diff options
| author | Wang Wensheng <wsw9603@163.com> | 2026-05-24 11:10:53 +0800 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-05-28 21:31:26 -0700 |
| commit | b298cb5a2a6f54d4f1aff976416ea664983ee076 (patch) | |
| tree | 0204043ff59740af8668a2722b32db44cabdff8c /mm | |
| parent | 6c9885f59cfdbeb09993a4c716041161f5df5e88 (diff) | |
| download | linux-next-history-b298cb5a2a6f54d4f1aff976416ea664983ee076.tar.gz | |
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>
Diffstat (limited to 'mm')
| -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 32d06cbf6a310..3f4ed29178b3c 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); |