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| author | Arnd Bergmann <arnd@arndb.de> | 2024-02-12 12:15:52 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-02-22 19:24:58 +0100 |
| commit | e10aea105e9ed14b62a11844fec6aaa87c6935a3 (patch) | |
| tree | 11f63b44802d64e28422ecc7c82adfea2598d83c /mm/kasan | |
| parent | mm: document memalloc_noreclaim_save() and memalloc_pin_save() (diff) | |
| download | linux-e10aea105e9ed14b62a11844fec6aaa87c6935a3.tar.xz linux-e10aea105e9ed14b62a11844fec6aaa87c6935a3.zip | |
kasan/test: avoid gcc warning for intentional overflow
The out-of-bounds test allocates an object that is three bytes too short
in order to validate the bounds checking. Starting with gcc-14, this
causes a compile-time warning as gcc has grown smart enough to understand
the sizeof() logic:
mm/kasan/kasan_test.c: In function 'kmalloc_oob_16':
mm/kasan/kasan_test.c:443:14: error: allocation of insufficient size '13' for type 'struct <anonymous>' with size '16' [-Werror=alloc-size]
443 | ptr1 = kmalloc(sizeof(*ptr1) - 3, GFP_KERNEL);
| ^
Hide the actual computation behind a RELOC_HIDE() that ensures
the compiler misses the intentional bug.
Link: https://lkml.kernel.org/r/20240212111609.869266-1-arnd@kernel.org
Fixes: 3f15801cdc23 ("lib: add kasan test module")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/kasan')
| -rw-r--r-- | mm/kasan/kasan_test.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/kasan/kasan_test.c b/mm/kasan/kasan_test.c index 318d9cec111a..2d8ae4fbe63b 100644 --- a/mm/kasan/kasan_test.c +++ b/mm/kasan/kasan_test.c @@ -440,7 +440,8 @@ static void kmalloc_oob_16(struct kunit *test) /* This test is specifically crafted for the generic mode. */ KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC); - ptr1 = kmalloc(sizeof(*ptr1) - 3, GFP_KERNEL); + /* RELOC_HIDE to prevent gcc from warning about short alloc */ + ptr1 = RELOC_HIDE(kmalloc(sizeof(*ptr1) - 3, GFP_KERNEL), 0); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1); ptr2 = kmalloc(sizeof(*ptr2), GFP_KERNEL); |