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author | Andrey Konovalov <andreyknvl@google.com> | 2021-02-24 12:05:42 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-02-24 13:38:31 -0800 |
commit | e66e1799a76621003e5b04c9c057826a2152e103 (patch) | |
tree | fb71d26d81e767a8bd621b9843586f6843f73877 | |
parent | 1b1df4c4e2576f6b9c5b1f5f1fc9435e3f6c6b47 (diff) | |
download | linux-e66e1799a76621003e5b04c9c057826a2152e103.tar.bz2 |
kasan: fix memory corruption in kasan_bitops_tags test
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
Link: https://lkml.kernel.org/r/7d452ce4ae35bb1988d2c9244dfea56cf2cc9315.1610733117.git.andreyknvl@google.com
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>
-rw-r--r-- | lib/test_kasan.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/lib/test_kasan.c b/lib/test_kasan.c index 9a227d7e06d6..e59f185b8075 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); } |