On Wed, Jan 15, 2020 at 09:01:17PM +0300, Dan Carpenter wrote:
> On Wed, Jan 15, 2020 at 05:32:26PM +0000, Sean Young wrote:
> > Hello,
> >
> > On Tue, Dec 03, 2019 at 07:41:38AM +0700, Phong Tran wrote:
> > > For fixing syzbot "KMSAN: uninit-value in digitv_rc_query"
> > >
> > > In scenario testing for syzbot, failure reading from
> > > digitv_ctrl_msg() [1].
> > >
> > > Eg:
> > > [ 91.846657][ T3844] dvb-usb: bulk message failed: -22 (7/0)
> > >
> > > digitv_rc_query() always return 0. But in this case a wrong thing happens.
> > >
> > > Reported-by: syzbot+6bf9606ee955b646c0e1@xxxxxxxxxxxxxxxxxxxxxxxxx
> > > Tested-by: syzbot+6bf9606ee955b646c0e1@xxxxxxxxxxxxxxxxxxxxxxxxx
> >
> > A fix for this was already merged I'm afraid, see commit eecc70d22ae5
> > ("media: digitv: don't continue if remote control state can't be read").
> >
> > > [1]: https://syzkaller.appspot.com/text?tag=CrashLog&x=16860a63600000
> > > [2]: https://groups.google.com/d/msg/syzkaller-bugs/-TXIJAZ0J9Q/T4PEUQoeAQAJ
> > >
> > > Signed-off-by: Phong Tran <tranmanphong@xxxxxxxxx>
> > > ---
> > > drivers/media/usb/dvb-usb/digitv.c | 12 ++++++++----
> > > 1 file changed, 8 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/drivers/media/usb/dvb-usb/digitv.c b/drivers/media/usb/dvb-usb/digitv.c
> > > index dd5bb230cec1..61bc8945e6b9 100644
> > > --- a/drivers/media/usb/dvb-usb/digitv.c
> > > +++ b/drivers/media/usb/dvb-usb/digitv.c
> > > @@ -231,17 +231,21 @@ static struct rc_map_table rc_map_digitv_table[] = {
> > > static int digitv_rc_query(struct dvb_usb_device *d, u32 *event, int *state)
> > > {
> > > int i;
> > > - u8 key[5];
> > > + u8 key[5] = { 0 };
> >
> > The merged commit does not change this line. Why was this changed?
> >
>
> It would fix the problem that key[0] is never initialized... But the
> correct fix is to make key 4 elements long and delete key[0].
Phong,
Presumably you can fix this? You will have to renumber key[1] to
key[0] and key[2] to key[1] etc... Add a fixes tag.
Fixes: 774c0de4aed4 ("V4L/DVB (4616): [PATCH] Nebula DigiTV USB RC support")
Otherwise if you want I can send the patch.
regards,
dan carpenter
