On Tue, Apr 06, 2021 at 11:38:25AM +0200, Hans Verkuil wrote:
> On 01/04/2021 14:33, Anirudh Rayabharam wrote:
> > syzbot has reported the following warning in pvr2_i2c_done:
> >
> > sysfs group 'power' not found for kobject '1-0043'
> >
> > When the device is disconnected (pvr_hdw_disconnect), the i2c adapter is
> > not unregistered along with the USB and vl42 teardown. As part of the
>
> vl42 -> v4l2
>
> > USB device disconnect, the sysfs files of the subdevices are also
> > deleted. So, by the time pvr_i2c_core_done is called by
> > pvr_context_destroy, the sysfs files have been deleted.
> >
> > To fix this, unregister the i2c adapter too in pvr_hdw_disconnect. Make
> > the device deregistration code shared by calling pvr_hdw_disconnect from
> > pvr2_hdw_destory.
>
> destory -> destroy
>
Ack, will fix these typos in v2.
> >
> > Reported-and-tested-by: syzbot+e74a998ca8f1df9cc332@xxxxxxxxxxxxxxxxxxxxxxxxx
> > Signed-off-by: Anirudh Rayabharam <mail@xxxxxxxxxxxxx>
> > ---
> > drivers/media/usb/pvrusb2/pvrusb2-hdw.c | 5 ++---
> > 1 file changed, 2 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/media/usb/pvrusb2/pvrusb2-hdw.c b/drivers/media/usb/pvrusb2/pvrusb2-hdw.c
> > index f4a727918e35..791227787ff5 100644
> > --- a/drivers/media/usb/pvrusb2/pvrusb2-hdw.c
> > +++ b/drivers/media/usb/pvrusb2/pvrusb2-hdw.c
> > @@ -2676,9 +2676,7 @@ void pvr2_hdw_destroy(struct pvr2_hdw *hdw)
> > pvr2_stream_destroy(hdw->vid_stream);
> > hdw->vid_stream = NULL;
> > }
> > - pvr2_i2c_core_done(hdw);
> > - v4l2_device_unregister(&hdw->v4l2_dev);
>
> I think this should still remain since pvr2_hdw_disconnect() doesn't call
> v4l2_device_unregister().
Then we might run into the same warning again. pvr2_hdw_disconnect()
calls pvr2_hdw_remove_usb_stuff() which calls v4l2_device_disconnect().
Perhaps there we should call v4l2_device_unregister() instead?
>
> Can you test that with syzbot?
Will do.
Thanks!
- Anirudh.
>
> Regards,
>
> Hans
>
> > - pvr2_hdw_remove_usb_stuff(hdw);
> > + pvr2_hdw_disconnect(hdw);
> > mutex_lock(&pvr2_unit_mtx);
> > do {
> > if ((hdw->unit_number >= 0) &&
> > @@ -2705,6 +2703,7 @@ void pvr2_hdw_disconnect(struct pvr2_hdw *hdw)
> > {
> > pvr2_trace(PVR2_TRACE_INIT,"pvr2_hdw_disconnect(hdw=%p)",hdw);
> > LOCK_TAKE(hdw->big_lock);
> > + pvr2_i2c_core_done(hdw);
> > LOCK_TAKE(hdw->ctl_lock);
> > pvr2_hdw_remove_usb_stuff(hdw);
> > LOCK_GIVE(hdw->ctl_lock);
> >
>
