On Thu, 2025-03-13 at 00:00 +0000, Qasim Ijaz wrote:

test_mb_mark_used() and test_mb_free_blocks() call kunit_kzalloc() to allocate memory, however both fail to ensure that the allocations succeeded. If kunit_kzalloc() returns NULL, then dereferencing the corresponding pointer without checking for NULL will lead to a NULL pointer dereference.

To fix this call KUNIT_ASSERT_NOT_ERR_OR_NULL() to ensure the allocation succeeded.

Reviewed-by: Tim Chen tim.c.chen@linux.intel.com

Fixes: ac96b56a2fbd ("ext4: Add unit test for mb_mark_used") Fixes: b7098e1fa7bc ("ext4: Add unit test for mb_free_blocks") Cc: stable@vger.kernel.org Signed-off-by: Qasim Ijaz qasdev00@gmail.com

---

fs/ext4/mballoc-test.c | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/fs/ext4/mballoc-test.c b/fs/ext4/mballoc-test.c index bb2a223b207c..d634c12f1984 100644 --- a/fs/ext4/mballoc-test.c +++ b/fs/ext4/mballoc-test.c @@ -796,6 +796,7 @@ static void test_mb_mark_used(struct kunit *test) KUNIT_ASSERT_NOT_ERR_OR_NULL(test, buddy); grp = kunit_kzalloc(test, offsetof(struct ext4_group_info, bb_counters[MB_NUM_ORDERS(sb)]), GFP_KERNEL);

• KUNIT_ASSERT_NOT_ERR_OR_NULL(test, grp);

ret = ext4_mb_load_buddy(sb, TEST_GOAL_GROUP, &e4b); KUNIT_ASSERT_EQ(test, ret, 0); @@ -860,6 +861,7 @@ static void test_mb_free_blocks(struct kunit *test) KUNIT_ASSERT_NOT_ERR_OR_NULL(test, buddy); grp = kunit_kzalloc(test, offsetof(struct ext4_group_info, bb_counters[MB_NUM_ORDERS(sb)]), GFP_KERNEL);

• KUNIT_ASSERT_NOT_ERR_OR_NULL(test, grp);

ret = ext4_mb_load_buddy(sb, TEST_GOAL_GROUP, &e4b); KUNIT_ASSERT_EQ(test, ret, 0);