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| author | Wang Wensheng <wsw9603@163.com> | 2026-05-24 06:10:53 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-06-05 00:45:02 +0300 |
| commit | 7c2ebe0fe06e84a5a1fcbc358111735080bdb141 (patch) | |
| tree | 85af5285435b3474fe28c0f44ac25a59e3b8cb41 | |
| parent | 7e6cc35f5283eab81a14231a64ecd640b690c48c (diff) | |
| download | linux-7c2ebe0fe06e84a5a1fcbc358111735080bdb141.tar.xz | |
kasan/test: only do kmalloc_double_kzfree for generic mode
kmalloc_double_kzfree() would corrupt kernel memory when the just freed
memory were allocated by another thread before the second call to
kfree_sensitive() and the new allocation tag happened to match the old
one.
This could not happen in GENERIC mode as it uses quarantine.
Link: https://lore.kernel.org/20260524031053.381776-1-wsw9603@163.com
Signed-off-by: Wang Wensheng <wsw9603@163.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | mm/kasan/kasan_test_c.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/mm/kasan/kasan_test_c.c b/mm/kasan/kasan_test_c.c index 32d06cbf6a31..3f4ed29178b3 100644 --- a/mm/kasan/kasan_test_c.c +++ b/mm/kasan/kasan_test_c.c @@ -874,6 +874,16 @@ static void kmalloc_double_kzfree(struct kunit *test) char *ptr; size_t size = 16; + /* + * With the tag-based KASAN modes, if the memory happens to be + * reallocated between the two frees and the new allocation tag happens + * to match the old one, the second free will cause a memory corruption. + * Resolving https://bugzilla.kernel.org/show_bug.cgi?id=212177 would + * help to deal with this. With Generic KASAN, it's effectively + * impossible for the memory to get reallocated due to the quarantine. + */ + KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC); + ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); |