The patch titled
Subject: kasan: fix memory corruption in kasan_bitops_tags test
has been added to the -mm tree. Its filename is
kasan-fix-memory-corruption-in-kasan_bitops_tags-test.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/kasan-fix-memory-corruption-in-kasan_bitops_tags-test.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/kasan-fix-memory-corruption-in-kasan_bitops_tags-test.patch
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------------------------------------------------------
From: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Subject: 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@xxxxxxxxxx
Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Reviewed-by: Marco Elver <elver@xxxxxxxxxx>
Reviewed-by: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: Branislav Rankov <Branislav.Rankov@xxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Evgenii Stepanov <eugenis@xxxxxxxxxx>
Cc: Kevin Brodsky <kevin.brodsky@xxxxxxx>
Cc: Peter Collingbourne <pcc@xxxxxxxxxx>
Cc: Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/test_kasan.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
--- a/lib/test_kasan.c~kasan-fix-memory-corruption-in-kasan_bitops_tags-test
+++ a/lib/test_kasan.c
@@ -749,13 +749,13 @@ static void kasan_bitops_tags(struct kun
/* 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);
}
_
Patches currently in -mm which might be from andreyknvl@xxxxxxxxxx are
kasan-fix-hw_tags-boot-parameters.patch
kasan-prefix-global-functions-with-kasan_.patch
kasan-clarify-hw_tags-impact-on-tbi.patch
kasan-clean-up-comments-in-tests.patch
kasan-add-macros-to-simplify-checking-test-constraints.patch
kasan-add-match-all-tag-tests.patch
kasan-arm64-allow-using-kunit-tests-with-hw_tags-mode.patch
kasan-rename-config_test_kasan_module.patch
kasan-add-compiler-barriers-to-kunit_expect_kasan_fail.patch
kasan-adapt-kmalloc_uaf2-test-to-hw_tags-mode.patch
kasan-fix-memory-corruption-in-kasan_bitops_tags-test.patch
kasan-move-_ret_ip_-to-inline-wrappers.patch
kasan-fix-bug-detection-via-ksize-for-hw_tags-mode.patch
kasan-add-proper-page-allocator-tests.patch
kasan-add-a-test-for-kmem_cache_alloc-free_bulk.patch
kasan-dont-run-tests-when-kasan-is-not-enabled.patch
