From: Andrey Konovalov andreyknvl@gmail.com
[ Upstream commit 555999a009aacd90ea51a6690e8eb2a5d0427edc ]
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/64fd457668a16e7b58d094f14a165f9d5170c5a9.162877980... 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 Signed-off-by: Sasha Levin sashal@kernel.org --- lib/test_kasan.c | 28 +++++++++++++++++----------- 1 file changed, 17 insertions(+), 11 deletions(-)
diff --git a/lib/test_kasan.c b/lib/test_kasan.c index ba7ba3962949..9a6eb3c9dc49 100644 --- a/lib/test_kasan.c +++ b/lib/test_kasan.c @@ -417,64 +417,70 @@ 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); }