From: Greg KH <greg@kroah.com>
To: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Hans Verkuil <hverkuil@xs4all.nl>,
Dan Carpenter <dan.carpenter@oracle.com>,
linux-media@vger.kernel.org, kernel-janitors@vger.kernel.org,
stable@vger.kernel.org
Subject: Re: [patch -longterm] V4L/DVB: v4l2-ioctl: integer overflow in video_usercopy()
Date: Tue, 3 Jan 2012 12:55:39 -0800 [thread overview]
Message-ID: <20120103205539.GC17131@kroah.com> (raw)
In-Reply-To: <4EE9C2E6.1060304@infradead.org>
On Thu, Dec 15, 2011 at 07:50:30AM -0200, Mauro Carvalho Chehab wrote:
> On 15-12-2011 07:33, Hans Verkuil wrote:
> > On Thursday, December 15, 2011 10:21:41 Mauro Carvalho Chehab wrote:
> >> On 15-12-2011 04:34, Dan Carpenter wrote:
> >>> On a 32bit system the multiplication here could overflow. p->count is
> >>> used in some of the V4L drivers.
> >>
> >> ULONG_MAX / sizeof(v4l2_ext_control) is too much. This ioctl is used on things
> >> like setting MPEG paramenters, where several parameters need adjustments at
> >> the same time. I risk to say that 64 is probably a reasonably safe upper limit.
> >
> > Let's make it 1024. That gives more than enough room for expansion without taking
> > too much memory.
> >
> > Especially for video encoders a lot of controls are needed, and sensor drivers
> > are also getting more complex, so 64 is a bit too low for my taste.
> >
> > I agree that limiting this to some sensible value is a good idea.
>
> I'm fine with 1024. Yet, this could easily be changed to whatever upper value needed,
> and still be backward compatible.
Ok, can someone please send me the "accepted" version of this patch for
inclusion in the 2.6.32-stable tree?
thanks,
greg k-h
next prev parent reply other threads:[~2012-01-03 21:03 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-15 6:34 [patch -longterm] V4L/DVB: v4l2-ioctl: integer overflow in video_usercopy() Dan Carpenter
2011-12-15 9:21 ` Mauro Carvalho Chehab
2011-12-15 9:33 ` Hans Verkuil
2011-12-15 9:50 ` Mauro Carvalho Chehab
2012-01-03 20:55 ` Greg KH [this message]
2012-01-04 13:35 ` Dan Carpenter
2012-01-05 6:27 ` [patch -next] " Dan Carpenter
2012-01-05 6:28 ` [patch -longterm v2] " Dan Carpenter
2012-01-05 16:43 ` Greg KH
2012-01-05 17:56 ` Dan Carpenter
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