Messages in this thread | | | Date | Tue, 15 Mar 2022 18:43:01 +0800 | Subject | Re: [PATCH] fs: erofs: remember if kobject_init_and_add was done | From | Huang Jianan <> |
| |
在 2022/3/15 15:51, Dongliang Mu 写道: > 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 remembering if kobject_init_and_add is successful. > > Note that I've tested the patch and the crash does not occur any more. > > Reported-by: syzkaller <syzkaller@googlegroups.com> > Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com> > --- > fs/erofs/internal.h | 1 + > fs/erofs/sysfs.c | 9 ++++++--- > 2 files changed, 7 insertions(+), 3 deletions(-) > > diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h > index 5aa2cf2c2f80..9e20665e3f68 100644 > --- a/fs/erofs/internal.h > +++ b/fs/erofs/internal.h > @@ -144,6 +144,7 @@ struct erofs_sb_info { > u32 feature_incompat; > > /* sysfs support */ > + bool s_sysfs_inited;
Hi Dongliang,
How about using sbi->s_kobj.state_in_sysfs to avoid adding a extra member in sbi ?
Thanks, Jianan
> struct kobject s_kobj; /* /sys/fs/erofs/<devname> */ > struct completion s_kobj_unregister; > }; > diff --git a/fs/erofs/sysfs.c b/fs/erofs/sysfs.c > index dac252bc9228..2b48a4df19b4 100644 > --- a/fs/erofs/sysfs.c > +++ b/fs/erofs/sysfs.c > @@ -209,6 +209,7 @@ int erofs_register_sysfs(struct super_block *sb) > "%s", sb->s_id); > if (err) > goto put_sb_kobj; > + sbi->s_sysfs_inited = true; > return 0; > > put_sb_kobj: > @@ -221,9 +222,11 @@ 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_sysfs_inited) { > + kobject_del(&sbi->s_kobj); > + kobject_put(&sbi->s_kobj); > + wait_for_completion(&sbi->s_kobj_unregister); > + } > } > > int __init erofs_init_sysfs(void)
| |