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kasan: add another use-after-free test

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Add a new use-after-free test that checks that KASAN detects
use-after-free when another object was allocated in the same slot.

This test is mainly relevant for the tag-based modes, which do not use
quarantine.

Once [1] is resolved, this test can be extended to check that the stack
traces in the report point to the proper kmalloc/kfree calls.

[1] https://bugzilla.kernel.org/show_bug.cgi?id=212203

Link: https://lkml.kernel.org/r/0659cfa15809dd38faa02bc0a59d0b5dbbd81211.1662411800.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Andrey Konovalov 2022-09-05 23:05:49 +02:00 committed by Andrew Morton
parent 1f538e1f2d
commit 34b592ce5c
1 changed files with 24 additions and 0 deletions
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24
lib/test_kasan.c
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@ -612,6 +612,29 @@ again:
kfree(ptr2);
}
/*
* Check that KASAN detects use-after-free when another object was allocated in
* the same slot. Relevant for the tag-based modes, which do not use quarantine.
*/
static void kmalloc_uaf3(struct kunit *test)
{
char *ptr1, *ptr2;
size_t size = 100;
/* This test is specifically crafted for tag-based modes. */
KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
ptr1 = kmalloc(size, GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
kfree(ptr1);
ptr2 = kmalloc(size, GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
kfree(ptr2);
KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr1)[8]);
}
static void kfree_via_page(struct kunit *test)
{
char *ptr;
@ -1382,6 +1405,7 @@ static struct kunit_case kasan_kunit_test_cases[] = {
KUNIT_CASE(kmalloc_uaf),
KUNIT_CASE(kmalloc_uaf_memset),
KUNIT_CASE(kmalloc_uaf2),
KUNIT_CASE(kmalloc_uaf3),
KUNIT_CASE(kfree_via_page),
KUNIT_CASE(kfree_via_phys),
KUNIT_CASE(kmem_cache_oob),