On Tue, Mar 15, 2022 at 09:28:14PM +0800, Dongliang Mu wrote: > From: Dongliang Mu <[email protected]> > > 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 <[email protected]>
Reviewed-by: Gao Xiang <[email protected]> Thanks, Gao Xiang > --- > 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
