[PATCH] D29602: [libFuzzer] Fix Load test.

[Marcos Pividori via Phabricator via llvm-commits]

mpividori created this revision.

We should ensure the size of the variable `a` is 8 bytes. Otherwise, this generates a stack buffer overflow inside the `memcpy` call in 32 bits machines. (We write more bytes than the size of a, when it is 4 bytes).


https://reviews.llvm.org/D29602

Files:
  lib/Fuzzer/test/LoadTest.cpp


Index: lib/Fuzzer/test/LoadTest.cpp
===================================================================
--- lib/Fuzzer/test/LoadTest.cpp
+++ lib/Fuzzer/test/LoadTest.cpp
@@ -14,7 +14,7 @@
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
   if (Size < 8) return 0;
-  size_t a = 0;
+  uint64_t a = 0;
   memcpy(&a, Data, 8);
   Sink = array[a % (kArraySize + 1)];
   return 0;


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