCC and clang + ---------------------------------------------- + + Written and maintained by Michal Zalewski + + This program is a drop-in replacement for GCC or clang. The most common way + of using it is to pass the path to afl-gcc or afl-clang via CC when invoking + ./configure. + + (Of course, use CXX and point it to afl-g++ / afl-clang++ for C++ code.) + + The wrapper needs to know the path to afl-as (renamed to 'as'). The default + is /usr/local/lib/afl/. A convenient way to specify alternative directories + would be to set AFL_PATH. + + If AFL_HARDEN is set, the wrapper will compile the target app with various + hardening options that may help detect memory management issues more + reliably. You can also specify AFL_USE_ASAN to enable ASAN. + + If you want to call a non-default compiler as a next step of the chain, + specify its location via AFL_CC or AFL_CXX. + +*/ + +#define AFL_MAIN + +#include "config.h" +#include "types.h" +#include "debug.h" +#include "alloc-inl.h" + +#include +#include +#include +#include + +static u8* as_path; /* Path to the AFL 'as' wrapper */ +static u8** cc_params; /* Parameters passed to the real CC */ +static u32 cc_par_cnt = 1; /* Param count, including argv0 */ +static u8 be_quiet, /* Quiet mode */ + clang_mode; /* Invoked as afl-clang*? */ + + +/* Try to find our "fake" GNU assembler in AFL_PATH or at the location derived + from argv[0]. If that fails, abort. */ + +static void find_as(u8* argv0) { + + u8 *afl_path = getenv("AFL_PATH"); + u8 *slash, *tmp; + + if (afl_path) { + + tmp = alloc_printf("%s/as", afl_path); + + if (!access(tmp, X_OK)) { + as_path = afl_path; + ck_free(tmp); + return; + } + + ck_free(tmp); + + } + + slash = strrchr(argv0, '/'); + + if (slash) { + + u8 *dir; + + *slash = 0; + dir = ck_strdup(argv0); + *slash = '/'; + + tmp = alloc_printf("%s/afl-as", dir); + + if (!access(tmp, X_OK)) { + as_path = dir; + ck_free(tmp); + return; + } + + ck_free(tmp); + ck_free(dir); + + } + + if (!access(AFL_PATH "/as", X_OK)) { + as_path = AFL_PATH; + return; + } + + FATAL("Unable to find AFL wrapper binary for 'as'. Please set AFL_PATH"); + +} + + +/* Copy argv to cc_params, making the necessary edits. */ + +static void edit_params(u32 argc, char** argv) { + + u8 fortify_set = 0, asan_set = 0; + u8 *name; + +#if defined(__FreeBSD__) && defined(__x86_64__) + u8 m32_set = 0; +#endif + + cc_params = ck_alloc((argc + 128) * sizeof(u8*)); + + name = strrchr(argv[0], '/'); + if (!name) name = argv[0]; else name++; + + if (!strncmp(name, "afl-clang", 9)) { + + clang_mode = 1; + + setenv(CLANG_ENV_VAR, "1", 1); + + if (!strcmp(name, "afl-clang++")) { + u8* alt_cxx = getenv("AFL_CXX"); + cc_params[0] = alt_cxx ? alt_cxx : (u8*)"clang++"; + } else { + u8* alt_cc = getenv("AFL_CC"); + cc_params[0] = alt_cc ? alt_cc : (u8*)"clang"; + } + + } else { + + /* With GCJ and Eclipse installed, you can actually compile Java! The + instrumentation will work (amazingly). Alas, unhandled exceptions do + not call abort(), so afl-fuzz would need to be modified to equate + non-zero exit codes with crash conditions when working with Java + binaries. Meh. */ + +#ifdef __APPLE__ + + if (!strcmp(name, "afl-g++")) cc_params[0] = getenv("AFL_CXX"); + else if (!strcmp(name, "afl-gcj")) cc_params[0] = getenv("AFL_GCJ"); + else cc_params[0] = getenv("AFL_CC"); + + if (!cc_params[0]) { + + SAYF("\n" cLRD "[-] " cRST + "On Apple systems, 'gcc' is usually just a wrapper for clang. Please use the\n" + " 'afl-clang' utility instead of 'afl-gcc'. If you really have GCC installed,\n" + " set AFL_CC or AFL_CXX to specify the correct path to that compiler.\n"); + + FATAL("AFL_CC or AFL_CXX required on MacOS X"); + + } + +#else + + if (!strcmp(name, "afl-g++")) { + u8* alt_cxx = getenv("AFL_CXX"); + cc_params[0] = alt_cxx ? alt_cxx : (u8*)"g++"; + } else if (!strcmp(name, "afl-gcj")) { + u8* alt_cc = getenv("AFL_GCJ"); + cc_params[0] = alt_cc ? alt_cc : (u8*)"gcj"; + } else { + u8* alt_cc = getenv("AFL_CC"); + cc_params[0] = alt_cc ? alt_cc : (u8*)"gcc"; + } + +#endif /* __APPLE__ */ + + } + + while (--argc) { + u8* cur = *(++argv); + + if (!strncmp(cur, "-B", 2)) { + + if (!be_quiet) WARNF("-B is already set, overriding"); + + if (!cur[2] && argc > 1) { argc--; argv++; } + continue; + + } + + if (!strcmp(cur, "-integrated-as")) continue; + + if (!strcmp(cur, "-pipe")) continue; + +#if defined(__FreeBSD__) && defined(__x86_64__) + if (!strcmp(cur, "-m32")) m32_set = 1; +#endif + + if (!strcmp(cur, "-fsanitize=address") || + !strcmp(cur, "-fsanitize=memory")) asan_set = 1; + + if (strstr(cur, "FORTIFY_SOURCE")) fortify_set = 1; + + cc_params[cc_par_cnt++] = cur; + + } + + cc_params[cc_par_cnt++] = "-B"; + cc_params[cc_par_cnt++] = as_path; + + if (clang_mode) + cc_params[cc_par_cnt++] = "-no-integrated-as"; + + if (getenv("AFL_HARDEN")) { + + cc_params[cc_par_cnt++] = "-fstack-protector-all"; + + if (!fortify_set) + cc_params[cc_par_cnt++] = "-D_FORTIFY_SOURCE=2"; + + } + + if (asan_set) { + + /* Pass this on to afl-as to adjust map density. */ + + setenv("AFL_USE_ASAN", "1", 1); + + } else if (getenv("AFL_USE_ASAN")) { + + if (getenv("AFL_USE_MSAN")) + FATAL("ASAN and MSAN are mutually exclusive"); + + if (getenv("AFL_HARDEN")) + FATAL("ASAN and AFL_HARDEN are mutually exclusive"); + + cc_params[cc_par_cnt++] = "-U_FORTIFY_SOURCE"; + cc_params[cc_par_cnt++] = "-fsanitize=address"; + + } else if (getenv("AFL_USE_MSAN")) { + + if (getenv("AFL_USE_ASAN")) + FATAL("ASAN and MSAN are mutually exclusive"); + + if (getenv("AFL_HARDEN")) + FATAL("MSAN and AFL_HARDEN are mutually exclusive"); + + cc_params[cc_par_cnt++] = "-U_FORTIFY_SOURCE"; + cc_params[cc_par_cnt++] = "-fsanitize=memory"; + + + } + + if (!getenv("AFL_DONT_OPTIMIZE")) { + +#if defined(__FreeBSD__) && defined(__x86_64__) + + /* On 64-bit FreeBSD systems, clang -g -m32 is broken, but -m32 itself + works OK. This has nothing to do with us, but let's avoid triggering + that bug. */ + + if (!clang_mode || !m32_set) + cc_params[cc_par_cnt++] = "-g"; + +#else + + cc_params[cc_par_cnt++] = "-g"; + +#endif + + cc_params[cc_par_cnt++] = "-O3"; + cc_params[cc_par_cnt++] = "-funroll-loops"; + + /* Two indicators that you're building for fuzzing; one of them is + AFL-specific, the other is shared with libfuzzer. */ + + cc_params[cc_par_cnt++] = "-D__AFL_COMPILER=1"; + cc_params[cc_par_cnt++] = "-DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION=1"; + + } + + if (getenv("AFL_NO_BUILTIN")) { + + cc_params[cc_par_cnt++] = "-fno-builtin-strcmp"; + cc_params[cc_par_cnt++] = "-fno-builtin-strncmp"; + cc_params[cc_par_cnt++] = "-fno-builtin-strcasecmp"; + cc_params[cc_par_cnt++] = "-fno-builtin-strncasecmp"; + cc_params[cc_par_cnt++] = "-fno-builtin-memcmp"; + cc_params[cc_par_cnt++] = "-fno-builtin-strstr"; + cc_params[cc_par_cnt++] = "-fno-builtin-strcasestr"; + + } + + cc_params[cc_par_cnt] = NULL; + +} + + +/* Main entry point */ + +int main(int argc, char** argv) { + + if (isatty(2) && !getenv("AFL_QUIET")) { + + SAYF(cCYA "afl-cc " cBRI VERSION cRST " by \n"); + + } else be_quiet = 1; + + if (argc < 2) { + + SAYF("\n" + "This is a helper application for afl-fuzz. It serves as a drop-in replacement\n" + "for gcc or clang, letting you recompile third-party code with the required\n" + "runtime instrumentation. A common use pattern would be one of the following:\n\n" + + " CC=%s/afl-gcc ./configure\n" + " CXX=%s/afl-g++ ./configure\n\n" + + "You can specify custom next-stage toolchain via AFL_CC, AFL_CXX, and AFL_AS.\n" + "Setting AFL_HARDEN enables hardening optimizations in the compiled code.\n\n", + BIN_PATH, BIN_PATH); + + exit(1); + + } + + find_as(argv[0]); + + edit_params(argc, argv); + + execvp(cc_params[0], (char**)cc_params); + + FATAL("Oops, failed to execute '%s' - check your PATH", cc_params[0]); + + return 0; + +} diff --git a/src/afl-gotcpu.c b/src/afl-gotcpu.c new file mode 100644 index 0000000..630b7ff --- /dev/null +++ b/src/afl-gotcpu.c @@ -0,0 +1,260 @@ +/* + Copyright 2015 Google LLC All rights reserved. + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at: + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +*/ + +/* + american fuzzy lop - free CPU gizmo + ----------------------------------- + + Written and maintained by Michal Zalewski + + This tool provides a fairly accurate measurement of CPU preemption rate. + It is meant to complement the quick-and-dirty load average widget shown + in the afl-fuzz UI. See docs/parallel_fuzzing.txt for more info. + + For some work loads, the tool may actually suggest running more instances + than you have CPU cores. This can happen if the tested program is spending + a portion of its run time waiting for I/O, rather than being 100% + CPU-bound. + + The idea for the getrusage()-based approach comes from Jakub Wilk. +*/ + +#define AFL_MAIN +#include "android-ashmem.h" +#define _GNU_SOURCE + +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +#include "types.h" +#include "debug.h" + +#ifdef __linux__ +# define HAVE_AFFINITY 1 +#endif /* __linux__ */ + + +/* Get unix time in microseconds. */ + +static u64 get_cur_time_us(void) { + + struct timeval tv; + struct timezone tz; + + gettimeofday(&tv, &tz); + + return (tv.tv_sec * 1000000ULL) + tv.tv_usec; + +} + + +/* Get CPU usage in microseconds. */ + +static u64 get_cpu_usage_us(void) { + + struct rusage u; + + getrusage(RUSAGE_SELF, &u); + + return (u.ru_utime.tv_sec * 1000000ULL) + u.ru_utime.tv_usec + + (u.ru_stime.tv_sec * 1000000ULL) + u.ru_stime.tv_usec; + +} + + +/* Measure preemption rate. */ + +static u32 measure_preemption(u32 target_ms) { + + static volatile u32 v1, v2; + + u64 st_t, en_t, st_c, en_c, real_delta, slice_delta; + s32 loop_repeats = 0; + + st_t = get_cur_time_us(); + st_c = get_cpu_usage_us(); + +repeat_loop: + + v1 = CTEST_BUSY_CYCLES; + + while (v1--) v2++; + sched_yield(); + + en_t = get_cur_time_us(); + + if (en_t - st_t < target_ms * 1000) { + loop_repeats++; + goto repeat_loop; + } + + /* Let's see what percentage of this time we actually had a chance to + run, and how much time was spent in the penalty box. */ + + en_c = get_cpu_usage_us(); + + real_delta = (en_t - st_t) / 1000; + slice_delta = (en_c - st_c) / 1000; + + return real_delta * 100 / slice_delta; + +} + + +/* Do the benchmark thing. */ + +int main(int argc, char** argv) { + +#ifdef HAVE_AFFINITY + + u32 cpu_cnt = sysconf(_SC_NPROCESSORS_ONLN), + idle_cpus = 0, maybe_cpus = 0, i; + + SAYF(cCYA "afl-gotcpu " cBRI VERSION cRST " by \n"); + + ACTF("Measuring per-core preemption rate (this will take %0.02f sec)...", + ((double)CTEST_CORE_TRG_MS) / 1000); + + for (i = 0; i < cpu_cnt; i++) { + + s32 fr = fork(); + + if (fr < 0) PFATAL("fork failed"); + + if (!fr) { + + cpu_set_t c; + u32 util_perc; + + CPU_ZERO(&c); + CPU_SET(i, &c); + + if (sched_setaffinity(0, sizeof(c), &c)) + PFATAL("sched_setaffinity failed for cpu %d", i); + + util_perc = measure_preemption(CTEST_CORE_TRG_MS); + + if (util_perc < 110) { + + SAYF(" Core #%u: " cLGN "AVAILABLE " cRST "(%u%%)\n", i, util_perc); + exit(0); + + } else if (util_perc < 250) { + + SAYF(" Core #%u: " cYEL "CAUTION " cRST "(%u%%)\n", i, util_perc); + exit(1); + + } + + SAYF(" Core #%u: " cLRD "OVERBOOKED " cRST "(%u%%)\n" cRST, i, + util_perc); + exit(2); + + } + + } + + for (i = 0; i < cpu_cnt; i++) { + + int ret; + if (waitpid(-1, &ret, 0) < 0) PFATAL("waitpid failed"); + + if (WEXITSTATUS(ret) == 0) idle_cpus++; + if (WEXITSTATUS(ret) <= 1) maybe_cpus++; + + } + + SAYF(cGRA "\n>>> "); + + if (idle_cpus) { + + if (maybe_cpus == idle_cpus) { + + SAYF(cLGN "PASS: " cRST "You can run more processes on %u core%s.", + idle_cpus, idle_cpus > 1 ? "s" : ""); + + } else { + + SAYF(cLGN "PASS: " cRST "You can run more processes on %u to %u core%s.", + idle_cpus, maybe_cpus, maybe_cpus > 1 ? "s" : ""); + + } + + SAYF(cGRA " <<<" cRST "\n\n"); + return 0; + + } + + if (maybe_cpus) { + + SAYF(cYEL "CAUTION: " cRST "You may still have %u core%s available.", + maybe_cpus, maybe_cpus > 1 ? "s" : ""); + SAYF(cGRA " <<<" cRST "\n\n"); + return 1; + + } + + SAYF(cLRD "FAIL: " cRST "All cores are overbooked."); + SAYF(cGRA " <<<" cRST "\n\n"); + return 2; + +#else + + u32 util_perc; + + SAYF(cCYA "afl-gotcpu " cBRI VERSION cRST " by \n"); + + /* Run a busy loop for CTEST_TARGET_MS. */ + + ACTF("Measuring gross preemption rate (this will take %0.02f sec)...", + ((double)CTEST_TARGET_MS) / 1000); + + util_perc = measure_preemption(CTEST_TARGET_MS); + + /* Deliver the final verdict. */ + + SAYF(cGRA "\n>>> "); + + if (util_perc < 105) { + + SAYF(cLGN "PASS: " cRST "You can probably run additional processes."); + + } else if (util_perc < 130) { + + SAYF(cYEL "CAUTION: " cRST "Your CPU may be somewhat overbooked (%u%%).", + util_perc); + + } else { + + SAYF(cLRD "FAIL: " cRST "Your CPU is overbooked (%u%%).", util_perc); + + } + + SAYF(cGRA " <<<" cRST "\n\n"); + + return (util_perc > 105) + (util_perc > 130); + +#endif /* ^HAVE_AFFINITY */ + +} diff --git a/src/afl-plot b/src/afl-plot new file mode 100644 index 0000000..78825a9 --- /dev/null +++ b/src/afl-plot @@ -0,0 +1,170 @@ +#!