[quandary] use sink index info when expanding traces

Reviewed By: jvillard

Differential Revision: D5190988

fbshipit-source-id: f0dc17b

infer/src/checkers/Trace.ml

@@ -76,6 +76,8 @@ module type S = sig
 
   val update_sinks : t -> Sinks.t -> t
 
+  val get_footprint_indexes : t -> IntSet.t
+
   (** append the trace for given call site to the current caller trace *)
   val append : t -> t -> CallSite.t -> t
 
@@ -343,6 +345,21 @@ module Make (Spec : Spec) = struct
 
   let update_sinks t sinks = { t with sinks }
 
+  let get_footprint_index source =
+    match Source.get_footprint_access_path source with
+    | Some access_path ->
+        AccessPath.get_footprint_index access_path
+    | None ->
+        None
+
+  let get_footprint_indexes trace =
+    Sources.fold
+      (fun source acc -> match get_footprint_index source with
+         | Some footprint_index -> IntSet.add footprint_index acc
+         | None -> acc)
+      (sources trace)
+      IntSet.empty
+
   (** compute caller_trace + callee_trace *)
   let append caller_trace callee_trace callee_site =
     if is_empty callee_trace

infer/src/checkers/Trace.mli

@@ -78,6 +78,9 @@ module type S = sig
   (** replace sinks with new ones *)
   val update_sinks : t -> Sinks.t -> t
 
+  (** get the footprint indexes for all of the sources in the trace *)
+  val get_footprint_indexes : t -> IntSet.t
+
   (** append the trace for given call site to the current caller trace *)
   val append : t -> t -> CallSite.t -> t
 

infer/src/checkers/accessPath.ml

@@ -207,6 +207,14 @@ let to_footprint formal_index access_path =
   let _, base_typ = fst (extract access_path) in
   with_base (Var.of_formal_index formal_index, base_typ) access_path
 
+let get_footprint_index access_path =
+  let raw_access_path = extract access_path in
+  match raw_access_path with
+  | (Var.LogicalVar id, _), _ when Ident.is_footprint id ->
+      Some (Ident.get_stamp id)
+  | _ ->
+      None
+
 let is_exact = function
   | Exact _ -> true
   | Abstracted _ -> false

infer/src/checkers/accessPath.mli

@@ -77,6 +77,10 @@ val of_lhs_exp : Exp.t -> Typ.t -> f_resolve_id:(Var.t -> Raw.t option) -> Raw.t
 (** replace the base var with a footprint variable rooted at formal index [formal_index] *)
 val to_footprint : int -> t -> t
 
+(** return the formal index associated with the base of this access path if there is one, or None
+    otherwise *)
+val get_footprint_index : t -> int option
+
 (** append new accesses to an existing access path; e.g., `append_access x.f [g, h]` produces
     `x.f.g.h` *)
 val append : Raw.t -> access list -> Raw.t

infer/src/quandary/TaintAnalysis.ml

@@ -103,7 +103,7 @@ module Make (TaintSpecification : TaintSpec.S) = struct
           false
 
     (** log any new reportable source-sink flows in [trace] *)
-    let report_trace trace cur_site (proc_data : extras ProcData.t) =
+    let report_trace ?(sink_indexes=IntSet.empty) trace cur_site (proc_data : extras ProcData.t) =
       let get_summary pname =
         if Typ.Procname.equal pname (Procdesc.get_proc_name proc_data.pdesc)
         then
@@ -148,14 +148,13 @@ module Make (TaintSpecification : TaintSpec.S) = struct
               expand_source matching_source (choice :: report_acc, seen_acc')
           | [] ->
               acc in
-        let rec expand_sink sink0 ((report_acc, seen_acc) as acc) =
+        let rec expand_sink sink0 indexes0 ((report_acc, seen_acc) as acc) =
           let kind = Sink.kind sink0 in
           let call_site = Sink.call_site sink0 in
           let seen_acc' = CallSite.Set.add call_site seen_acc in
           let is_recursive sink =
             CallSite.Set.mem (Sink.call_site sink) seen_acc' in
           let matching_sinks =
-            (* TODO: use index info *)
             TaintDomain.trace_fold
               (fun acc _ trace ->
                  match List.find
@@ -164,17 +163,35 @@ module Make (TaintSpecification : TaintSpec.S) = struct
                                kind (Sink.kind sink) && not (is_recursive sink))
                          (Sinks.elements (sinks trace))
                  with
-                 | Some matching_sink -> matching_sink :: acc
-                 | None -> acc)
+                 | Some matching_sink ->
+                     let indexes_match = not
+                         (IntSet.is_empty (IntSet.inter indexes0 (get_footprint_indexes trace))) in
+                     (matching_sink, indexes_match) :: acc
+                 | None ->
+                     acc)
               (get_summary (CallSite.pname call_site))
               [] in
-          match matching_sinks with
-          | matching_sink :: _ ->
-              expand_sink matching_sink (matching_sink :: report_acc, seen_acc')
-          | [] ->
-              acc in
+          try
+            (* try to find a sink whose indexes match the current sink *)
+            let matching_sink, _ = List.find_exn ~f:snd matching_sinks in
+            expand_sink
+              matching_sink (Sink.indexes matching_sink) (matching_sink :: report_acc, seen_acc')
+          with Not_found ->
+            (* didn't find a sink whose indexes match; this can happen when taint flows in via a
+               global. pick any sink whose kind matches *)
+            begin
+              match matching_sinks with
+              | (matching_sink, _) :: _ ->
+                  expand_sink
+                    matching_sink
+                    (Sink.indexes matching_sink)
+                    (matching_sink :: report_acc, seen_acc')
+              | [] ->
+                  acc
+            end in
         let expanded_sources, _ = expand_source source ([None, source], CallSite.Set.empty) in
-        let expanded_sinks, _ = expand_sink sink ([sink], CallSite.Set.empty) in
+        let expanded_sinks, _ =
+          expand_sink sink sink_indexes ([sink], CallSite.Set.empty) in
         let source_trace =
           let pp_access_path_opt fmt = function
             | None -> F.fprintf fmt ""
@@ -223,7 +240,10 @@ module Make (TaintSpecification : TaintSpec.S) = struct
             begin
               match access_path_get_node actual_ap access_tree_acc proc_data with
               | Some (actual_trace, _) ->
-                  let actual_trace' = TraceDomain.add_sink sink actual_trace in
+                  let sink' =
+                    let indexes = TraceDomain.get_footprint_indexes actual_trace in
+                    TraceDomain.Sink.make ~indexes (TraceDomain.Sink.kind sink) callee_site in
+                  let actual_trace' = TraceDomain.add_sink sink' actual_trace in
                   report_trace actual_trace' callee_site proc_data;
                   TaintDomain.add_trace actual_ap actual_trace' access_tree_acc
               | None ->
@@ -299,8 +319,9 @@ module Make (TaintSpecification : TaintSpec.S) = struct
 
