Commit a942da24 authored by Dongliang Mu's avatar Dongliang Mu Committed by Gao Xiang
Browse files

fs: erofs: add sanity check for kobject in erofs_unregister_sysfs 

Syzkaller hit 'WARNING: kobject bug in erofs_unregister_sysfs'. This bug
is triggered by injecting fault in kobject_init_and_add of
erofs_unregister_sysfs.

Fix this by adding sanity check for kobject in erofs_unregister_sysfs

Note that I've tested the patch and the crash does not occur any more.

Link: https://lore.kernel.org/r/20220315132814.12332-1-dzm91@hust.edu.cn


Signed-off-by: default avatarDongliang Mu <mudongliangabcd@gmail.com>
Fixes: 168e9a76 ("erofs: add sysfs interface")
Reviewed-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: default avatarChao Yu <chao@kernel.org>
Signed-off-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
parent 9f2731d6

fs/erofs/sysfs.c

+5 −3
Original line number Diff line number Diff line
@@ -221,10 +221,12 @@ void erofs_unregister_sysfs(struct super_block *sb) 
{

	struct erofs_sb_info *sbi = EROFS_SB(sb);



	if (sbi->s_kobj.state_in_sysfs) {

		kobject_del(&sbi->s_kobj);

		kobject_put(&sbi->s_kobj);

		wait_for_completion(&sbi->s_kobj_unregister);

	}

}



int __init erofs_init_sysfs(void)

{