/bin/sh +# +# american fuzzy lop - Advanced Persistent Graphing +# ------------------------------------------------- +# +# Written and maintained by Michal Zalewski +# Based on a design & prototype by Michael Rash. +# +# Copyright 2014, 2015 Google LLC All rights reserved. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at: +# +# http://www.apache.org/licenses/LICENSE-2.0 +# + +echo "progress plotting utility for afl-fuzz by " +echo + +if [ ! "$#" = "2" ]; then + + cat 1>&2 <<_EOF_ +This program generates gnuplot images from afl-fuzz output data. Usage: + +$0 afl_state_dir graph_output_dir + +The afl_state_dir parameter should point to an existing state directory for any +active or stopped instance of afl-fuzz; while graph_output_dir should point to +an empty directory where this tool can write the resulting plots to. + +The program will put index.html and three PNG images in the output directory; +you should be able to view it with any web browser of your choice. + +_EOF_ + + exit 1 + +fi + +if [ "$AFL_ALLOW_TMP" = "" ]; then + + echo "$1" | grep -qE '^(/var)?/tmp/' + T1="$?" + + echo "$2" | grep -qE '^(/var)?/tmp/' + T2="$?" + + if [ "$T1" = "0" -o "$T2" = "0" ]; then + + echo "[-] Error: this script shouldn't be used with shared /tmp directories." 1>&2 + exit 1 + + fi + +fi + +if [ ! -f "$1/plot_data" ]; then + + echo "[-] Error: input directory is not valid (missing 'plot_data')." 1>&2 + exit 1 + +fi + +BANNER="`cat "$1/fuzzer_stats" | grep '^afl_banner ' | cut -d: -f2- | cut -b2-`" + +test "$BANNER" = "" && BANNER="(none)" + +GNUPLOT=`which gnuplot 2>/dev/null` + +if [ "$GNUPLOT" = "" ]; then + + echo "[-] Error: can't find 'gnuplot' in your \$PATH." 1>&2 + exit 1 + +fi + +mkdir "$2" 2>/dev/null + +if [ ! -d "$2" ]; then + + echo "[-] Error: unable to create the output directory - pick another location." 1>&2 + exit 1 + +fi + +rm -f "$2/high_freq.png" "$2/low_freq.png" "$2/exec_speed.png" +mv -f "$2/index.html" "$2/index.html.orig" 2>/dev/null + +echo "[*] Generating plots..." + +( + +cat <<_EOF_ +set terminal png truecolor enhanced size 1000,300 butt + +set output '$2/high_freq.png' + +set xdata time +set timefmt '%s' +set format x "%b %d\n%H:%M" +set tics font 'small' +unset mxtics +unset mytics + +set grid xtics linetype 0 linecolor rgb '#e0e0e0' +set grid ytics linetype 0 linecolor rgb '#e0e0e0' +set border linecolor rgb '#50c0f0' +set tics textcolor rgb '#000000' +set key outside + +set autoscale xfixmin +set autoscale xfixmax + +plot '$1/plot_data' using 1:4 with filledcurve x1 title 'total paths' linecolor rgb '#000000' fillstyle transparent solid 0.2 noborder, \\ + '' using 1:3 with filledcurve x1 title 'current path' linecolor rgb '#f0f0f0' fillstyle transparent solid 0.5 noborder, \\ + '' using 1:5 with lines title 'pending paths' linecolor rgb '#0090ff' linewidth 3, \\ + '' using 1:6 with lines title 'pending favs' linecolor rgb '#c00080' linewidth 3, \\ + '' using 1:2 with lines title 'cycles done' linecolor rgb '#c000f0' linewidth 3 + +set terminal png truecolor enhanced size 1000,200 butt +set output '$2/low_freq.png' + +plot '$1/plot_data' using 1:8 with filledcurve x1 title '' linecolor rgb '#c00080' fillstyle transparent solid 0.2 noborder, \\ + '' using 1:8 with lines title ' uniq crashes' linecolor rgb '#c00080' linewidth 3, \\ + '' using 1:9 with lines title 'uniq hangs' linecolor rgb '#c000f0' linewidth 3, \\ + '' using 1:10 with lines title 'levels' linecolor rgb '#0090ff' linewidth 3 + +set terminal png truecolor enhanced size 1000,200 butt +set output '$2/exec_speed.png' + +plot '$1/plot_data' using 1:11 with filledcurve x1 title '' linecolor rgb '#0090ff' fillstyle transparent solid 0.2 noborder, \\ + '$1/plot_data' using 1:11 with lines title ' execs/sec' linecolor rgb '#0090ff' linewidth 3 smooth bezier; + +_EOF_ + +) | gnuplot + +if [ ! -s "$2/exec_speed.png" ]; then + + echo "[-] Error: something went wrong! Perhaps you have an ancient version of gnuplot?" 1>&2 + exit 1 + +fi + +echo "[*] Generating index.html..." + +cat >"$2/index.html" <<_EOF_ + + + + +
Banner:$BANNER
Directory:$1
Generated on:`date`
+

+

+

+ + +_EOF_ + +# Make it easy to remotely view results when outputting directly to a directory +# served by Apache or other HTTP daemon. Since the plots aren't horribly +# sensitive, this seems like a reasonable trade-off. + +chmod 755 "$2" +chmod 644 "$2/high_freq.png" "$2/low_freq.png" "$2/exec_speed.png" "$2/index.html" + +echo "[+] All done - enjoy your charts!" + +exit 0 diff --git a/src/afl-showmap.c b/src/afl-showmap.c new file mode 100644 index 0000000..4af6518 --- /dev/null +++ b/src/afl-showmap.c @@ -0,0 +1,795 @@ +/* + Copyright 2013 Google LLC All rights reserved. + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at: + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +*/ + +/* + american fuzzy lop - map display utility + ---------------------------------------- + + Written and maintained by Michal Zalewski + + A very simple tool that runs the targeted binary and displays + the contents of the trace bitmap in a human-readable form. Useful in + scripts to eliminate redundant inputs and perform other checks. + + Exit code is 2 if the target program crashes; 1 if it times out or + there is a problem executing it; or 0 if execution is successful. +*/ + +#define AFL_MAIN +#include "android-ashmem.h" + +#include "config.h" +#include "types.h" +#include "debug.h" +#include "alloc-inl.h" +#include "hash.h" + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include + +static s32 child_pid; /* PID of the tested program */ + +static u8* trace_bits; /* SHM with instrumentation bitmap */ + +static u8 *out_file, /* Trace output file */ + *doc_path, /* Path to docs */ + *target_path, /* Path to target binary */ + *at_file; /* Substitution string for @@ */ + +static u32 exec_tmout; /* Exec timeout (ms) */ + +static u64 mem_limit = MEM_LIMIT; /* Memory limit (MB) */ + +static s32 shm_id; /* ID of the SHM region */ + +static u8 quiet_mode, /* Hide non-essential messages? */ + edges_only, /* Ignore hit counts? */ + cmin_mode, /* Generate output in afl-cmin mode? */ + binary_mode, /* Write output as a binary map */ + keep_cores; /* Allow coredumps? */ + +static volatile u8 + stop_soon, /* Ctrl-C pressed? */ + child_timed_out, /* Child timed out? */ + child_crashed; /* Child crashed? */ + +/* Classify tuple counts. Instead of mapping to individual bits, as in + afl-fuzz.c, we map to more user-friendly numbers between 1 and 8. */ + +static const u8 count_class_human[256] = { + + [0] = 0, + [1] = 1, + [2] = 2, + [3] = 3, + [4 ... 7] = 4, + [8 ... 15] = 5, + [16 ... 31] = 6, + [32 ... 127] = 7, + [128 ... 255] = 8 + +}; + +static const u8 count_class_binary[256] = { + + [0] = 0, + [1] = 1, + [2] = 2, + [3] = 4, + [4 ... 7] = 8, + [8 ... 15] = 16, + [16 ... 31] = 32, + [32 ... 127] = 64, + [128 ... 255] = 128 + +}; + +static void classify_counts(u8* mem, const u8* map) { + + u32 i = MAP_SIZE; + + if (edges_only) { + + while (i--) { + if (*mem) *mem = 1; + mem++; + } + + } else { + + while (i--) { + *mem = map[*mem]; + mem++; + } + + } + +} + + +/* Get rid of shared memory (atexit handler). */ + +static void remove_shm(void) { + + shmctl(shm_id, IPC_RMID, NULL); + +} + + +/* Configure shared memory. */ + +static void setup_shm(void) { + + u8* shm_str; + + shm_id = shmget(IPC_PRIVATE, MAP_SIZE, IPC_CREAT | IPC_EXCL | 0600); + + if (shm_id < 0) PFATAL("shmget() failed"); + + atexit(remove_shm); + + shm_str = alloc_printf("%d", shm_id); + + setenv(SHM_ENV_VAR, shm_str, 1); + + ck_free(shm_str); + + trace_bits = shmat(shm_id, NULL, 0); + + if (trace_bits == (void *)-1) PFATAL("shmat() failed"); + +} + +/* Write results. */ + +static u32 write_results(void) { + + s32 fd; + u32 i, ret = 0; + + u8 cco = !!getenv("AFL_CMIN_CRASHES_ONLY"), + caa = !!getenv("AFL_CMIN_ALLOW_ANY"); + + if (!strncmp(out_file, "/dev/", 5)) { + + fd = open(out_file, O_WRONLY, 0600); + if (fd < 0) PFATAL("Unable to open '%s'", out_file); + + } else if (!strcmp(out_file, "-")) { + + fd = dup(1); + if (fd < 0) PFATAL("Unable to open stdout"); + + } else { + + unlink(out_file); /* Ignore errors */ + fd = open(out_file, O_WRONLY | O_CREAT | O_EXCL, 0600); + if (fd < 0) PFATAL("Unable to create '%s'", out_file); + + } + + + if (binary_mode) { + + for (i = 0; i < MAP_SIZE; i++) + if (trace_bits[i]) ret++; + + ck_write(fd, trace_bits, MAP_SIZE, out_file); + close(fd); + + } else { + + FILE* f = fdopen(fd, "w"); + + if (!f) PFATAL("fdopen() failed"); + + for (i = 0; i < MAP_SIZE; i++) { + + if (!trace_bits[i]) continue; + ret++; + + if (cmin_mode) { + + if (child_timed_out) break; + if (!caa && child_crashed != cco) break; + + fprintf(f, "%u%u\n", trace_bits[i], i); + + } else fprintf(f, "%06u:%u\n", i, trace_bits[i]); + + } + + fclose(f); + + } + + return ret; + +} + + +/* Handle timeout signal. */ + +static void handle_timeout(int sig) { + + child_timed_out = 1; + if (child_pid > 0) kill(child_pid, SIGKILL); + +} + + +/* Execute target application. */ + +static void run_target(char** argv) { + + static struct itimerval it; + int status = 0; + + if (!quiet_mode) + SAYF("-- Program output begins --\n" cRST); + + MEM_BARRIER(); + + child_pid = fork(); + + if (child_pid < 0) PFATAL("fork() failed"); + + if (!child_pid) { + + struct rlimit r; + + if (quiet_mode) { + + s32 fd = open("/dev/null", O_RDWR); + + if (fd < 0 || dup2(fd, 1) < 0 || dup2(fd, 2) < 0) { + *(u32*)trace_bits = EXEC_FAIL_SIG; + PFATAL("Descriptor initialization failed"); + } + + close(fd); + + } + + if (mem_limit) { + + r.rlim_max = r.rlim_cur = ((rlim_t)mem_limit) << 20; + +#ifdef RLIMIT_AS + + setrlimit(RLIMIT_AS, &r); /* Ignore errors */ + +#else + + setrlimit(RLIMIT_DATA, &r); /* Ignore errors */ + +#endif /* ^RLIMIT_AS */ + + } + + if (!keep_cores) r.rlim_max = r.rlim_cur = 0; + else r.rlim_max = r.rlim_cur = RLIM_INFINITY; + + setrlimit(RLIMIT_CORE, &r); /* Ignore errors */ + + if (!getenv("LD_BIND_LAZY")) setenv("LD_BIND_NOW", "1", 0); + + setsid(); + + execv(target_path, argv); + + *(u32*)trace_bits = EXEC_FAIL_SIG; + exit(0); + + } + + /* Configure timeout, wait for child, cancel timeout. */ + + if (exec_tmout) { + + child_timed_out = 0; + it.it_value.tv_sec = (exec_tmout / 1000); + it.it_value.tv_usec = (exec_tmout % 1000) * 1000; + + } + + setitimer(ITIMER_REAL, &it, NULL); + + if (waitpid(child_pid, &status, 0) <= 0) FATAL("waitpid() failed"); + + child_pid = 0; + it.it_value.tv_sec = 0; + it.it_value.tv_usec = 0; + setitimer(ITIMER_REAL, &it, NULL); + + MEM_BARRIER(); + + /* Clean up bitmap, analyze exit condition, etc. */ + + if (*(u32*)trace_bits == EXEC_FAIL_SIG) + FATAL("Unable to execute '%s'", argv[0]); + + classify_counts(trace_bits, binary_mode ? + count_class_binary : count_class_human); + + if (!quiet_mode) + SAYF(cRST "-- Program output ends --\n"); + + if (!child_timed_out && !stop_soon && WIFSIGNALED(status)) + child_crashed = 1; + + if (!quiet_mode) { + + if (child_timed_out) + SAYF(cLRD "\n+++ Program timed off +++\n" cRST); + else if (stop_soon) + SAYF(cLRD "\n+++ Program aborted by user +++\n" cRST); + else if (child_crashed) + SAYF(cLRD "\n+++ Program killed by signal %u +++\n" cRST, WTERMSIG(status)); + + } + + +} + + +/* Handle Ctrl-C and the like. */ + +static void handle_stop_sig(int sig) { + + stop_soon = 1; + + if (child_pid > 0) kill(child_pid, SIGKILL); + +} + + +/* Do basic preparations - persistent fds, filenames, etc. */ + +static void set_up_environment(void) { + + setenv("ASAN_OPTIONS", "abort_on_error=1:" + "detect_leaks=0:" + "symbolize=0:" + "allocator_may_return_null=1", 0); + + setenv("MSAN_OPTIONS", "exit_code=" STRINGIFY(MSAN_ERROR) ":" + "symbolize=0:" + "abort_on_error=1:" + "allocator_may_return_null=1:" + "msan_track_origins=0", 0); + + if (getenv("AFL_PRELOAD")) { + setenv("LD_PRELOAD", getenv("AFL_PRELOAD"), 1); + setenv("DYLD_INSERT_LIBRARIES", getenv("AFL_PRELOAD"), 1); + } + +} + + +/* Setup signal handlers, duh. */ + +static void setup_signal_handlers(void) { + + struct sigaction sa; + + sa.sa_handler = NULL; + sa.sa_flags = SA_RESTART; + sa.sa_sigaction = NULL; + + sigemptyset(&sa.sa_mask); + + /* Various ways of saying "stop". */ + + sa.sa_handler = handle_stop_sig; + sigaction(SIGHUP, &sa, NULL); + sigaction(SIGINT, &sa, NULL); + sigaction(SIGTERM, &sa, NULL); + + /* Exec timeout notifications. */ + + sa.sa_handler = handle_timeout; + sigaction(SIGALRM, &sa, NULL); + +} + + +/* Detect @@ in args. */ + +static void detect_file_args(char** argv) { + + u32 i = 0; + u8* cwd = getcwd(NULL, 0); + + if (!cwd) PFATAL("getcwd() failed"); + + while (argv[i]) { + + u8* aa_loc = strstr(argv[i], "@@"); + + if (aa_loc) { + + u8 *aa_subst, *n_arg; + + if (!at_file) FATAL("@@ syntax is not supported by this tool."); + + /* Be sure that we're always using fully-qualified paths. */ + + if (at_file[0] == '/') aa_subst = at_file; + else aa_subst = alloc_printf("%s/%s", cwd, at_file); + + /* Construct a replacement argv value. */ + + *aa_loc = 0; + n_arg = alloc_printf("%s%s%s", argv[i], aa_subst, aa_loc + 2); + argv[i] = n_arg; + *aa_loc = '@'; + + if (at_file[0] != '/') ck_free(aa_subst); + + } + + i++; + + } + + free(cwd); /* not tracked */ + +} + + +/* Show banner. */ + +static void show_banner(void) { + + SAYF(cCYA "afl-showmap " cBRI VERSION cRST " by \n"); + +} + +/* Display usage hints. */ + +static void usage(u8* argv0) { + + show_banner(); + + SAYF("\n%s [ options ] -- /path/to/target_app [ ... ]\n\n" + + "Required parameters:\n\n" + + " -o file - file to write the trace data to\n\n" + + "Execution control settings:\n\n" + + " -t msec - timeout for each run (none)\n" + " -m megs - memory limit for child process (%u MB)\n" + " -Q - use binary-only instrumentation (QEMU mode)\n\n" + + "Other settings:\n\n" + + " -q - sink program's output and don't show messages\n" + " -e - show edge coverage only, ignore hit counts\n" + " -c - allow core dumps\n" + " -V - show version number and exit\n\n" + + "This tool displays raw tuple data captured by AFL instrumentation.\n" + "For additional help, consult %s/README.\n\n" cRST, + + argv0, MEM_LIMIT, doc_path); + + exit(1); + +} + + +/* Find binary. */ + +static void find_binary(u8* fname) { + + u8* env_path = 0; + struct stat st; + + if (strchr(fname, '/') || !(env_path = getenv("PATH"))) { + + target_path = ck_strdup(fname); + + if (stat(target_path, &st) || !S_ISREG(st.st_mode) || + !(st.st_mode & 0111) || st.st_size < 4) + FATAL("Program '%s' not found or not executable", fname); + + } else { + + while (env_path) { + + u8 *cur_elem, *delim = strchr(env_path, ':'); + + if (delim) { + + cur_elem = ck_alloc(delim - env_path + 1); + memcpy(cur_elem, env_path, delim - env_path); + delim++; + + } else cur_elem = ck_strdup(env_path); + + env_path = delim; + + if (cur_elem[0]) + target_path = alloc_printf("%s/%s", cur_elem, fname); + else + target_path = ck_strdup(fname); + + ck_free(cur_elem); + + if (!stat(target_path, &st) && S_ISREG(st.st_mode) && + (st.st_mode & 0111) && st.st_size >= 4) break; + + ck_free(target_path); + target_path = 0; + + } + + if (!target_path) FATAL("Program '%s' not found or not executable", fname); + + } + +} + + +/* Fix up argv for QEMU. */ + +static char** get_qemu_argv(u8* own_loc, char** argv, int argc) { + + char** new_argv = ck_alloc(sizeof(char*) * (argc + 4)); + u8 *tmp, *cp, *rsl, *own_copy; + + /* Workaround for a QEMU stability glitch. */ + + setenv("QEMU_LOG", "nochain", 1); + + memcpy(new_argv + 3, argv + 1, sizeof(char*) * argc); + + new_argv[2] = target_path; + new_argv[1] = "--"; + + /* Now we need to actually find qemu for argv[0]. */ + + tmp = getenv("AFL_PATH"); + + if (tmp) { + + cp = alloc_printf("%s/afl-qemu-trace", tmp); + + if (access(cp, X_OK)) + FATAL("Unable to find '%s'", tmp); + + target_path = new_argv[0] = cp; + return new_argv; + + } + + own_copy = ck_strdup(own_loc); + rsl = strrchr(own_copy, '/'); + + if (rsl) { + + *rsl = 0; + + cp = alloc_printf("%s/afl-qemu-trace", own_copy); + ck_free(own_copy); + + if (!access(cp, X_OK)) { + + target_path = new_argv[0] = cp; + return new_argv; + + } + + } else ck_free(own_copy); + + if (!access(BIN_PATH "/afl-qemu-trace", X_OK)) { + + target_path = new_argv[0] = BIN_PATH "/afl-qemu-trace"; + return new_argv; + + } + + FATAL("Unable to find 'afl-qemu-trace'."); + +} + + +/* Main entry point */ + +int main(int argc, char** argv) { + + s32 opt; + u8 mem_limit_given = 0, timeout_given = 0, qemu_mode = 0; + u32 tcnt; + char** use_argv; + + doc_path = access(DOC_PATH, F_OK) ? "docs" : DOC_PATH; + + while ((opt = getopt(argc,argv,"+o:m:t:A:eqZQbcV")) > 0) + + switch (opt) { + + case 'o': + + if (out_file) FATAL("Multiple -o options not supported"); + out_file = optarg; + break; + + case 'm': { + + u8 suffix = 'M'; + + if (mem_limit_given) FATAL("Multiple -m options not supported"); + mem_limit_given = 1; + + if (!strcmp(optarg, "none")) { + + mem_limit = 0; + break; + + } + + if (sscanf(optarg, "%llu%c", &mem_limit, &suffix) < 1 || + optarg[0] == '-') FATAL("Bad syntax used for -m"); + + switch (suffix) { + + case 'T': mem_limit *= 1024 * 1024; break; + case 'G': mem_limit *= 1024; break; + case 'k': mem_limit /= 1024; break; + case 'M': break; + + default: FATAL("Unsupported suffix or bad syntax for -m"); + + } + + if (mem_limit < 5) FATAL("Dangerously low value of -m"); + + if (sizeof(rlim_t) == 4 && mem_limit > 2000) + FATAL("Value of -m out of range on 32-bit systems"); + + } + + break; + + case 't': + + if (timeout_given) FATAL("Multiple -t options not supported"); + timeout_given = 1; + + if (strcmp(optarg, "none")) { + exec_tmout = atoi(optarg); + + if (exec_tmout < 20 || optarg[0] == '-') + FATAL("Dangerously low value of -t"); + + } + + break; + + case 'e': + + if (edges_only) FATAL("Multiple -e options not supported"); + edges_only = 1; + break; + + case 'q': + + if (quiet_mode) FATAL("Multiple -q options not supported"); + quiet_mode = 1; + break; + + case 'Z': + + /* This is an undocumented option to write data in the syntax expected + by afl-cmin. Nobody else should have any use for this. */ + + cmin_mode = 1; + quiet_mode = 1; + break; + + case 'A': + + /* Another afl-cmin specific feature. */ + at_file = optarg; + break; + + case 'Q': + + if (qemu_mode) FATAL("Multiple -Q options not supported"); + if (!mem_limit_given) mem_limit = MEM_LIMIT_QEMU; + + qemu_mode = 1; + break; + + case 'b': + + /* Secret undocumented mode. Writes output in raw binary format + similar to that dumped by afl-fuzz in + + A simple test case minimizer that takes an input file and tries to remove + as much data as possible while keeping the binary in a crashing state + *or* producing consistent instrumentation output (the mode is auto-selected + based on the initially observed behavior). +*/ + +#define AFL_MAIN +#include "android-ashmem.h" + +#include "config.h" +#include "types.h" +#include "debug.h" +#include "alloc-inl.h" +#include "hash.h" + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include + +static s32 child_pid; /* PID of the tested program */ + +static u8 *trace_bits, /* SHM with instrumentation bitmap */ + *mask_bitmap; /* Mask for trace bits (-B) */ + +static u8 *in_file, /* Minimizer input test case */ + *out_file, /* Minimizer output file */ + *prog_in, /* Targeted program input file */ + *target_path, /* Path to target binary */ + *doc_path; /* Path to docs */ + +static u8* in_data; /* Input data for trimming */ + +static u32 in_len, /* Input data length */ + orig_cksum, /* Original checksum */ + total_execs, /* Total number of execs */ + missed_hangs, /* Misses due to hangs */ + missed_crashes, /* Misses due to crashes */ + missed_paths, /* Misses due to exec path diffs */ + exec_tmout = EXEC_TIMEOUT; /* Exec timeout (ms) */ + +static u64 mem_limit = MEM_LIMIT; /* Memory limit (MB) */ + +static s32 shm_id, /* ID of the SHM region */ + dev_null_fd = -1; /* FD to /dev/null */ + +static u8 crash_mode, /* Crash-centric mode? */ + exit_crash, /* Treat non-zero exit as crash? */ + edges_only, /* Ignore hit counts? */ + exact_mode, /* Require path match for crashes? */ + use_stdin = 1; /* Use stdin for program input? */ + +static volatile u8 + stop_soon, /* Ctrl-C pressed? */ + child_timed_out; /* Child timed out? */ + + +/* Classify tuple counts. This is a slow & naive version, but good enough here. */ + +static const u8 count_class_lookup[256] = { + + [0] = 0, + [1] = 1, + [2] = 2, + [3] = 4, + [4 ... 7] = 8, + [8 ... 15] = 16, + [16 ... 31] = 32, + [32 ... 127] = 64, + [128 ... 