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/I67f51d1ee48f0a8d0fe2658c2a39e4879fe0832a Reviewed-by: Marco Elver <elver@xxxxxxxxxx> Reviewed-by: Alexander Potapenko <glider@xxxxxxxxxx> Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> --- 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 0cda4a1ff394..a06e7946f581 100644 --- a/lib/test_kasan.c +++ b/lib/test_kasan.c @@ -749,13 +749,13 @@ static void kasan_bitops_tags(struct kunit *test) /* This test is specifically crafted for tag-based modes. */ KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC); - /* 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); } -- 2.30.0.284.gd98b1dd5eaa7-goog
