From b91791d71c58d14309cd4d842d222f5d36b3a5a8 Mon Sep 17 00:00:00 2001 From: Nick Kralevich Date: Wed, 2 Oct 2013 14:14:40 -0700 Subject: [PATCH] Use alloc_size attribute on *alloc functions malloc and family were not declared with __attribute__((alloc_size)). This was (sometimes) preventing FORTIFY_SOURCE related functions from knowing the size of the buffer it's dealing with, inhibiting FORTIFY_SOURCE protections. Add __attribute__((alloc_size)) Information about the alloc_size attribute can be found at http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html Change-Id: Ia2f0a445f0170a7325f69259b5e7fb35a9f14921 --- libc/include/malloc.h | 12 ++++++------ tests/fortify_test.cpp | 14 ++++++++++++++ 2 files changed, 20 insertions(+), 6 deletions(-) diff --git a/libc/include/malloc.h b/libc/include/malloc.h index eaedc4925..9a4e32472 100644 --- a/libc/include/malloc.h +++ b/libc/include/malloc.h @@ -27,16 +27,16 @@ __BEGIN_DECLS -extern void* malloc(size_t byte_count) __mallocfunc __wur; -extern void* calloc(size_t item_count, size_t item_size) __mallocfunc __wur; -extern void* realloc(void* p, size_t byte_count) __wur; +extern void* malloc(size_t byte_count) __mallocfunc __wur __attribute__((alloc_size(1))); +extern void* calloc(size_t item_count, size_t item_size) __mallocfunc __wur __attribute__((alloc_size(1,2))); +extern void* realloc(void* p, size_t byte_count) __wur __attribute__((alloc_size(2))); extern void free(void* p); -extern void* memalign(size_t alignment, size_t byte_count) __mallocfunc __wur; +extern void* memalign(size_t alignment, size_t byte_count) __mallocfunc __wur __attribute__((alloc_size(2))); extern size_t malloc_usable_size(const void* p); -extern void* valloc(size_t byte_count) __mallocfunc __wur; -extern void* pvalloc(size_t byte_count) __mallocfunc __wur; +extern void* valloc(size_t byte_count) __mallocfunc __wur __attribute__((alloc_size(1))); +extern void* pvalloc(size_t byte_count) __mallocfunc __wur __attribute__((alloc_size(1))); #ifndef STRUCT_MALLINFO_DECLARED #define STRUCT_MALLINFO_DECLARED 1 diff --git a/tests/fortify_test.cpp b/tests/fortify_test.cpp index 4ea868b79..b131fbe07 100644 --- a/tests/fortify_test.cpp +++ b/tests/fortify_test.cpp @@ -20,6 +20,7 @@ #include #include #include +#include // We have to say "DeathTest" here so gtest knows to run this test (which exits) // in its own process. Unfortunately, the C preprocessor doesn't give us an @@ -395,6 +396,19 @@ TEST(DEATHTEST, sprintf_fortified) { ASSERT_EXIT(sprintf(buf, "%s", source_buf), testing::KilledBySignal(SIGABRT), ""); } +#ifndef __clang__ +// This test is disabled in clang because clang doesn't properly detect +// this buffer overflow. TODO: Fix clang. +TEST(DEATHTEST, sprintf_malloc_fortified) { + ::testing::FLAGS_gtest_death_test_style = "threadsafe"; + char* buf = (char *) malloc(10); + char source_buf[11]; + memcpy(source_buf, "1234567890", 11); + ASSERT_EXIT(sprintf(buf, "%s", source_buf), testing::KilledBySignal(SIGABRT), ""); + free(buf); +} +#endif + TEST(DEATHTEST, sprintf2_fortified) { ::testing::FLAGS_gtest_death_test_style = "threadsafe"; char buf[5];