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

Johan Hovold
2021-12-03T10:29:45Z

Hi Laurent,

On Wed, Oct 27, 2021 at 12:50:46AM +0300, Laurent Pinchart wrote:
> Hi Johan,
>
> 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?

Johan