255] = 128 + +}; + +static void classify_counts(u8* mem) { + + u32 i = MAP_SIZE; + + if (edges_only) { + + while (i--) { + if (*mem) *mem = 1; + mem++; + } + + } else { + + while (i--) { + *mem = count_class_lookup[*mem]; + mem++; + } + + } + +} + + +/* Apply mask to classified bitmap (if set). */ + +static void apply_mask(u32* mem, u32* mask) { + + u32 i = (MAP_SIZE >> 2); + + if (!mask) return; + + while (i--) { + + *mem &= ~*mask; + mem++; + mask++; + + } + +} + + +/* See if any bytes are set in the bitmap. */ + +static inline u8 anything_set(void) { + + u32* ptr = (u32*)trace_bits; + u32 i = (MAP_SIZE >> 2); + + while (i--) if (*(ptr++)) return 1; + + return 0; + +} + + + +/* Get rid of shared memory and temp files (atexit handler). */ + +static void remove_shm(void) { + + if (prog_in) unlink(prog_in); /* Ignore errors */ + shmctl(shm_id, IPC_RMID, NULL); + +} + + +/* Configure shared memory. */ + +static void setup_shm(void) { + + u8* shm_str; + + shm_id = shmget(IPC_PRIVATE, MAP_SIZE, IPC_CREAT | IPC_EXCL | 0600); + + if (shm_id < 0) PFATAL("shmget() failed"); + + atexit(remove_shm); + + shm_str = alloc_printf("%d", shm_id); + + setenv(SHM_ENV_VAR, shm_str, 1); + + ck_free(shm_str); + + trace_bits = shmat(shm_id, NULL, 0); + + if (trace_bits == (void *)-1) PFATAL("shmat() failed"); + +} + + +/* Read initial file. */ + +static void read_initial_file(void) { + + struct stat st; + s32 fd = open(in_file, O_RDONLY); + + if (fd < 0) PFATAL("Unable to open '%s'", in_file); + + if (fstat(fd, &st) || !st.st_size) + FATAL("Zero-sized input file."); + + if (st.st_size >= TMIN_MAX_FILE) + FATAL("Input file is too large (%u MB max)", TMIN_MAX_FILE / 1024 / 1024); + + in_len = st.st_size; + in_data = ck_alloc_nozero(in_len); + + ck_read(fd, in_data, in_len, in_file); + + close(fd); + + OKF("Read %u byte%s from '%s'.", in_len, in_len == 1 ? "" : "s", in_file); + +} + + +/* Write output file. */ + +static s32 write_to_file(u8* path, u8* mem, u32 len) { + + s32 ret; + + unlink(path); /* Ignore errors */ + + ret = open(path, O_RDWR | O_CREAT | O_EXCL, 0600); + + if (ret < 0) PFATAL("Unable to create '%s'", path); + + ck_write(ret, mem, len, path); + + lseek(ret, 0, SEEK_SET); + + return ret; + +} + + +/* Handle timeout signal. */ + +static void handle_timeout(int sig) { + + child_timed_out = 1; + if (child_pid > 0) kill(child_pid, SIGKILL); + +} + + +/* Execute target application. Returns 0 if the changes are a dud, or + 1 if they should be kept. */ + +static u8 run_target(char** argv, u8* mem, u32 len, u8 first_run) { + + static struct itimerval it; + int status = 0; + + s32 prog_in_fd; + u32 cksum; + + memset(trace_bits, 0, MAP_SIZE); + MEM_BARRIER(); + + prog_in_fd = write_to_file(prog_in, mem, len); + + child_pid = fork(); + + if (child_pid < 0) PFATAL("fork() failed"); + + if (!child_pid) { + + struct rlimit r; + + if (dup2(use_stdin ? prog_in_fd : dev_null_fd, 0) < 0 || + dup2(dev_null_fd, 1) < 0 || + dup2(dev_null_fd, 2) < 0) { + + *(u32*)trace_bits = EXEC_FAIL_SIG; + PFATAL("dup2() failed"); + + } + + close(dev_null_fd); + close(prog_in_fd); + + setsid(); + + if (mem_limit) { + + r.rlim_max = r.rlim_cur = ((rlim_t)mem_limit) << 20; + +#ifdef RLIMIT_AS + + setrlimit(RLIMIT_AS, &r); /* Ignore errors */ + +#else + + setrlimit(RLIMIT_DATA, &r); /* Ignore errors */ + +#endif /* ^RLIMIT_AS */ + + } + + r.rlim_max = r.rlim_cur = 0; + setrlimit(RLIMIT_CORE, &r); /* Ignore errors */ + + execv(target_path, argv); + + *(u32*)trace_bits = EXEC_FAIL_SIG; + exit(0); + + } + + close(prog_in_fd); + + /* Configure timeout, wait for child, cancel timeout. */ + + child_timed_out = 0; + it.it_value.tv_sec = (exec_tmout / 1000); + it.it_value.tv_usec = (exec_tmout % 1000) * 1000; + + setitimer(ITIMER_REAL, &it, NULL); + + if (waitpid(child_pid, &status, 0) <= 0) FATAL("waitpid() failed"); + + child_pid = 0; + it.it_value.tv_sec = 0; + it.it_value.tv_usec = 0; + + setitimer(ITIMER_REAL, &it, NULL); + + MEM_BARRIER(); + + /* Clean up bitmap, analyze exit condition, etc. */ + + if (*(u32*)trace_bits == EXEC_FAIL_SIG) + FATAL("Unable to execute '%s'", argv[0]); + + classify_counts(trace_bits); + apply_mask((u32*)trace_bits, (u32*)mask_bitmap); + total_execs++; + + if (stop_soon) { + + SAYF(cRST cLRD "\n+++ Minimization aborted by user +++\n" cRST); + close(write_to_file(out_file, in_data, in_len)); + exit(1); + + } + + /* Always discard inputs that time out. */ + + if (child_timed_out) { + + missed_hangs++; + return 0; + + } + + /* Handle crashing inputs depending on current mode. */ + + if (WIFSIGNALED(status) || + (WIFEXITED(status) && WEXITSTATUS(status) == MSAN_ERROR) || + (WIFEXITED(status) && WEXITSTATUS(status) && exit_crash)) { + + if (first_run) crash_mode = 1; + + if (crash_mode) { + + if (!exact_mode) return 1; + + } else { + + missed_crashes++; + return 0; + + } + + } else + + /* Handle non-crashing inputs appropriately. */ + + if (crash_mode) { + + missed_paths++; + return 0; + + } + + cksum = hash32(trace_bits, MAP_SIZE, HASH_CONST); + + if (first_run) orig_cksum = cksum; + + if (orig_cksum == cksum) return 1; + + missed_paths++; + return 0; + +} + + +/* Find first power of two greater or equal to val. */ + +static u32 next_p2(u32 val) { + + u32 ret = 1; + while (val > ret) ret <<= 1; + return ret; + +} + + +/* Actually minimize! */ + +static void minimize(char** argv) { + + static u32 alpha_map[256]; + + u8* tmp_buf = ck_alloc_nozero(in_len); + u32 orig_len = in_len, stage_o_len; + + u32 del_len, set_len, del_pos, set_pos, i, alpha_size, cur_pass = 0; + u32 syms_removed, alpha_del0 = 0, alpha_del1, alpha_del2, alpha_d_total = 0; + u8 changed_any, prev_del; + + /*********************** + * BLOCK NORMALIZATION * + ***********************/ + + set_len = next_p2(in_len / TMIN_SET_STEPS); + set_pos = 0; + + if (set_len < TMIN_SET_MIN_SIZE) set_len = TMIN_SET_MIN_SIZE; + + ACTF(cBRI "Stage #0: " cRST "One-time block normalization..."); + + while (set_pos < in_len) { + + u8 res; + u32 use_len = MIN(set_len, in_len - set_pos); + + for (i = 0; i < use_len; i++) + if (in_data[set_pos + i] != '0') break; + + if (i != use_len) { + + memcpy(tmp_buf, in_data, in_len); + memset(tmp_buf + set_pos, '0', use_len); + + res = run_target(argv, tmp_buf, in_len, 0); + + if (res) { + + memset(in_data + set_pos, '0', use_len); + changed_any = 1; + alpha_del0 += use_len; + + } + + } + + set_pos += set_len; + + } + + alpha_d_total += alpha_del0; + + OKF("Block normalization complete, %u byte%s replaced.", alpha_del0, + alpha_del0 == 1 ? "" : "s"); + +next_pass: + + ACTF(cYEL "--- " cBRI "Pass #%u " cYEL "---", ++cur_pass); + changed_any = 0; + + /****************** + * BLOCK DELETION * + ******************/ + + del_len = next_p2(in_len / TRIM_START_STEPS); + stage_o_len = in_len; + + ACTF(cBRI "Stage #1: " cRST "Removing blocks of data..."); + +next_del_blksize: + + if (!del_len) del_len = 1; + del_pos = 0; + prev_del = 1; + + SAYF(cGRA " Block length = %u, remaining size = %u\n" cRST, + del_len, in_len); + + while (del_pos < in_len) { + + u8 res; + s32 tail_len; + + tail_len = in_len - del_pos - del_len; + if (tail_len < 0) tail_len = 0; + + /* If we have processed at least one full block (initially, prev_del == 1), + and we did so without deleting the previous one, and we aren't at the + very end of the buffer (tail_len > 0), and the current block is the same + as the previous one... skip this step as a no-op. */ + + if (!prev_del && tail_len && !memcmp(in_data + del_pos - del_len, + in_data + del_pos, del_len)) { + + del_pos += del_len; + continue; + + } + + prev_del = 0; + + /* Head */ + memcpy(tmp_buf, in_data, del_pos); + + /* Tail */ + memcpy(tmp_buf + del_pos, in_data + del_pos + del_len, tail_len); + + res = run_target(argv, tmp_buf, del_pos + tail_len, 0); + + if (res) { + + memcpy(in_data, tmp_buf, del_pos + tail_len); + prev_del = 1; + in_len = del_pos + tail_len; + + changed_any = 1; + + } else del_pos += del_len; + + } + + if (del_len > 1 && in_len >= 1) { + + del_len /= 2; + goto next_del_blksize; + + } + + OKF("Block removal complete, %u bytes deleted.", stage_o_len - in_len); + + if (!in_len && changed_any) + WARNF(cLRD "Down to zero bytes - check the command line and mem limit!" cRST); + + if (cur_pass > 1 && !changed_any) goto finalize_all; + + /************************* + * ALPHABET MINIMIZATION * + *************************/ + + alpha_size = 0; + alpha_del1 = 0; + syms_removed = 0; + + memset(alpha_map, 0, 256 * sizeof(u32)); + + for (i = 0; i < in_len; i++) { + if (!alpha_map[in_data[i]]) alpha_size++; + alpha_map[in_data[i]]++; + } + + ACTF(cBRI "Stage #2: " cRST "Minimizing symbols (%u code point%s)...", + alpha_size, alpha_size == 1 ? "" : "s"); + + for (i = 0; i < 256; i++) { + + u32 r; + u8 res; + + if (i == '0' || !alpha_map[i]) continue; + + memcpy(tmp_buf, in_data, in_len); + + for (r = 0; r < in_len; r++) + if (tmp_buf[r] == i) tmp_buf[r] = '0'; + + res = run_target(argv, tmp_buf, in_len, 0); + + if (res) { + + memcpy(in_data, tmp_buf, in_len); + syms_removed++; + alpha_del1 += alpha_map[i]; + changed_any = 1; + + } + + } + + alpha_d_total += alpha_del1; + + OKF("Symbol minimization finished, %u symbol%s (%u byte%s) replaced.", + syms_removed, syms_removed == 1 ? "" : "s", + alpha_del1, alpha_del1 == 1 ? "" : "s"); + + /************************** + * CHARACTER MINIMIZATION * + **************************/ + + alpha_del2 = 0; + + ACTF(cBRI "Stage #3: " cRST "Character minimization..."); + + memcpy(tmp_buf, in_data, in_len); + + for (i = 0; i < in_len; i++) { + + u8 res, orig = tmp_buf[i]; + + if (orig == '0') continue; + tmp_buf[i] = '0'; + + res = run_target(argv, tmp_buf, in_len, 0); + + if (res) { + + in_data[i] = '0'; + alpha_del2++; + changed_any = 1; + + } else tmp_buf[i] = orig; + + } + + alpha_d_total += alpha_del2; + + OKF("Character minimization done, %u byte%s replaced.", + alpha_del2, alpha_del2 == 1 ? "" : "s"); + + if (changed_any) goto next_pass; + +finalize_all: + + SAYF("\n" + cGRA " File size reduced by : " cRST "%0.02f%% (to %u byte%s)\n" + cGRA " Characters simplified : " cRST "%0.02f%%\n" + cGRA " Number of execs done : " cRST "%u\n" + cGRA " Fruitless execs : " cRST "path=%u crash=%u hang=%s%u\n\n", + 100 - ((double)in_len) * 100 / orig_len, in_len, in_len == 1 ? "" : "s", + ((double)(alpha_d_total)) * 100 / (in_len ? in_len : 1), + total_execs, missed_paths, missed_crashes, missed_hangs ? cLRD : "", + missed_hangs); + + if (total_execs > 50 && missed_hangs * 10 > total_execs) + WARNF(cLRD "Frequent timeouts - results may be skewed." cRST); + +} + + + +/* Handle Ctrl-C and the like. */ + +static void handle_stop_sig(int sig) { + + stop_soon = 1; + + if (child_pid > 0) kill(child_pid, SIGKILL); + +} + + +/* Do basic preparations - persistent fds, filenames, etc. */ + +static void set_up_environment(void) { + + u8* x; + + dev_null_fd = open("/dev/null", O_RDWR); + if (dev_null_fd < 0) PFATAL("Unable to open /dev/null"); + + if (!prog_in) { + + u8* use_dir = "."; + + if (access(use_dir, R_OK | W_OK | X_OK)) { + + use_dir = getenv("TMPDIR"); + if (!use_dir) use_dir = "/tmp"; + + } + + prog_in = alloc_printf("%s/.afl-tmin-temp-%u", use_dir, getpid()); + + } + + /* Set sane defaults... */ + + x = getenv("ASAN_OPTIONS"); + + if (x) { + + if (!strstr(x, "abort_on_error=1")) + FATAL("Custom ASAN_OPTIONS set without abort_on_error=1 - please fix!"); + + if (!strstr(x, "symbolize=0")) + FATAL("Custom ASAN_OPTIONS set without symbolize=0 - please fix!"); + + } + + x = getenv("MSAN_OPTIONS"); + + if (x) { + + if (!strstr(x, "exit_code=" STRINGIFY(MSAN_ERROR))) + FATAL("Custom MSAN_OPTIONS set without exit_code=" + STRINGIFY(MSAN_ERROR) " - please fix!"); + + if (!strstr(x, "symbolize=0")) + FATAL("Custom MSAN_OPTIONS set without symbolize=0 - please fix!"); + + } + + setenv("ASAN_OPTIONS", "abort_on_error=1:" + "detect_leaks=0:" + "symbolize=0:" + "allocator_may_return_null=1", 0); + + setenv("MSAN_OPTIONS", "exit_code=" STRINGIFY(MSAN_ERROR) ":" + "symbolize=0:" + "abort_on_error=1:" + "allocator_may_return_null=1:" + "msan_track_origins=0", 0); + + if (getenv("AFL_PRELOAD")) { + setenv("LD_PRELOAD", getenv("AFL_PRELOAD"), 1); + setenv("DYLD_INSERT_LIBRARIES", getenv("AFL_PRELOAD"), 1); + } + +} + + +/* Setup signal handlers, duh. */ + +static