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| author | Dongliang Mu <mudongliangabcd@gmail.com> | 2022-03-15 21:28:14 +0800 |
|---|---|---|
| committer | Gao Xiang <hsiangkao@linux.alibaba.com> | 2022-03-17 00:09:02 +0800 |
| commit | a942da24abc5839c11a8fc2a4b7cb268ea94ba54 (patch) | |
| tree | d59244f6191e7e88eff52032abc6c9651aa7e20c | |
| parent | 9f2731d6338a072b60ab1d9340847bde3306614b (diff) | |
| download | lwn-a942da24abc5839c11a8fc2a4b7cb268ea94ba54.tar.gz lwn-a942da24abc5839c11a8fc2a4b7cb268ea94ba54.zip | |
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: Dongliang Mu <mudongliangabcd@gmail.com>
Fixes: 168e9a76200c ("erofs: add sysfs interface")
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
| -rw-r--r-- | fs/erofs/sysfs.c | 8 |
1 files 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) |