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| author | Andrey Konovalov <andreyknvl@gmail.com> | 2021-09-03 00:57:38 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-09-03 19:58:14 +0300 |
| commit | 555999a009aacd90ea51a6690e8eb2a5d0427edc (patch) | |
| tree | 5f3cc9a07efe6cc81277bb600074987f11fe14c4 /lib | |
| parent | 8fbad19bdcb4b9be8131536e5bb9616ab2e4eeb3 (diff) | |
| download | linux-555999a009aacd90ea51a6690e8eb2a5d0427edc.tar.xz | |
kasan: test: avoid corrupting memory via memset
kmalloc_oob_memset_*() tests do writes past the allocated objects. As the
result, they corrupt memory, which might lead to crashes with the HW_TAGS
mode, as it neither uses quarantine nor redzones.
Adjust the tests to only write memory within the aligned kmalloc objects.
Also add a comment mentioning that memset tests are designed to touch both
valid and invalid memory.
Link: https://lkml.kernel.org/r/64fd457668a16e7b58d094f14a165f9d5170c5a9.1628779805.git.andreyknvl@gmail.com
Signed-off-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/test_kasan.c | 28 |
1 files changed, 17 insertions, 11 deletions
diff --git a/lib/test_kasan.c b/lib/test_kasan.c index c82a82eb5393..db73bc9e3fa2 100644 --- a/lib/test_kasan.c +++ b/lib/test_kasan.c @@ -428,64 +428,70 @@ static void kmalloc_uaf_16(struct kunit *test) kfree(ptr1); } +/* + * Note: in the memset tests below, the written range touches both valid and + * invalid memory. This makes sure that the instrumentation does not only check + * the starting address but the whole range. + */ + static void kmalloc_oob_memset_2(struct kunit *test) { char *ptr; - size_t size = 8; + size_t size = 128 - KASAN_GRANULE_SIZE; ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); - KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + 7 + OOB_TAG_OFF, 0, 2)); + KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 1, 0, 2)); kfree(ptr); } static void kmalloc_oob_memset_4(struct kunit *test) { char *ptr; - size_t size = 8; + size_t size = 128 - KASAN_GRANULE_SIZE; ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); - KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + 5 + OOB_TAG_OFF, 0, 4)); + KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 3, 0, 4)); kfree(ptr); } - static void kmalloc_oob_memset_8(struct kunit *test) { char *ptr; - size_t size = 8; + size_t size = 128 - KASAN_GRANULE_SIZE; ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); - KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + 1 + OOB_TAG_OFF, 0, 8)); + KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 7, 0, 8)); kfree(ptr); } static void kmalloc_oob_memset_16(struct kunit *test) { char *ptr; - size_t size = 16; + size_t size = 128 - KASAN_GRANULE_SIZE; ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); - KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + 1 + OOB_TAG_OFF, 0, 16)); + KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 15, 0, 16)); kfree(ptr); } static void kmalloc_oob_in_memset(struct kunit *test) { char *ptr; - size_t size = 666; + size_t size = 128 - KASAN_GRANULE_SIZE; ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); - KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr, 0, size + 5 + OOB_TAG_OFF)); + KUNIT_EXPECT_KASAN_FAIL(test, + memset(ptr, 0, size + KASAN_GRANULE_SIZE)); kfree(ptr); } |