Messages in this thread Patch in this message | | | From | Dongliang Mu <> | Subject | [PATCH] fs: erofs: add sanity check for kobject in erofs_unregister_sysfs | Date | Tue, 15 Mar 2022 21:28:14 +0800 |
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From: Dongliang Mu <mudongliangabcd@gmail.com>
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.
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com> --- fs/erofs/sysfs.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/fs/erofs/sysfs.c b/fs/erofs/sysfs.c index dac252bc9228..f3babf1e6608 100644 --- a/fs/erofs/sysfs.c +++ b/fs/erofs/sysfs.c @@ -221,9 +221,11 @@ void erofs_unregister_sysfs(struct super_block *sb) { struct erofs_sb_info *sbi = EROFS_SB(sb); - kobject_del(&sbi->s_kobj); - kobject_put(&sbi->s_kobj); - wait_for_completion(&sbi->s_kobj_unregister); + 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) -- 2.25.1
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