Commit 22f53f08 authored by Ye Bin's avatar Ye Bin Committed by Theodore Ts'o
Browse files

ext4: fix possible null-ptr-deref in mbt_kunit_exit() 



There's issue as follows:
    # test_new_blocks_simple: failed to initialize: -12
KASAN: null-ptr-deref in range [0x0000000000000638-0x000000000000063f]
Tainted: [E]=UNSIGNED_MODULE, [N]=TEST
RIP: 0010:mbt_kunit_exit+0x5e/0x3e0 [ext4_test]
Call Trace:
 <TASK>
 kunit_try_run_case_cleanup+0xbc/0x100 [kunit]
 kunit_generic_run_threadfn_adapter+0x89/0x100 [kunit]
 kthread+0x408/0x540
 ret_from_fork+0xa76/0xdf0
 ret_from_fork_asm+0x1a/0x30

If mbt_kunit_init() init testcase failed will lead to null-ptr-deref.
So add test if 'sb' is inited success in mbt_kunit_exit().

Fixes: 7c9fa399 ("ext4: add first unit test for ext4_mb_new_blocks_simple in mballoc")
Signed-off-by: default avatarYe Bin <yebin10@huawei.com>
Reviewed-by: default avatarRitesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: default avatarOjaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/20260330133035.287842-6-yebin@huaweicloud.com


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent ca78c31a

fs/ext4/mballoc-test.c

+5 −1
Original line number Diff line number Diff line
@@ -362,7 +362,6 @@ static int mbt_kunit_init(struct kunit *test) 
		return ret;

	}



	test->priv = sb;

	kunit_activate_static_stub(test,

				   ext4_read_block_bitmap_nowait,

				   ext4_read_block_bitmap_nowait_stub);
@@ -383,6 +382,8 @@ static int mbt_kunit_init(struct kunit *test) 
		return -ENOMEM;

	}



	test->priv = sb;



	return 0;

}
@@ -390,6 +391,9 @@ static void mbt_kunit_exit(struct kunit *test) 
{

	struct super_block *sb = (struct super_block *)test->priv;



	if (!sb)

		return;



	mbt_mb_release(sb);

	mbt_ctx_release(sb);

	mbt_ext4_free_super_block(sb);