Re: [PATCH V2] nilfs2: Fix reference count leak in nilfs_sysfs_create_device_group

[Ryusuke Konishi]

Hi Andrew,

This v2 patch was not CC'ed to you.   Could you please
pick it up from LKML?

Regards,
Ryusuke Konishi

On Thu, May 28, 2020 at 8:23 AM Ryusuke Konishi
<konishi.ryusuke@xxxxxxxxx> wrote:
>
> Hi Andrew,
>
> Please pick this up as well.
>
> Acked-by: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxx>
>
> On Thu, May 28, 2020 at 8:04 AM <wu000273@xxxxxxx> wrote:
> >
> > From: Qiushi Wu <wu000273@xxxxxxx>
> >
> > kobject_init_and_add() takes reference even when it fails.
> > In nilfs_sysfs_create_device_group(), the memory allocated by
> > kobject_init_and_add() is not freed when kobject_init_and_add()
> > fails. Fix this issue by calling kobject_put() to clean up the
> > kobject.
> >
> > Fixes: da7141fb78db ("nilfs2: add /sys/fs/nilfs2/<device> group")
> > Signed-off-by: Qiushi Wu <wu000273@xxxxxxx>
> > ---
> >  V2: using kobject_put() to handle kobject_init_and_add() instead of
> >  kobject_del().
> >
> >  fs/nilfs2/sysfs.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/fs/nilfs2/sysfs.c b/fs/nilfs2/sysfs.c
> > index e60be7bb55b0..8416f915d118 100644
> > --- a/fs/nilfs2/sysfs.c
> > +++ b/fs/nilfs2/sysfs.c
> > @@ -999,8 +999,10 @@ int nilfs_sysfs_create_device_group(struct super_block *sb)
> >         init_completion(&nilfs->ns_dev_kobj_unregister);
> >         err = kobject_init_and_add(&nilfs->ns_dev_kobj, &nilfs_dev_ktype, NULL,
> >                                     "%s", sb->s_id);
> > -       if (err)
> > +       if (err) {
> > +               kobject_put(&nilfs->ns_dev_kobj);
> >                 goto free_dev_subgroups;
> > +       }
> >
> >         err = nilfs_sysfs_create_mounted_snapshots_group(nilfs);
> >         if (err)
> > --
> > 2.17.1
> >