       let instantiate_and_report callee_trace caller_trace access_tree =
         let caller_trace' = replace_footprint_sources callee_trace caller_trace access_tree in
+        let sink_indexes = TraceDomain.get_footprint_indexes callee_trace in
         let appended_trace = TraceDomain.append caller_trace' callee_trace callee_site in
-        report_trace appended_trace callee_site proc_data;
+        report_trace appended_trace callee_site ~sink_indexes proc_data;
         appended_trace in
 
       let add_to_caller_tree access_tree_acc callee_ap callee_trace =

infer/tests/codetoanalyze/java/quandary/Traces.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2017 - present Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+package codetoanalyze.java.quandary;
+
+import com.facebook.infer.builtins.InferTaint;
+
+class Traces {
+  void sourceMethod() {
+    Obj source = (Obj) InferTaint.inferSecretSource();
+    callSameSink(null, source, null, null);
+  }
+
+  void callSameSink(Obj o1, Obj o2, Obj o3, Obj o4) {
+    callMySink(o1);
+    callMySinkIndirect(o2); // test that we expand this sink in the trace
+    callMySink(o3);
+    callMySink(o4);
+  }
+
+  void callMySinkIndirect(Obj o) {
+    callMySink(o);
+  }
+
+  void callMySink(Obj o) {
+    InferTaint.inferSensitiveSink(o);
+  }
+
+}

infer/tests/codetoanalyze/java/quandary/issues.exp

@@ -208,6 +208,7 @@ codetoanalyze/java/quandary/TaintedFormals.java, void TaintedFormals.taintedCont
 codetoanalyze/java/quandary/TaintedFormals.java, void TaintedFormals.taintedContextBad(String,Intent,Integer), 4, QUANDARY_TAINT_ERROR, [Return from void TaintedFormals.taintedContextBad(String,Intent,Integer),Call to void InferTaint.inferSensitiveSink(Object)]
 codetoanalyze/java/quandary/TaintedFormals.java, void TaintedFormals.taintedContextBad(String,Intent,Integer), 5, QUANDARY_TAINT_ERROR, [Return from void TaintedFormals.taintedContextBad(String,Intent,Integer),Call to void TaintedFormals.callSink(Object),Call to void InferTaint.inferSensitiveSink(Object)]
 codetoanalyze/java/quandary/TaintedFormals.java, void TaintedFormals.taintedContextBad(String,Intent,Integer), 6, QUANDARY_TAINT_ERROR, [Return from void TaintedFormals.taintedContextBad(String,Intent,Integer),Call to void TaintedFormals.callSink(Object),Call to void InferTaint.inferSensitiveSink(Object)]
+codetoanalyze/java/quandary/Traces.java, void Traces.sourceMethod(), 2, QUANDARY_TAINT_ERROR, [Return from Object InferTaint.inferSecretSource(),Call to void Traces.callSameSink(Obj,Obj,Obj,Obj),Call to void Traces.callMySinkIndirect(Obj),Call to void Traces.callMySink(Obj),Call to void InferTaint.inferSensitiveSink(Object)]
 codetoanalyze/java/quandary/UnknownCode.java, void UnknownCode.callPropagateFootprintBad(), 1, QUANDARY_TAINT_ERROR, [Return from Object InferTaint.inferSecretSource(),Call to void UnknownCode.propagateFootprint(String),Call to void InferTaint.inferSensitiveSink(Object)]
 codetoanalyze/java/quandary/UnknownCode.java, void UnknownCode.callUnknownSetterBad(Intent), 4, QUANDARY_TAINT_ERROR, [Return from Object InferTaint.inferSecretSource(),Call to void InferTaint.inferSensitiveSink(Object)]
 codetoanalyze/java/quandary/UnknownCode.java, void UnknownCode.propagateEmptyBad(), 6, QUANDARY_TAINT_ERROR, [Return from Object InferTaint.inferSecretSource(),Call to void InferTaint.inferSensitiveSink(Object)]