Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-23 12:42:02 +00:00
Code Issues Packages Projects Releases Wiki Activity

kasan: test: add globals left-out-of-bounds test

Browse Source 
Add a test checking that KASAN generic can also detect out-of-bounds
accesses to the left of globals.

Unfortunately it seems that GCC doesn't catch this (tested GCC 10, 11).
The main difference between GCC's globals redzoning and Clang's is that
GCC relies on using increased alignment to producing padding, where
Clang's redzoning implementation actually adds real data after the
global and doesn't rely on alignment to produce padding.  I believe this
is the main reason why GCC can't reliably catch globals out-of-bounds in
this case.

Given this is now a known issue, to avoid failing the whole test suite,
skip this test case with GCC.

Link: https://lkml.kernel.org/r/20211117130714.135656-1-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Reported-by: Kaiwan N Billimoria <kaiwan.billimoria@gmail.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Kaiwan N Billimoria <kaiwan.billimoria@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Marco Elver 2022-01-14 14:04:51 -08:00 committed by Linus Torvalds
parent 14606001ef
commit e5f4728767
1 changed files with 17 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
lib/test_kasan.c
View File

@ -700,7 +700,7 @@ static void kmem_cache_bulk(struct kunit *test)
static char global_array[10];
static void kasan_global_oob(struct kunit *test)
static void kasan_global_oob_right(struct kunit *test)
{
/*
* Deliberate out-of-bounds access. To prevent CONFIG_UBSAN_LOCAL_BOUNDS
@ -723,6 +723,20 @@ static void kasan_global_oob(struct kunit *test)
KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
}
static void kasan_global_oob_left(struct kunit *test)
{
char *volatile array = global_array;
char *p = array - 3;
/*
* GCC is known to fail this test, skip it.
* See https://bugzilla.kernel.org/show_bug.cgi?id=215051.
*/
KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_CC_IS_CLANG);
KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
}
/* Check that ksize() makes the whole object accessible. */
static void ksize_unpoisons_memory(struct kunit *test)
{
@ -1162,7 +1176,8 @@ static struct kunit_case kasan_kunit_test_cases[] = {
KUNIT_CASE(kmem_cache_oob),
KUNIT_CASE(kmem_cache_accounted),
KUNIT_CASE(kmem_cache_bulk),
KUNIT_CASE(kasan_global_oob),
KUNIT_CASE(kasan_global_oob_right),
KUNIT_CASE(kasan_global_oob_left),
KUNIT_CASE(kasan_stack_oob),
KUNIT_CASE(kasan_alloca_oob_left),
KUNIT_CASE(kasan_alloca_oob_right),