void setup_signal_handlers(void) { + + struct sigaction sa; + + sa.sa_handler = NULL; + sa.sa_flags = SA_RESTART; + sa.sa_sigaction = NULL; + + sigemptyset(&sa.sa_mask); + + /* Various ways of saying "stop". */ + + sa.sa_handler = handle_stop_sig; + sigaction(SIGHUP, &sa, NULL); + sigaction(SIGINT, &sa, NULL); + sigaction(SIGTERM, &sa, NULL); + + /* Exec timeout notifications. */ + + sa.sa_handler = handle_timeout; + sigaction(SIGALRM, &sa, NULL); + +} + + +/* Detect @@ in args. */ + +static void detect_file_args(char** argv) { + + u32 i = 0; + u8* cwd = getcwd(NULL, 0); + + if (!cwd) PFATAL("getcwd() failed"); + + while (argv[i]) { + + u8* aa_loc = strstr(argv[i], "@@"); + + if (aa_loc) { + + u8 *aa_subst, *n_arg; + + /* Be sure that we're always using fully-qualified paths. */ + + if (prog_in[0] == '/') aa_subst = prog_in; + else aa_subst = alloc_printf("%s/%s", cwd, prog_in); + + /* Construct a replacement argv value. */ + + *aa_loc = 0; + n_arg = alloc_printf("%s%s%s", argv[i], aa_subst, aa_loc + 2); + argv[i] = n_arg; + *aa_loc = '@'; + + if (prog_in[0] != '/') ck_free(aa_subst); + + } + + i++; + + } + + free(cwd); /* not tracked */ + +} + + +/* Display usage hints. */ + +static void usage(u8* argv0) { + + SAYF("\n%s [ options ] -- /path/to/target_app [ ... ]\n\n" + + "Required parameters:\n\n" + + " -i file - input test case to be shrunk by the tool\n" + " -o file - final output location for the minimized data\n\n" + + "Execution control settings:\n\n" + + " -f file - input file read by the tested program (stdin)\n" + " -t msec - timeout for each run (%u ms)\n" + " -m megs - memory limit for child process (%u MB)\n" + " -Q - use binary-only instrumentation (QEMU mode)\n\n" + + "Minimization settings:\n\n" + + " -e - solve for edge coverage only, ignore hit counts\n" + " -x - treat non-zero exit codes as crashes\n\n" + + "Other stuff:\n\n" + + " -V - show version number and exit\n\n" + + "For additional tips, please consult %s/README.\n\n", + + argv0, EXEC_TIMEOUT, MEM_LIMIT, doc_path); + + exit(1); + +} + + +/* Find binary. */ + +static void find_binary(u8* fname) { + + u8* env_path = 0; + struct stat st; + + if (strchr(fname, '/') || !(env_path = getenv("PATH"))) { + + target_path = ck_strdup(fname); + + if (stat(target_path, &st) || !S_ISREG(st.st_mode) || + !(st.st_mode & 0111) || st.st_size < 4) + FATAL("Program '%s' not found or not executable", fname); + + } else { + + while (env_path) { + + u8 *cur_elem, *delim = strchr(env_path, ':'); + + if (delim) { + + cur_elem = ck_alloc(delim - env_path + 1); + memcpy(cur_elem, env_path, delim - env_path); + delim++; + + } else cur_elem = ck_strdup(env_path); + + env_path = delim; + + if (cur_elem[0]) + target_path = alloc_printf("%s/%s", cur_elem, fname); + else + target_path = ck_strdup(fname); + + ck_free(cur_elem); + + if (!stat(target_path, &st) && S_ISREG(st.st_mode) && + (st.st_mode & 0111) && st.st_size >= 4) break; + + ck_free(target_path); + target_path = 0; + + } + + if (!target_path) FATAL("Program '%s' not found or not executable", fname); + + } + +} + + +/* Fix up argv for QEMU. */ + +static char** get_qemu_argv(u8* own_loc, char** argv, int argc) { + + char** new_argv = ck_alloc(sizeof(char*) * (argc + 4)); + u8 *tmp, *cp, *rsl, *own_copy; + + /* Workaround for a QEMU stability glitch. */ + + setenv("QEMU_LOG", "nochain", 1); + + memcpy(new_argv + 3, argv + 1, sizeof(char*) * argc); + + /* Now we need to actually find qemu for argv[0]. */ + + new_argv[2] = target_path; + new_argv[1] = "--"; + + tmp = getenv("AFL_PATH"); + + if (tmp) { + + cp = alloc_printf("%s/afl-qemu-trace", tmp); + + if (access(cp, X_OK)) + FATAL("Unable to find '%s'", tmp); + + target_path = new_argv[0] = cp; + return new_argv; + + } + + own_copy = ck_strdup(own_loc); + rsl = strrchr(own_copy, '/'); + + if (rsl) { + + *rsl = 0; + + cp = alloc_printf("%s/afl-qemu-trace", own_copy); + ck_free(own_copy); + + if (!access(cp, X_OK)) { + + target_path = new_argv[0] = cp; + return new_argv; + + } + + } else ck_free(own_copy); + + if (!access(BIN_PATH "/afl-qemu-trace", X_OK)) { + + target_path = new_argv[0] = BIN_PATH "/afl-qemu-trace"; + return new_argv; + + } + + FATAL("Unable to find 'afl-qemu-trace'."); + +} + + +/* Read mask bitmap from file. This is for the -B option. */ + +static void read_bitmap(u8* fname) { + + s32 fd = open(fname, O_RDONLY); + + if (fd < 0) PFATAL("Unable to open '%s'", fname); + + ck_read(fd, mask_bitmap, MAP_SIZE, fname); + + close(fd); + +} + + + +/* Main entry point */ + +int main(int argc, char** argv) { + + s32 opt; + u8 mem_limit_given = 0, timeout_given = 0, qemu_mode = 0; + char** use_argv; + + doc_path = access(DOC_PATH, F_OK) ? "docs" : DOC_PATH; + + SAYF(cCYA "afl-tmin " cBRI VERSION cRST " by \n"); + + while ((opt = getopt(argc,argv,"+i:o:f:m:t:B:xeQV")) > 0) + + switch (opt) { + + case 'i': + + if (in_file) FATAL("Multiple -i options not supported"); + in_file = optarg; + break; + + case 'o': + + if (out_file) FATAL("Multiple -o options not supported"); + out_file = optarg; + break; + + case 'f': + + if (prog_in) FATAL("Multiple -f options not supported"); + use_stdin = 0; + prog_in = optarg; + break; + + case 'e': + + if (edges_only) FATAL("Multiple -e options not supported"); + edges_only = 1; + break; + + case 'x': + + if (exit_crash) FATAL("Multiple -x options not supported"); + exit_crash = 1; + break; + + case 'm': { + + u8 suffix = 'M'; + + if (mem_limit_given) FATAL("Multiple -m options not supported"); + mem_limit_given = 1; + + if (!strcmp(optarg, "none")) { + + mem_limit = 0; + break; + + } + + if (sscanf(optarg, "%llu%c", &mem_limit, &suffix) < 1 || + optarg[0] == '-') FATAL("Bad syntax used for -m"); + + switch (suffix) { + + case 'T': mem_limit *= 1024 * 1024; break; + case 'G': mem_limit *= 1024; break; + case 'k': mem_limit /= 1024; break; + case 'M': break; + + default: FATAL("Unsupported suffix or bad syntax for -m"); + + } + + if (mem_limit < 5) FATAL("Dangerously low value of -m"); + + if (sizeof(rlim_t) == 4 && mem_limit > 2000) + FATAL("Value of -m out of range on 32-bit systems"); + + } + + break; + + case 't': + + if (timeout_given) FATAL("Multiple -t options not supported"); + timeout_given = 1; + + exec_tmout = atoi(optarg); + + if (exec_tmout < 10 || optarg[0] == '-') + FATAL("Dangerously low value of -t"); + + break; + + case 'Q': + + if (qemu_mode) FATAL("Multiple -Q options not supported"); + if (!mem_limit_given) mem_limit = MEM_LIMIT_QEMU; + + qemu_mode = 1; + break; + + case 'B': /* load bitmap */ + + /* This is a secret undocumented option! It is speculated to be useful + if you have a baseline "boring" input file and another "interesting" + file you want to minimize. + + You can dump a binary bitmap for the boring file using + afl-showmap -b, and then load it into afl-tmin via -B. The minimizer + will then minimize to preserve only the edges that are unique to + the interesting input file, but ignoring everything from the + original map. + + The option may be extended and made more official if it proves + to be useful. */ + + if (mask_bitmap) FATAL("Multiple -B options not supported"); + mask_bitmap = ck_alloc(MAP_SIZE); + read_bitmap(optarg); + break; + + case 'V': /* Show version number */ + + /* Version number has been printed already, just quit. */ + exit(0); + + default: + + usage(argv[0]); + + } + + if (optind == argc || !in_file || !out_file) usage(argv[0]); + + setup_shm(); + setup_signal_handlers(); + + set_up_environment(); + + find_binary(argv[optind]); + detect_file_args(argv + optind); + + if (qemu_mode) + use_argv = get_qemu_argv(argv[0], argv + optind, argc - optind); + else + use_argv = argv + optind; + + exact_mode = !!getenv("AFL_TMIN_EXACT"); + + SAYF("\n"); + + read_initial_file(); + + ACTF("Performing dry run (mem limit = %llu MB, timeout = %u ms%s)...", + mem_limit, exec_tmout, edges_only ? ", edges only" : ""); + + run_target(use_argv, in_data, in_len, 1); + + if (child_timed_out) + FATAL("Target binary times out (adjusting -t may help)."); + + if (!crash_mode) { + + OKF("Program terminates normally, minimizing in " + cCYA "instrumented" cRST " mode."); + + if (!anything_set()) FATAL("No instrumentation detected."); + + } else { + + OKF("Program exits with a signal, minimizing in " cMGN "%scrash" cRST + " mode.", exact_mode ? "EXACT " : ""); + + } + + minimize(use_argv); + + ACTF("Writing output to '%s'...", out_file); + + unlink(prog_in); + prog_in = NULL; + + close(write_to_file(out_file, in_data, in_len)); + + OKF("We're done here. Have a nice day!\n"); + + exit(0); + +} + diff --git a/src/afl-whatsup b/src/afl-whatsup new file mode 100644 index 0000000..bf1f7ca --- /dev/null +++ b/src/afl-whatsup @@ -0,0 +1,163 @@ +#!/bin/sh +# +# american fuzzy lop - status check tool +# -------------------------------------- +# +# Written and maintained by Michal Zalewski +# +# Copyright 2015 Google LLC All rights reserved. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at: +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# This tool summarizes the status of any locally-running synchronized +# instances of afl-fuzz. +# + +echo "status check tool for afl-fuzz by " +echo + +if [ "$1" = "-s" ]; then + + SUMMARY_ONLY=1 + DIR="$2" + +else + + unset SUMMARY_ONLY + DIR="$1" + +fi + +if [ "$DIR" = "" ]; then + + echo "Usage: $0 [ -s ] afl_sync_dir" 1>&2 + echo 1>&2 + echo "The -s option causes the tool to skip all the per-fuzzer trivia and show" 1>&2 + echo "just the summary results. See docs/parallel_fuzzing.txt for additional tips." 1>&2 + echo 1>&2 + exit 1 + +fi + +cd "$DIR" || exit 1 + +if [ -d queue ]; then + + echo "[-] Error: parameter is an individual output directory, not a sync dir." 1>&2 + exit 1 + +fi + +CUR_TIME=`date +%s` + +TMP=`mktemp -t .afl-whatsup-XXXXXXXX` || TMP=`mktemp -p /data/local/tmp .afl-whatsup-XXXXXXXX` || exit 1 + +ALIVE_CNT=0 +DEAD_CNT=0 + +TOTAL_TIME=0 +TOTAL_EXECS=0 +TOTAL_EPS=0 +TOTAL_CRASHES=0 +TOTAL_PFAV=0 +TOTAL_PENDING=0 + +if [ "$SUMMARY_ONLY" = "" ]; then + + echo "Individual fuzzers" + echo "==================" + echo + +fi + +for i in `find . -maxdepth 2 -iname fuzzer_stats | sort`; do + + sed 's/^command_line.