You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
65 lines
1.9 KiB
65 lines
1.9 KiB
/*
|
|
* Copyright (c) Facebook, Inc. and its affiliates.
|
|
*
|
|
* This source code is licensed under the MIT license found in the
|
|
* LICENSE file in the root directory of this source tree.
|
|
*/
|
|
|
|
#include <cstdint>
|
|
#include <memory>
|
|
#include <stdexcept>
|
|
|
|
extern int __infer_taint_source();
|
|
|
|
namespace std {
|
|
template <class T>
|
|
unique_ptr<T> make_unique(size_t n) {
|
|
typedef typename remove_extent<T>::type U;
|
|
return unique_ptr<T>(new U[n]());
|
|
}
|
|
} // namespace std
|
|
|
|
namespace Codec_Bad {
|
|
uint32_t getP_Bad(uint32_t w) {
|
|
auto w4 = w * 4; // BUG: can overflow
|
|
auto w4m1 = w4 - 1; // BUG: can underflow (if w = 0)
|
|
auto w4m1o15 = w4m1 | 15; // ALWAYS OK
|
|
auto w4m1o15p1 = w4m1o15 + 1; // BUG: can overflow
|
|
return w4m1o15p1;
|
|
}
|
|
void foo_Bad_FN() {
|
|
int w = __infer_taint_source();
|
|
int h = __infer_taint_source();
|
|
auto p =
|
|
getP_Bad(w); // MISSED BUG: downcasting signed int64 -> unsigned int32
|
|
auto s = h * p; // BUG: multiplication can overflow
|
|
auto d = std::make_unique<uint8_t[]>(s); // MISSED BUG: casting signed int64
|
|
// -> unsigned int64,
|
|
}
|
|
} // namespace Codec_Bad
|
|
|
|
namespace Codec_Bad2 {
|
|
uint64_t getP_Bad(uint64_t w) {
|
|
auto w4 = w * 4; // BUG: can overflow
|
|
auto w4m1 = w4 - 1; // BUG: can underflow (if w = 0)
|
|
auto w4m1o15 = w4m1 | 15; // ALWAYS OK
|
|
auto w4m1o15p1 = w4m1o15 + 1; // BUG: can overflow
|
|
return w4m1o15p1;
|
|
}
|
|
uint64_t checkedMultiply_Good(uint64_t a, uint64_t b) {
|
|
__uint128_t mul = ((__uint128_t)a) * b; // OK: no overflow
|
|
if ((mul >> 64) != 0) {
|
|
throw std::runtime_error("Detected overflow in checked multiplcation");
|
|
}
|
|
auto result = (uint64_t)mul; // OK: within the bounds
|
|
return result;
|
|
}
|
|
void foo_Bad_FN_FP() {
|
|
int w = __infer_taint_source();
|
|
int h = __infer_taint_source();
|
|
auto p = getP_Bad(w); // MISSED BUG: casting signed int64 -> unsigned int64
|
|
auto s = checkedMultiply_Good(h, p); // OK, FP
|
|
auto d = std::make_unique<uint8_t[]>(s); // OK
|
|
}
|
|
} // namespace Codec_Bad2
|