Re: [PATCH] media: uvcvideo: fix division by zero at stream start

Laurent Pinchart
2021-12-03T10:52:49Z

Hi Johan,

On Fri, Dec 03, 2021 at 11:29:07AM +0100, Johan Hovold wrote:
> On Wed, Oct 27, 2021 at 12:50:46AM +0300, Laurent Pinchart wrote:
> > On Tue, Oct 26, 2021 at 02:06:55PM +0200, Johan Hovold wrote:
> > > On Tue, Oct 26, 2021 at 02:15:20PM +0300, Laurent Pinchart wrote:
> > > > On Tue, Oct 26, 2021 at 11:55:05AM +0100, Kieran Bingham wrote:
> > > > > Quoting Johan Hovold (2021-10-26 10:55:11)
> > > > > > Add the missing bulk-endpoint max-packet sanity check to probe() to
> > > > > > avoid division by zero in uvc_alloc_urb_buffers() in case a malicious
> > > > > > device has broken descriptors (or when doing descriptor fuzz testing).
> > > > > >
> > > > > > Note that USB core will reject URBs submitted for endpoints with zero
> > > > > > wMaxPacketSize but that drivers doing packet-size calculations still
> > > > > > need to handle this (cf. commit 2548288b4fb0 ("USB: Fix: Don't skip
> > > > > > endpoint descriptors with maxpacket=0")).
> > > > > >
> > > > > > Fixes: c0efd232929c ("V4L/DVB (8145a): USB Video Class driver")
> > > > > > Cc: stable@vger.kernel.org # 2.6.26
> > > > > > Signed-off-by: Johan Hovold <johan@kernel.org>
> > >
> > > Note however the copy-paste error in the commit message mentioning
> > > probe(), which is indeed where this would typically be handled.
> > >
> > > Do you want me to resend or can you change
> > >
> > > s/probe()/uvc_video_start_transfer()/
> > >
> > > in the commit message when applying if you think this is acceptable as
> > > is?
> >
> > I can fix this when applying.
> >
> > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>
> I noticed that this one hasn't showed up in linux-next yet. Do you still
> have it in your queue or do you want me to resend?

It should be in Mauro's queue now:

https://lore.kernel.org/all/YacOun3Diggsi05V@pendragon.ideasonboard.com/

--
Regards,

Laurent Pinchart