From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=46886 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OYdab-0006Nh-In for qemu-devel@nongnu.org; Tue, 13 Jul 2010 07:23:56 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OYdaU-0004Wy-04 for qemu-devel@nongnu.org; Tue, 13 Jul 2010 07:23:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59429) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OYdaT-0004Wp-QF for qemu-devel@nongnu.org; Tue, 13 Jul 2010 07:23:45 -0400 Date: Tue, 13 Jul 2010 14:23:42 +0300 From: Gleb Natapov Subject: Re: [Qemu-devel] Re: [PATCH RFC] e1000: fix access 4 bytes beyond buffer end Message-ID: <20100713112342.GB27473@redhat.com> References: <20100712174823.GA11411@redhat.com> <4C3B8409.9030202@codemonkey.ws> <20100712224254.GD13707@redhat.com> <4C3B9E84.3050809@codemonkey.ws> <20100713063549.GA5463@redhat.com> <20100713111110.GB3446@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100713111110.GB3446@redhat.com> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: alex.williamson@redhat.com, qemu-devel@nongnu.org On Tue, Jul 13, 2010 at 02:11:10PM +0300, Michael S. Tsirkin wrote: > On Tue, Jul 13, 2010 at 09:35:49AM +0300, Gleb Natapov wrote: > > On Mon, Jul 12, 2010 at 06:00:20PM -0500, Anthony Liguori wrote: > > > On 07/12/2010 05:42 PM, Michael S. Tsirkin wrote: > > > >On Mon, Jul 12, 2010 at 04:07:21PM -0500, Anthony Liguori wrote: > > > >>On 07/12/2010 12:48 PM, Michael S. Tsirkin wrote: > > > >>>We do range check for size, and get size as buffer, > > > >>>but copy size + 4 bytes (4 is for FCS). > > > >>>Let's copy size bytes but put size + 4 in length. > > > >>> > > > >>>Signed-off-by: Michael S. Tsirkin > > > >>I think I'd feel slightly better if we zero'd out the FCS before > > > >>writing it to the guest. It is potentially a data leak. > > > >> > > > >>Regards, > > > >> > > > >>Anthony Liguori > > > >I am guessing there's no chance guest actually looks > > > >at this data, otherwise it won't match and we'd get errors, right? > > > > > > That's my assumption too. Although I believe there are some known > > > issues with e1000 and certain versions of Windows and the Microsoft > > > built-in driver. Maybe this is why those drivers don't work and the > > > Intel drivers do? > > > > > At least one known issue with Windows drivers to me is that they > > sometimes (on resume from S4 at least) enable interrupts before setup > > irq routing, so if interrupt is generated in the wrong time it hangs the > > guest. I guess it works on real HW for them because line speed > > negotiation takes non-zero time. > > I guess we could work around this. Is there a bz? > BZ where? We do not support e1000 with Windows guests. -- Gleb.