diff options
| author | Kees Cook <keescook@chromium.org> | 2021-11-05 13:36:12 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-11-06 13:30:33 -0700 |
| commit | d73dad4eb5ad8c31ac9cf358eb5a55825bafe706 (patch) | |
| tree | 34585db952518be749bae401a60156977f93b540 /lib/test_kasan.c | |
| parent | 8772716f96704c67b1e2a6ba175605b4fce2a252 (diff) | |
| download | lwn-d73dad4eb5ad8c31ac9cf358eb5a55825bafe706.tar.gz lwn-d73dad4eb5ad8c31ac9cf358eb5a55825bafe706.zip | |
kasan: test: bypass __alloc_size checks
Intentional overflows, as performed by the KASAN tests, are detected at
compile time[1] (instead of only at run-time) with the addition of
__alloc_size. Fix this by forcing the compiler into not being able to
trust the size used following the kmalloc()s.
[1] https://lore.kernel.org/lkml/20211005184717.65c6d8eb39350395e387b71f@linux-foundation.org
Link: https://lkml.kernel.org/r/20211006181544.1670992-1-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/test_kasan.c')
| -rw-r--r-- | lib/test_kasan.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/lib/test_kasan.c b/lib/test_kasan.c index aa8e42250219..5475fe396ff7 100644 --- a/lib/test_kasan.c +++ b/lib/test_kasan.c @@ -440,6 +440,7 @@ static void kmalloc_oob_memset_2(struct kunit *test) ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); + OPTIMIZER_HIDE_VAR(size); KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 1, 0, 2)); kfree(ptr); } @@ -452,6 +453,7 @@ static void kmalloc_oob_memset_4(struct kunit *test) ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); + OPTIMIZER_HIDE_VAR(size); KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 3, 0, 4)); kfree(ptr); } @@ -464,6 +466,7 @@ static void kmalloc_oob_memset_8(struct kunit *test) ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); + OPTIMIZER_HIDE_VAR(size); KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 7, 0, 8)); kfree(ptr); } @@ -476,6 +479,7 @@ static void kmalloc_oob_memset_16(struct kunit *test) ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); + OPTIMIZER_HIDE_VAR(size); KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 15, 0, 16)); kfree(ptr); } @@ -488,6 +492,7 @@ static void kmalloc_oob_in_memset(struct kunit *test) ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); + OPTIMIZER_HIDE_VAR(size); KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr, 0, size + KASAN_GRANULE_SIZE)); kfree(ptr); @@ -497,7 +502,7 @@ static void kmalloc_memmove_negative_size(struct kunit *test) { char *ptr; size_t size = 64; - volatile size_t invalid_size = -2; + size_t invalid_size = -2; /* * Hardware tag-based mode doesn't check memmove for negative size. @@ -510,6 +515,7 @@ static void kmalloc_memmove_negative_size(struct kunit *test) KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); memset((char *)ptr, 0, 64); + OPTIMIZER_HIDE_VAR(invalid_size); KUNIT_EXPECT_KASAN_FAIL(test, memmove((char *)ptr, (char *)ptr + 4, invalid_size)); kfree(ptr); |