*$/_skip:1/;s/[ ]*:[ ]*/="/;s/$/"/' "$i" >"$TMP" + . "$TMP" + + RUN_UNIX=$((CUR_TIME - start_time)) + RUN_DAYS=$((RUN_UNIX / 60 / 60 / 24)) + RUN_HRS=$(((RUN_UNIX / 60 / 60) % 24)) + + if [ "$SUMMARY_ONLY" = "" ]; then + + echo ">>> $afl_banner ($RUN_DAYS days, $RUN_HRS hrs) <<<" + echo + + fi + + if ! kill -0 "$fuzzer_pid" 2>/dev/null; then + + if [ "$SUMMARY_ONLY" = "" ]; then + + echo " Instance is dead or running remotely, skipping." + echo + + fi + + DEAD_CNT=$((DEAD_CNT + 1)) + continue + + fi + + ALIVE_CNT=$((ALIVE_CNT + 1)) + + EXEC_SEC=$((execs_done / RUN_UNIX)) + PATH_PERC=$((cur_path * 100 / paths_total)) + + TOTAL_TIME=$((TOTAL_TIME + RUN_UNIX)) + TOTAL_EPS=$((TOTAL_EPS + EXEC_SEC)) + TOTAL_EXECS=$((TOTAL_EXECS + execs_done)) + TOTAL_CRASHES=$((TOTAL_CRASHES + unique_crashes)) + TOTAL_PENDING=$((TOTAL_PENDING + pending_total)) + TOTAL_PFAV=$((TOTAL_PFAV + pending_favs)) + + if [ "$SUMMARY_ONLY" = "" ]; then + + echo " cycle $((cycles_done + 1)), lifetime speed $EXEC_SEC execs/sec, path $cur_path/$paths_total (${PATH_PERC}%)" + + if [ "$unique_crashes" = "0" ]; then + echo " pending $pending_favs/$pending_total, coverage $bitmap_cvg, no crashes yet" + else + echo " pending $pending_favs/$pending_total, coverage $bitmap_cvg, crash count $unique_crashes (!)" + fi + + echo + + fi + +done + +rm -f "$TMP" + +TOTAL_DAYS=$((TOTAL_TIME / 60 / 60 / 24)) +TOTAL_HRS=$(((TOTAL_TIME / 60 / 60) % 24)) + +test "$TOTAL_TIME" = "0" && TOTAL_TIME=1 + +echo "Summary stats" +echo "=============" +echo +echo " Fuzzers alive : $ALIVE_CNT" + +if [ ! "$DEAD_CNT" = "0" ]; then + echo " Dead or remote : $DEAD_CNT (excluded from stats)" +fi + +echo " Total run time : $TOTAL_DAYS days, $TOTAL_HRS hours" +echo " Total execs : $((TOTAL_EXECS / 1000 / 1000)) million" +echo " Cumulative speed : $TOTAL_EPS execs/sec" +echo " Pending paths : $TOTAL_PFAV faves, $TOTAL_PENDING total" + +if [ "$ALIVE_CNT" -gt "1" ]; then + echo " Pending per fuzzer : $((TOTAL_PFAV/ALIVE_CNT)) faves, $((TOTAL_PENDING/ALIVE_CNT)) total (on average)" +fi + +echo " Crashes found : $TOTAL_CRASHES locally unique" +echo + +exit 0 diff --git a/src/alloc-inl.h b/src/alloc-inl.h new file mode 100644 index 0000000..9a68126 --- /dev/null +++ b/src/alloc-inl.h @@ -0,0 +1,577 @@ +/* + Copyright 2013 Google LLC All rights reserved. + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at: + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +*/ + +/* + american fuzzy lop - error-checking, memory-zeroing alloc routines + ------------------------------------------------------------------ + + Written and maintained by Michal Zalewski + + This allocator is not designed to resist malicious attackers (the canaries + are small and predictable), but provides a robust and portable way to detect + use-after-free, off-by-one writes, stale pointers, and so on. +*/ + +#ifndef _HAVE_ALLOC_INL_H +#define _HAVE_ALLOC_INL_H + +#include +#include +#include + +#include "config.h" +#include "types.h" +#include "debug.h" + +/* User-facing macro to sprintf() to a dynamically allocated buffer. */ + +#define alloc_printf(_str...) ({ \ + u8* _tmp; \ + s32 _len = snprintf(NULL, 0, _str); \ + if (_len < 0) FATAL("Whoa, snprintf() fails?!"); \ + _tmp = ck_alloc(_len + 1); \ + snprintf((char*)_tmp, _len + 1, _str); \ + _tmp; \ + }) + +/* Macro to enforce allocation limits as a last-resort defense against + integer overflows. */ + +#define ALLOC_CHECK_SIZE(_s) do { \ + if ((_s) > MAX_ALLOC) \ + ABORT("Bad alloc request: %u bytes", (_s)); \ + } while (0) + +/* Macro to check malloc() failures and the like. */ + +#define ALLOC_CHECK_RESULT(_r, _s) do { \ + if (!(_r)) \ + ABORT("Out of memory: can't allocate %u bytes", (_s)); \ + } while (0) + +/* Magic tokens used to mark used / freed chunks. */ + +#define ALLOC_MAGIC_C1 0xFF00FF00 /* Used head (dword) */ +#define ALLOC_MAGIC_F 0xFE00FE00 /* Freed head (dword) */ +#define ALLOC_MAGIC_C2 0xF0 /* Used tail (byte) */ + +/* Positions of guard tokens in relation to the user-visible pointer. */ + +#define ALLOC_C1(_ptr) (((u32*)(_ptr))[-2]) +#define ALLOC_S(_ptr) (((u32*)(_ptr))[-1]) +#define ALLOC_C2(_ptr) (((u8*)(_ptr))[ALLOC_S(_ptr)]) + +#define ALLOC_OFF_HEAD 8 +#define ALLOC_OFF_TOTAL (ALLOC_OFF_HEAD + 1) + +/* Allocator increments for ck_realloc_block(). */ + +#define ALLOC_BLK_INC 256 + +/* Sanity-checking macros for pointers. */ + +#define CHECK_PTR(_p) do { \ + if (_p) { \ + if (ALLOC_C1(_p) ^ ALLOC_MAGIC_C1) {\ + if (ALLOC_C1(_p) == ALLOC_MAGIC_F) \ + ABORT("Use after free."); \ + else ABORT("Corrupted head alloc canary."); \ + } \ + if (ALLOC_C2(_p) ^ ALLOC_MAGIC_C2) \ + ABORT("Corrupted tail alloc canary."); \ + } \ + } while (0) + +#define CHECK_PTR_EXPR(_p) ({ \ + typeof (_p) _tmp = (_p); \ + CHECK_PTR(_tmp); \ + _tmp; \ + }) + + +/* Allocate a buffer, explicitly not zeroing it. Returns NULL for zero-sized + requests. */ + +static inline void* DFL_ck_alloc_nozero(u32 size) { + + void* ret; + + if (!size) return NULL; + + ALLOC_CHECK_SIZE(size); + ret = malloc(size + ALLOC_OFF_TOTAL); + ALLOC_CHECK_RESULT(ret, size); + + ret += ALLOC_OFF_HEAD; + + ALLOC_C1(ret) = ALLOC_MAGIC_C1; + ALLOC_S(ret) = size; + ALLOC_C2(ret) = ALLOC_MAGIC_C2; + + return ret; + +} + + +/* Allocate a buffer, returning zeroed memory. */ + +static inline void* DFL_ck_alloc(u32 size) { + + void* mem; + + if (!size) return NULL; + mem = DFL_ck_alloc_nozero(size); + + return memset(mem, 0, size); + +} + + +/* Free memory, checking for double free and corrupted heap. When DEBUG_BUILD + is set, the old memory will be also clobbered with 0xFF. */ + +static inline void DFL_ck_free(void* mem) { + + if (!mem) return; + + CHECK_PTR(mem); + +#ifdef DEBUG_BUILD + + /* Catch pointer issues sooner. */ + memset(mem, 0xFF, ALLOC_S(mem)); + +#endif /* DEBUG_BUILD */ + + ALLOC_C1(mem) = ALLOC_MAGIC_F; + + free(mem - ALLOC_OFF_HEAD); + +} + + +/* Re-allocate a buffer, checking for issues and zeroing any newly-added tail. + With DEBUG_BUILD, the buffer is always reallocated to a new addresses and the + old memory is clobbered with 0xFF. */ + +static inline void* DFL_ck_realloc(void* orig, u32 size) { + + void* ret; + u32 old_size = 0; + + if (!size) { + + DFL_ck_free(orig); + return NULL; + + } + + if (orig) { + + CHECK_PTR(orig); + +#ifndef DEBUG_BUILD + ALLOC_C1(orig) = ALLOC_MAGIC_F; +#endif /* !DEBUG_BUILD */ + + old_size = ALLOC_S(orig); + orig -= ALLOC_OFF_HEAD; + + ALLOC_CHECK_SIZE(old_size); + + } + + ALLOC_CHECK_SIZE(size); + +#ifndef DEBUG_BUILD + + ret = realloc(orig, size + ALLOC_OFF_TOTAL); + ALLOC_CHECK_RESULT(ret, size); + +#else + + /* Catch pointer issues sooner: force relocation and make sure that the + original buffer is wiped. */ + + ret = malloc(size + ALLOC_OFF_TOTAL); + ALLOC_CHECK_RESULT(ret, size); + + if (orig) { + + memcpy(ret + ALLOC_OFF_HEAD, orig + ALLOC_OFF_HEAD, MIN(size, old_size)); + memset(orig + ALLOC_OFF_HEAD, 0xFF, old_size); + + ALLOC_C1(orig + ALLOC_OFF_HEAD) = ALLOC_MAGIC_F; + + free(orig); + + } + +#endif /* ^!DEBUG_BUILD */ + + ret += ALLOC_OFF_HEAD; + + ALLOC_C1(ret) = ALLOC_MAGIC_C1; + ALLOC_S(ret) = size; + ALLOC_C2(ret) = ALLOC_MAGIC_C2; + + if (size > old_size) + memset(ret + old_size, 0, size - old_size); + + return ret; + +} + + +/* Re-allocate a buffer with ALLOC_BLK_INC increments (used to speed up + repeated small reallocs without complicating the user code). */ + +static inline void* DFL_ck_realloc_block(void* orig, u32 size) { + +#ifndef DEBUG_BUILD + + if (orig) { + + CHECK_PTR(orig); + + if (ALLOC_S(orig) >= size) return orig; + + size += ALLOC_BLK_INC; + + } + +#endif /* !DEBUG_BUILD */ + + return DFL_ck_realloc(orig, size); + +} + + +/* Create a buffer with a copy of a string. Returns NULL for NULL inputs. */ + +static inline u8* DFL_ck_strdup(u8* str) { + + void* ret; + u32 size; + + if (!str) return NULL; + + size = strlen((char*)str) + 1; + + ALLOC_CHECK_SIZE(size); + ret = malloc(size + ALLOC_OFF_TOTAL); + ALLOC_CHECK_RESULT(ret, size); + + ret += ALLOC_OFF_HEAD; + + ALLOC_C1(ret) = ALLOC_MAGIC_C1; + ALLOC_S(ret) = size; + ALLOC_C2(ret) = ALLOC_MAGIC_C2; + + return memcpy(ret, str, size); + +} + + +/* Create a buffer with a copy of a memory block. Returns NULL for zero-sized + or NULL inputs. */ + +static inline void* DFL_ck_memdup(void* mem, u32 size) { + + void* ret; + + if (!mem || !size) return NULL; + + ALLOC_CHECK_SIZE(size); + ret = malloc(size + ALLOC_OFF_TOTAL); + ALLOC_CHECK_RESULT(ret, size); + + ret += ALLOC_OFF_HEAD; + + ALLOC_C1(ret) = ALLOC_MAGIC_C1; + ALLOC_S(ret) = size; + ALLOC_C2(ret) = ALLOC_MAGIC_C2; + + return memcpy(ret, mem, size); + +} + + +/* Create a buffer with a block of text, appending a NUL terminator at the end. + Returns NULL for zero-sized or NULL inputs. */ + +static inline u8* DFL_ck_memdup_str(u8* mem, u32 size) { + + u8* ret; + + if (!mem || !size) return NULL; + + ALLOC_CHECK_SIZE(size); + ret = malloc(size + ALLOC_OFF_TOTAL + 1); + ALLOC_CHECK_RESULT(ret, size); + + ret += ALLOC_OFF_HEAD; + + ALLOC_C1(ret) = ALLOC_MAGIC_C1; + ALLOC_S(ret) = size; + ALLOC_C2(ret) = ALLOC_MAGIC_C2; + + memcpy(ret, mem, size); + ret[size] = 0; + + return ret; + +} + + +#ifndef DEBUG_BUILD + +/* In non-debug mode, we just do straightforward aliasing of the above functions + to user-visible names such as ck_alloc(). */ + +#define ck_alloc DFL_ck_alloc +#define ck_alloc_nozero DFL_ck_alloc_nozero +#define ck_realloc DFL_ck_realloc +#define ck_realloc_block DFL_ck_realloc_block +#define ck_strdup DFL_ck_strdup +#define ck_memdup DFL_ck_memdup +#define ck_memdup_str DFL_ck_memdup_str +#define ck_free DFL_ck_free + +#define alloc_report() + +#else + +/* In debugging mode, we also track allocations to detect memory leaks, and the + flow goes through one more layer of indirection. */ + +/* Alloc tracking data structures: */ + +#define ALLOC_BUCKETS 4096 + +struct TRK_obj { + void *ptr; + char *file, *func; + u32 line; +}; + +#ifdef AFL_MAIN + +struct TRK_obj* TRK[ALLOC_BUCKETS]; +u32 TRK_cnt[ALLOC_BUCKETS]; + +# define alloc_report() TRK_report() + +#else + +extern struct TRK_obj* TRK[ALLOC_BUCKETS]; +extern u32 TRK_cnt[ALLOC_BUCKETS]; + +# define alloc_report() + +#endif /* ^AFL_MAIN */ + +/* Bucket-assigning function for a given pointer: */ + +#define TRKH(_ptr) (((((u32)(_ptr)) >> 16) ^ ((u32)(_ptr))) % ALLOC_BUCKETS) + + +/* Add a new entry to the list of allocated objects. */ + +static inline void TRK_alloc_buf(void* ptr, const char* file, const char* func, + u32 line) { + + u32 i, bucket; + + if (!ptr) return; + + bucket = TRKH(ptr); + + /* Find a free slot in the list of entries for that bucket. */ + + for (i = 0; i < TRK_cnt[bucket]; i++) + + if (!TRK[bucket][i].ptr) { + + TRK[bucket][i].ptr = ptr; + TRK[bucket][i].file = (char*)file; + TRK[bucket][i].func = (char*)func; + TRK[bucket][i].line = line; + return; + + } + + /* No space available - allocate more. */ + + TRK[bucket] = DFL_ck_realloc_block(TRK[bucket], + (TRK_cnt[bucket] + 1) * sizeof(struct TRK_obj)); + + TRK[bucket][i].ptr = ptr; + TRK[bucket][i].file = (char*)file; + TRK[bucket][i].func = (char*)func; + TRK[bucket][i].line = line; + + TRK_cnt[bucket]++; + +} + + +/* Remove entry from the list of allocated objects. */ + +static inline void TRK_free_buf(void* ptr, const char* file, const char* func, + u32 line) { + + u32 i, bucket; + + if (!ptr) return; + + bucket = TRKH(ptr); + + /* Find the element on the list... */ + + for (i = 0; i < TRK_cnt[bucket]; i++) + + if (TRK[bucket][i].ptr == ptr) { + + TRK[bucket][i].ptr = 0; + return; + + } + + WARNF("ALLOC: Attempt to free non-allocated memory in %s (%s:%u)", + func, file, line); + +} + + +/* Do a final report on all non-deallocated objects. */ + +static inline void TRK_report(void) { + + u32 i, bucket; + + fflush(0); + + for (bucket = 0; bucket < ALLOC_BUCKETS; bucket++) + for (i = 0; i < TRK_cnt[bucket]; i++) + if (TRK[bucket][i].ptr) + WARNF("ALLOC: Memory never freed, created in %s (%s:%u)", + TRK[bucket][i].func, TRK[bucket][i].file, TRK[bucket][i].line); + +} + + +/* Simple wrappers for non-debugging functions: */ + +static inline void* TRK_ck_alloc(u32 size, const char* file, const char* func, + u32 line) { + + void* ret = DFL_ck_alloc(size); + TRK_alloc_buf(ret, file, func, line); + return ret; + +} + + +static inline void* TRK_ck_realloc(void* orig, u32 size, const char* file, + const char* func, u32 line) { + + void* ret = DFL_ck_realloc(orig, size); + TRK_free_buf(orig, file, func, line); + TRK_alloc_buf(ret, file, func, line); + return ret; + +} + + +static inline void* TRK_ck_realloc_block(void* orig, u32 size, const char* file, + const char* func, u32 line) { + + void* ret = DFL_ck_realloc_block(orig, size); + TRK_free_buf(orig, file, func, line); + TRK_alloc_buf(ret, file, func, line); + return ret; + +} + + +static