[PATCH RFC v3 05/10] selftests: openat2: add 0xFF poisoned data after misaligned struct

From: Aleksa Sarai
Date: Wed Oct 09 2024 - 16:45:12 EST


We should also verify that poisoned data after a misaligned struct is
also handled correctly by is_zeroed_user(). This test passes with no
kernel changes needed, so is_zeroed_user() was correct already.

Fixes: b28a10aedcd4 ("selftests: add openat2(2) selftests")
Signed-off-by: Aleksa Sarai <cyphar@xxxxxxxxxx>
---
tools/testing/selftests/openat2/openat2_test.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/openat2/openat2_test.c b/tools/testing/selftests/openat2/openat2_test.c
index 5790ab446527..4ca175a16ad6 100644
--- a/tools/testing/selftests/openat2/openat2_test.c
+++ b/tools/testing/selftests/openat2/openat2_test.c
@@ -112,9 +112,9 @@ void test_openat2_struct(void)
*
* This is effectively to check that is_zeroed_user() works.
*/
- copy = malloc(misalign + sizeof(how_ext));
+ copy = malloc(misalign*2 + sizeof(how_ext));
how_copy = copy + misalign;
- memset(copy, 0xff, misalign);
+ memset(copy, 0xff, misalign*2 + sizeof(how_ext));
memcpy(how_copy, &how_ext, sizeof(how_ext));
}


--
2.46.1