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://lkml.kernel.org/r/0c51a7266ea851797dc9816405fc40d860a48db1.1609871239.git.andreyknvl@xxxxxxxxxx
Link: https://linux-review.googlesource.com/id/I67f51d1ee48f0a8d0fe2658c2a39e4879fe0832a
Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Cc: 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: Marco Elver <elver@xxxxxxxxxx>
Cc: Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/test_kasan.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
--- a/lib/test_kasan.c~kasan-fix-memory-corruption-in-kasan_bitops_tags-test
+++ a/lib/test_kasan.c
@@ -771,17 +771,17 @@ static void kasan_bitops_tags(struct kun
/* This test is specifically crafted for the tag-based mode. */
if (IS_ENABLED(CONFIG_KASAN_GENERIC)) {
- kunit_info(test, "skipping, CONFIG_KASAN_SW_TAGS required");
+ kunit_info(test, "skipping, CONFIG_KASAN_SW/HW_TAGS required");
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);
}
_
Patches currently in -mm which might be from andreyknvl@xxxxxxxxxx are
kasan-prefix-exported-functions-with-kasan_.patch
kasan-clarify-hw_tags-impact-on-tbi.patch
kasan-clean-up-comments-in-tests.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-adopt-kmalloc_uaf2-test-to-hw_tags-mode.patch
kasan-fix-memory-corruption-in-kasan_bitops_tags-test.patch
kasan-fix-bug-detection-via-ksize-for-hw_tags-mode.patch
kasan-add-proper-page-allocator-tests.patch