inline void* TRK_ck_strdup(u8* str, const char* file, const char* func, + u32 line) { + + void* ret = DFL_ck_strdup(str); + TRK_alloc_buf(ret, file, func, line); + return ret; + +} + + +static inline void* TRK_ck_memdup(void* mem, u32 size, const char* file, + const char* func, u32 line) { + + void* ret = DFL_ck_memdup(mem, size); + TRK_alloc_buf(ret, file, func, line); + return ret; + +} + + +static inline void* TRK_ck_memdup_str(void* mem, u32 size, const char* file, + const char* func, u32 line) { + + void* ret = DFL_ck_memdup_str(mem, size); + TRK_alloc_buf(ret, file, func, line); + return ret; + +} + + +static inline void TRK_ck_free(void* ptr, const char* file, + const char* func, u32 line) { + + TRK_free_buf(ptr, file, func, line); + DFL_ck_free(ptr); + +} + +/* Aliasing user-facing names to tracking functions: */ + +#define ck_alloc(_p1) \ + TRK_ck_alloc(_p1, __FILE__, __FUNCTION__, __LINE__) + +#define ck_alloc_nozero(_p1) \ + TRK_ck_alloc(_p1, __FILE__, __FUNCTION__, __LINE__) + +#define ck_realloc(_p1, _p2) \ + TRK_ck_realloc(_p1, _p2, __FILE__, __FUNCTION__, __LINE__) + +#define ck_realloc_block(_p1, _p2) \ + TRK_ck_realloc_block(_p1, _p2, __FILE__, __FUNCTION__, __LINE__) + +#define ck_strdup(_p1) \ + TRK_ck_strdup(_p1, __FILE__, __FUNCTION__, __LINE__) + +#define ck_memdup(_p1, _p2) \ + TRK_ck_memdup(_p1, _p2, __FILE__, __FUNCTION__, __LINE__) + +#define ck_memdup_str(_p1, _p2) \ + TRK_ck_memdup_str(_p1, _p2, __FILE__, __FUNCTION__, __LINE__) + +#define ck_free(_p1) \ + TRK_ck_free(_p1, __FILE__, __FUNCTION__, __LINE__) + +#endif /* ^!DEBUG_BUILD */ + +#endif /* ! _HAVE_ALLOC_INL_H */ diff --git a/src/android-ashmem.h b/src/android-ashmem.h new file mode 100644 index 0000000..4922904 --- /dev/null +++ b/src/android-ashmem.h @@ -0,0 +1,82 @@ +#ifdef __ANDROID__ +#ifndef _ANDROID_ASHMEM_H +#define _ANDROID_ASHMEM_H + +#include +#include +#include +#include +#include + +#if __ANDROID_API__ >= 26 +#define shmat bionic_shmat +#define shmctl bionic_shmctl +#define shmdt bionic_shmdt +#define shmget bionic_shmget +#endif +#include +#undef shmat +#undef shmctl +#undef shmdt +#undef shmget +#include + +#define ASHMEM_DEVICE "/dev/ashmem" + +static inline int shmctl(int __shmid, int __cmd, struct shmid_ds *__buf) { + int ret = 0; + if (__cmd == IPC_RMID) { + int length = ioctl(__shmid, ASHMEM_GET_SIZE, NULL); + struct ashmem_pin pin = {0, length}; + ret = ioctl(__shmid, ASHMEM_UNPIN, &pin); + close(__shmid); + } + + return ret; +} + +static inline int shmget(key_t __key, size_t __size, int __shmflg) { + (void) __shmflg; + int fd, ret; + char ourkey[11]; + + fd = open(ASHMEM_DEVICE, O_RDWR); + if (fd < 0) + return fd; + + sprintf(ourkey, "%d", __key); + ret = ioctl(fd, ASHMEM_SET_NAME, ourkey); + if (ret < 0) + goto error; + + ret = ioctl(fd, ASHMEM_SET_SIZE, __size); + if (ret < 0) + goto error; + + return fd; + +error: + close(fd); + return ret; +} + +static inline void *shmat(int __shmid, const void *__shmaddr, int __shmflg) { + (void) __shmflg; + int size; + void *ptr; + + size = ioctl(__shmid, ASHMEM_GET_SIZE, NULL); + if (size < 0) { + return NULL; + } + + ptr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, __shmid, 0); + if (ptr == MAP_FAILED) { + return NULL; + } + + return ptr; +} + +#endif /* !_ANDROID_ASHMEM_H */ +#endif /* !__ANDROID__ */ diff --git a/src/config.h b/src/config.h new file mode 100644 index 0000000..46dd857 --- /dev/null +++ b/src/config.h @@ -0,0 +1,362 @@ +/* + Copyright 2013 Google LLC All rights reserved. + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at: + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +*/ + +/* + american fuzzy lop - vaguely configurable bits + ---------------------------------------------- + + Written and maintained by Michal Zalewski +*/ + +#ifndef _HAVE_CONFIG_H +#define _HAVE_CONFIG_H + +#include "types.h" + +/* Version string: */ + +#define VERSION "2.57b" + +/****************************************************** + * * + * Settings that may be of interest to power users: * + * * + ******************************************************/ + +/* Comment out to disable terminal colors (note that this makes afl-analyze + a lot less nice): */ + +#define USE_COLOR + +/* Comment out to disable fancy ANSI boxes and use poor man's 7-bit UI: */ + +#define FANCY_BOXES + +/* Default timeout for fuzzed code (milliseconds). This is the upper bound, + also used for detecting hangs; the actual value is auto-scaled: */ + +#define EXEC_TIMEOUT 1000 + +/* Timeout rounding factor when auto-scaling (milliseconds): */ + +#define EXEC_TM_ROUND 20 + +/* 64bit arch MACRO */ +#if (defined (__x86_64__) || defined (__arm64__) || defined (__aarch64__)) +#define WORD_SIZE_64 1 +#endif + +/* Default memory limit for child process (MB): */ + +#ifndef WORD_SIZE_64 +# define MEM_LIMIT 25 +#else +# define MEM_LIMIT 50 +#endif /* ^!WORD_SIZE_64 */ + +/* Default memory limit when running in QEMU mode (MB): */ + +#define MEM_LIMIT_QEMU 200 + +/* Number of calibration cycles per every new test case (and for test + cases that show variable behavior): */ + +#define CAL_CYCLES 8 +#define CAL_CYCLES_LONG 40 + +/* Number of subsequent timeouts before abandoning an input file: */ + +#define TMOUT_LIMIT 250 + +/* Maximum number of unique hangs or crashes to record: */ + +#define KEEP_UNIQUE_HANG 500 +#define KEEP_UNIQUE_CRASH 5000 + +/* Baseline number of random tweaks during a single 'havoc' stage: */ + +#define HAVOC_CYCLES 256 +#define HAVOC_CYCLES_INIT 1024 + +/* Maximum multiplier for the above (should be a power of two, beware + of 32-bit int overflows): */ + +#define HAVOC_MAX_MULT 16 + +/* Absolute minimum number of havoc cycles (after all adjustments): */ + +#define HAVOC_MIN 16 + +/* Maximum stacking for havoc-stage tweaks. The actual value is calculated + like this: + + n = random between 1 and HAVOC_STACK_POW2 + stacking = 2^n + + In other words, the default (n = 7) produces 2, 4, 8, 16, 32, 64, or + 128 stacked tweaks: */ + +#define HAVOC_STACK_POW2 7 + +/* Caps on block sizes for cloning and deletion operations. Each of these + ranges has a 33% probability of getting picked, except for the first + two cycles where smaller blocks are favored: */ + +#define HAVOC_BLK_SMALL 32 +#define HAVOC_BLK_MEDIUM 128 +#define HAVOC_BLK_LARGE 1500 + +/* Extra-large blocks, selected very rarely (<5% of the time): */ + +#define HAVOC_BLK_XL 32768 + +/* Probabilities of skipping non-favored entries in the queue, expressed as + percentages: */ + +#define SKIP_TO_NEW_PROB 99 /* ...when there are new, pending favorites */ +#define SKIP_NFAV_OLD_PROB 95 /* ...no new favs, cur entry already fuzzed */ +#define SKIP_NFAV_NEW_PROB 75 /* ...no new favs, cur entry not fuzzed yet */ + +/* Splicing cycle count: */ + +#define SPLICE_CYCLES 15 + +/* Nominal per-splice havoc cycle length: */ + +#define SPLICE_HAVOC 32 + +/* Maximum offset for integer addition / subtraction stages: */ + +#define ARITH_MAX 35 + +/* Limits for the test case trimmer. The absolute minimum chunk size; and + the starting and ending divisors for chopping up the input file: */ + +#define TRIM_MIN_BYTES 4 +#define TRIM_START_STEPS 16 +#define TRIM_END_STEPS 1024 + +/* Maximum size of input file, in bytes (keep under 100MB): */ + +#define MAX_FILE (1 * 1024 * 1024) + +/* The same, for the test case minimizer: */ + +#define TMIN_MAX_FILE (10 * 1024 * 1024) + +/* Block normalization steps for afl-tmin: */ + +#define TMIN_SET_MIN_SIZE 4 +#define TMIN_SET_STEPS 128 + +/* Maximum dictionary token size (-x), in bytes: */ + +#define MAX_DICT_FILE 128 + +/* Length limits for auto-detected dictionary tokens: */ + +#define MIN_AUTO_EXTRA 3 +#define MAX_AUTO_EXTRA 32 + +/* Maximum number of user-specified dictionary tokens to use in deterministic + steps; past this point, the "extras/user" step will be still carried out, + but with proportionally lower odds: */ + +#define MAX_DET_EXTRAS 200 + +/* Maximum number of auto-extracted dictionary tokens to actually use in fuzzing + (first value), and to keep in memory as candidates. The latter should be much + higher than the former. */ + +#define USE_AUTO_EXTRAS 50 +#define MAX_AUTO_EXTRAS (USE_AUTO_EXTRAS * 10) + +/* Scaling factor for the effector map used to skip some of the more + expensive deterministic steps. The actual divisor is set to + 2^EFF_MAP_SCALE2 bytes: */ + +#define EFF_MAP_SCALE2 3 + +/* Minimum input file length at which the effector logic kicks in: */ + +#define EFF_MIN_LEN 128 + +/* Maximum effector density past which everything is just fuzzed + unconditionally (%): */ + +#define EFF_MAX_PERC 90 + +/* UI refresh frequency (Hz): */ + +#define UI_TARGET_HZ 5 + +/* Fuzzer stats file and plot update intervals (sec): */ + +#define STATS_UPDATE_SEC 60 +#define PLOT_UPDATE_SEC 5 + +/* Smoothing divisor for CPU load and exec speed stats (1 - no smoothing). */ + +#define AVG_SMOOTHING 16 + +/* Sync interval (every n havoc cycles): */ + +#define SYNC_INTERVAL 5 + +/* Output directory reuse grace period (minutes): */ + +#define OUTPUT_GRACE 25 + +/* Uncomment to use simple file names (id_NNNNNN): */ + +// #define SIMPLE_FILES + +/* List of interesting values to use in fuzzing. */ + +#define INTERESTING_8 \ + -128, /* Overflow signed 8-bit when decremented */ \ + -1, /* */ \ + 0, /* */ \ + 1, /* */ \ + 16, /* One-off with common buffer size */ \ + 32, /* One-off with common buffer size */ \ + 64, /* One-off with common buffer size */ \ + 100, /* One-off with common buffer size */ \ + 127 /* Overflow signed 8-bit when incremented */ + +#define INTERESTING_16 \ + -32768, /* Overflow signed 16-bit when decremented */ \ + -129, /* Overflow signed 8-bit */ \ + 128, /* Overflow signed 8-bit */ \ + 255, /* Overflow unsig 8-bit when incremented */ \ + 256, /* Overflow unsig 8-bit */ \ + 512, /* One-off with common buffer size */ \ + 1000, /* One-off with common buffer size */ \ + 1024, /* One-off with common buffer size */ \ + 4096, /* One-off with common buffer size */ \ + 32767 /* Overflow signed 16-bit when incremented */ + +#define INTERESTING_32 \ + -2147483648LL, /* Overflow signed 32-bit when decremented */ \ + -100663046, /* Large negative number (endian-agnostic) */ \ + -32769, /* Overflow signed 16-bit */ \ + 32768, /* Overflow signed 16-bit */ \ + 65535, /* Overflow unsig 16-bit when incremented */ \ + 65536, /* Overflow unsig 16 bit */ \ + 100663045, /* Large positive number (endian-agnostic) */ \ + 2147483647 /* Overflow signed 32-bit when incremented */ + +/*********************************************************** + * * + * Really exotic stuff you probably don't want to touch: * + * * + ***********************************************************/ + +/* Call count interval between reseeding the libc PRNG from /dev/urandom: */ + +#define RESEED_RNG 10000 + +/* Maximum line length passed from GCC to 'as' and used for parsing + configuration files: */ + +#define MAX_LINE 8192 + +/* Environment variable used to pass SHM ID to the called program. */ + +#define SHM_ENV_VAR "__AFL_SHM_ID" + +/* Other less interesting, internal-only variables. */ + +#define CLANG_ENV_VAR "__AFL_CLANG_MODE" +#define AS_LOOP_ENV_VAR "__AFL_AS_LOOPCHECK" +#define PERSIST_ENV_VAR "__AFL_PERSISTENT" +#define DEFER_ENV_VAR "__AFL_DEFER_FORKSRV" + +/* In-code signatures for deferred and persistent mode. */ + +#define PERSIST_SIG "##SIG_AFL_PERSISTENT##" +#define DEFER_SIG "##SIG_AFL_DEFER_FORKSRV##" + +/* Distinctive bitmap signature used to indicate failed