From: Greg Kroah-Hartman gregkh@linuxfoundation.org
From: Andrey Konovalov andreyknvl@google.com
[ Upstream commit e66e1799a76621003e5b04c9c057826a2152e103 ]
Since the hardware tag-based KASAN mode might not have a redzone that comes after an allocated object (when kasan.mode=prod is enabled), the kasan_bitops_tags() test ends up corrupting the next object in memory.
Change the test so it always accesses the redzone that lies within the allocated object's boundaries.
Link: https://linux-review.googlesource.com/id/I67f51d1ee48f0a8d0fe2658c2a39e4879f... Link: https://lkml.kernel.org/r/7d452ce4ae35bb1988d2c9244dfea56cf2cc9315.161073311... Signed-off-by: Andrey Konovalov andreyknvl@google.com Reviewed-by: Marco Elver elver@google.com Reviewed-by: Alexander Potapenko glider@google.com Cc: Andrey Ryabinin aryabinin@virtuozzo.com Cc: Branislav Rankov Branislav.Rankov@arm.com Cc: Catalin Marinas catalin.marinas@arm.com Cc: Dmitry Vyukov dvyukov@google.com Cc: Evgenii Stepanov eugenis@google.com Cc: Kevin Brodsky kevin.brodsky@arm.com Cc: Peter Collingbourne pcc@google.com Cc: Vincenzo Frascino vincenzo.frascino@arm.com Cc: Will Deacon will.deacon@arm.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- lib/test_kasan.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/lib/test_kasan.c b/lib/test_kasan.c index 2947274cc2d3..5a2f104ca13f 100644 --- a/lib/test_kasan.c +++ b/lib/test_kasan.c @@ -737,13 +737,13 @@ static void kasan_bitops_tags(struct kunit *test) return; }
- /* Allocation size will be rounded to up granule size, which is 16. */ - bits = kzalloc(sizeof(*bits), GFP_KERNEL); + /* kmalloc-64 cache will be used and the last 16 bytes will be the redzone. */ + bits = kzalloc(48, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bits);
- /* Do the accesses past the 16 allocated bytes. */ - kasan_bitops_modify(test, BITS_PER_LONG, &bits[1]); - kasan_bitops_test_and_modify(test, BITS_PER_LONG + BITS_PER_BYTE, &bits[1]); + /* Do the accesses past the 48 allocated bytes, but within the redone. */ + kasan_bitops_modify(test, BITS_PER_LONG, (void *)bits + 48); + kasan_bitops_test_and_modify(test, BITS_PER_LONG + BITS_PER_BYTE, (void *)bits + 48);
kfree(bits); }