execution: */ + +#define EXEC_FAIL_SIG 0xfee1dead + +/* Distinctive exit code used to indicate MSAN trip condition: */ + +#define MSAN_ERROR 86 + +/* Designated file descriptors for forkserver commands (the application will + use FORKSRV_FD and FORKSRV_FD + 1): */ + +#define FORKSRV_FD 198 + +/* Fork server init timeout multiplier: we'll wait the user-selected + timeout plus this much for the fork server to spin up. */ + +#define FORK_WAIT_MULT 10 + +/* Calibration timeout adjustments, to be a bit more generous when resuming + fuzzing sessions or trying to calibrate already-added internal finds. + The first value is a percentage, the other is in milliseconds: */ + +#define CAL_TMOUT_PERC 125 +#define CAL_TMOUT_ADD 50 + +/* Number of chances to calibrate a case before giving up: */ + +#define CAL_CHANCES 3 + +/* Map size for the traced binary (2^MAP_SIZE_POW2). Must be greater than + 2; you probably want to keep it under 18 or so for performance reasons + (adjusting AFL_INST_RATIO when compiling is probably a better way to solve + problems with complex programs). You need to recompile the target binary + after changing this - otherwise, SEGVs may ensue. */ + +#define MAP_SIZE_POW2 16 +#define MAP_SIZE (1 << MAP_SIZE_POW2) + +/* Maximum allocator request size (keep well under INT_MAX): */ + +#define MAX_ALLOC 0x40000000 + +/* A made-up hashing seed: */ + +#define HASH_CONST 0xa5b35705 + +/* Constants for afl-gotcpu to control busy loop timing: */ + +#define CTEST_TARGET_MS 5000 +#define CTEST_CORE_TRG_MS 1000 +#define CTEST_BUSY_CYCLES (10 * 1000 * 1000) + +/* Uncomment this to use inferior block-coverage-based instrumentation. Note + that you need to recompile the target binary for this to have any effect: */ + +// #define COVERAGE_ONLY + +/* Uncomment this to ignore hit counts and output just one bit per tuple. + As with the previous setting, you will need to recompile the target + binary: */ + +// #define SKIP_COUNTS + +/* Uncomment this to use instrumentation data to record newly discovered paths, + but do not use them as seeds for fuzzing. This is useful for conveniently + measuring coverage that could be attained by a "dumb" fuzzing algorithm: */ + +// #define IGNORE_FINDS + +#endif /* ! _HAVE_CONFIG_H */ diff --git a/src/debug.h b/src/debug.h new file mode 100644 index 0000000..5f75974 --- /dev/null +++ b/src/debug.h @@ -0,0 +1,258 @@ +/* + Copyright 2013 Google LLC All rights reserved. + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at: + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +*/ + +/* + american fuzzy lop - debug / error handling macros + -------------------------------------------------- + + Written and maintained by Michal Zalewski +*/ + +#ifndef _HAVE_DEBUG_H +#define _HAVE_DEBUG_H + +#include + +#include "types.h" +#include "config.h" + +/******************* + * Terminal colors * + *******************/ + +#ifdef USE_COLOR + +# define cBLK "\x1b[0;30m" +# define cRED "\x1b[0;31m" +# define cGRN "\x1b[0;32m" +# define cBRN "\x1b[0;33m" +# define cBLU "\x1b[0;34m" +# define cMGN "\x1b[0;35m" +# define cCYA "\x1b[0;36m" +# define cLGR "\x1b[0;37m" +# define cGRA "\x1b[1;90m" +# define cLRD "\x1b[1;91m" +# define cLGN "\x1b[1;92m" +# define cYEL "\x1b[1;93m" +# define cLBL "\x1b[1;94m" +# define cPIN "\x1b[1;95m" +# define cLCY "\x1b[1;96m" +# define cBRI "\x1b[1;97m" +# define cRST "\x1b[0m" + +# define bgBLK "\x1b[40m" +# define bgRED "\x1b[41m" +# define bgGRN "\x1b[42m" +# define bgBRN "\x1b[43m" +# define bgBLU "\x1b[44m" +# define bgMGN "\x1b[45m" +# define bgCYA "\x1b[46m" +# define bgLGR "\x1b[47m" +# define bgGRA "\x1b[100m" +# define bgLRD "\x1b[101m" +# define bgLGN "\x1b[102m" +# define bgYEL "\x1b[103m" +# define bgLBL "\x1b[104m" +# define bgPIN "\x1b[105m" +# define bgLCY "\x1b[106m" +# define bgBRI "\x1b[107m" + +#else + +# define cBLK "" +# define cRED "" +# define cGRN "" +# define cBRN "" +# define cBLU "" +# define cMGN "" +# define cCYA "" +# define cLGR "" +# define cGRA "" +# define cLRD "" +# define cLGN "" +# define cYEL "" +# define cLBL "" +# define cPIN "" +# define cLCY "" +# define cBRI "" +# define cRST "" + +# define bgBLK "" +# define bgRED "" +# define bgGRN "" +# define bgBRN "" +# define bgBLU "" +# define bgMGN "" +# define bgCYA "" +# define bgLGR "" +# define bgGRA "" +# define bgLRD "" +# define bgLGN "" +# define bgYEL "" +# define bgLBL "" +# define bgPIN "" +# define bgLCY "" +# define bgBRI "" + +#endif /* ^USE_COLOR */ + +/************************* + * Box drawing sequences * + *************************/ + +#ifdef FANCY_BOXES + +# define SET_G1 "\x1b)0" /* Set G1 for box drawing */ +# define RESET_G1 "\x1b)B" /* Reset G1 to ASCII */ +# define bSTART "\x0e" /* Enter G1 drawing mode */ +# define bSTOP "\x0f" /* Leave G1 drawing mode */ +# define bH "q" /* Horizontal line */ +# define bV "x" /* Vertical line */ +# define bLT "l" /* Left top corner */ +# define bRT "k" /* Right top corner */ +# define bLB "m" /* Left bottom corner */ +# define bRB "j" /* Right bottom corner */ +# define bX "n" /* Cross */ +# define bVR "t" /* Vertical, branch right */ +# define bVL "u" /* Vertical, branch left */ +# define bHT "v" /* Horizontal, branch top */ +# define bHB "w" /* Horizontal, branch bottom */ + +#else + +# define SET_G1 "" +# define RESET_G1 "" +# define bSTART "" +# define bSTOP "" +# define bH "-" +# define bV "|" +# define bLT "+" +# define bRT "+" +# define bLB "+" +# define bRB "+" +# define bX "+" +# define bVR "+" +# define bVL "+" +# define bHT "+" +# define bHB "+" + +#endif /* ^FANCY_BOXES */ + +/*********************** + * Misc terminal codes * + ***********************/ + +#define TERM_HOME "\x1b[H" +#define TERM_CLEAR TERM_HOME "\x1b[2J" +#define cEOL "\x1b[0K" +#define CURSOR_HIDE "\x1b[?25l" +#define CURSOR_SHOW "\x1b[?25h" + +/************************ + * Debug & error macros * + ************************/ + +/* Just print stuff to the appropriate stream. */ + +#ifdef MESSAGES_TO_STDOUT +# define SAYF(x...) printf(x) +#else +# define SAYF(x...) fprintf(stderr, x) +#endif /* ^MESSAGES_TO_STDOUT */ + +/* Show a prefixed warning. */ + +#define WARNF(x...) do { \ + SAYF(cYEL "[!] " cBRI "WARNING: " cRST x); \ + SAYF(cRST "\n"); \ + } while (0) + +/* Show a prefixed "doing something" message. */ + +#define ACTF(x...) do { \ + SAYF(cLBL "[*] " cRST x); \ + SAYF(cRST "\n"); \ + } while (0) + +/* Show a prefixed "success" message. */ + +#define OKF(x...) do { \ + SAYF(cLGN "[+] " cRST x); \ + SAYF(cRST "\n"); \ + } while (0) + +/* Show a prefixed fatal error message (not used in afl). */ + +#define BADF(x...) do { \ + SAYF(cLRD "\n[-] " cRST x); \ + SAYF(cRST "\n"); \ + } while (0) + +/* Die with a verbose non-OS fatal error message. */ + +#define FATAL(x...) do { \ + SAYF(bSTOP RESET_G1 CURSOR_SHOW cRST cLRD "\n[-] PROGRAM ABORT : " \ + cBRI x); \ + SAYF(cLRD "\n Location : " cRST "%s(), %s:%u\n\n", \ + __FUNCTION__, __FILE__, __LINE__); \ + exit(1); \ + } while (0) + +/* Die by calling abort() to provide a core dump. */ + +#define ABORT(x...) do { \ + SAYF(bSTOP RESET_G1 CURSOR_SHOW cRST cLRD "\n[-] PROGRAM ABORT : " \ + cBRI x); \ + SAYF(cLRD "\n Stop location : " cRST "%s(), %s:%u\n\n", \ + __FUNCTION__, __FILE__, __LINE__); \ + abort(); \ + } while (0) + +/* Die while also including the output of perror(). */ + +#define PFATAL(x...) do { \ + fflush(stdout); \ + SAYF(bSTOP RESET_G1 CURSOR_SHOW cRST cLRD "\n[-] SYSTEM ERROR : " \ + cBRI x); \ + SAYF(cLRD "\n Stop location : " cRST "%s(), %s:%u\n", \ + __FUNCTION__, __FILE__, __LINE__); \ + SAYF(cLRD " OS message : " cRST "%s\n", strerror(errno)); \ + exit(1); \ + } while (0) + +/* Die with FAULT() or PFAULT() depending on the value of res (used to + interpret different failure modes for read(), write(), etc). */ + +#define RPFATAL(res, x...) do { \ + if (res < 0) PFATAL(x); else FATAL(x); \ + } while (0) + +/* Error-checking versions of read() and write() that call RPFATAL() as + appropriate. */ + +#define ck_write(fd, buf, len, fn) do { \ + u32 _len = (len); \ + s32 _res = write(fd, buf, _len); \ + if (_res != _len) RPFATAL(_res, "Short write to %s", fn); \ + } while (0) + +#define ck_read(fd, buf, len, fn) do { \ + u32 _len = (len); \ + s32 _res = read(fd, buf, _len); \ + if (_res != _len) RPFATAL(_res, "Short read from %s", fn); \ + } while (0) + +#endif /* ! _HAVE_DEBUG_H */ diff --git a/src/dictionaries/README.dictionaries b/src/dictionaries/README.dictionaries new file mode 100644 index 0000000..ea31973 --- /dev/null +++ b/src/dictionaries/README.dictionaries @@ -0,0 +1,43 @@ +================ +AFL dictionaries +================ + + (See ../docs/README for the general instruction manual.) + +This subdirectory contains a set of dictionaries that can be used in +conjunction with the -x option to allow the fuzzer to effortlessly explore the +grammar of some of the more verbose data formats or languages. The basic +principle behind the operation of fuzzer dictionaries is outlined in section 9 +of the "main" README for the project. + +Custom dictionaries can be added at will. They should consist of a +reasonably-sized set of rudimentary syntax units that the fuzzer will then try +to clobber together in various ways. Snippets between 2 and 16 bytes are usually +the sweet spot. + +Custom dictionaries can be created in two ways: + + - By creating a new directory and placing each token in a separate file, in + which case, there is no need to escape or otherwise format the data. + + - By creating a flat text file where tokens are listed one per line in the + format of name="value". The alphanumeric name is ignored and can be omitted, + although it is a convenient way to document the meaning of a particular + token. The value must appear in quotes, with hex escaping (\xNN) applied to + all non-printable, high-bit, or otherwise problematic characters (\\ and \" + shorthands are recognized, too). + +The fuzzer auto-selects the appropriate mode depending on whether the -x +parameter is a file or a directory. + +In the file mode, every name field can be optionally followed by @, e.g.: + + keyword_foo@1 = "foo" + +Such entries will be loaded only if the requested dictionary level is equal or +higher than this number. The default level is zero; a higher value can be set +by appending @ to the dictionary file name, like so: + + -x path/to/dictionary.dct@2 + +Good examples of dictionaries can be found in xml.dict and png.dict. diff --git a/src/dictionaries/gif.dict b/src/dictionaries/gif.dict new file mode 100644 index 0000000..7114893 --- /dev/null +++ b/src/dictionaries/gif.dict @@ -0,0 +1,18 @@ +# +# AFL dictionary for GIF images +# ----------------------------- +# +# Created by Michal Zalewski +# + +header_87a="87a" +header_89a="89a" +header_gif="GIF" + +marker_2c="," +marker_3b=";" + +section_2101="!\x01\x12" +section_21f9="!\xf9\x04" +section_21fe="!\xfe" +section_21ff="!\xff\x11" diff --git a/src/dictionaries/html_tags.dict b/src/dictionaries/html_tags.dict new file mode 100644 index 0000000..ba946df --- /dev/null +++ b/src/dictionaries/html_tags.dict @@ -0,0 +1,160 @@ +# +# AFL dictionary for HTML parsers (tags only) +# ------------------------------------------- +# +# A basic collection of HTML tags likely to matter to HTML parsers. Does *not* +# include any attributes or attribute values. +# +# Created by Michal Zalewski +# + +tag_a="" +tag_abbr="" +tag_acronym="" +tag_address="

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