From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wei Liu Subject: Re: [PATCH 6/6] xen-netback: don't disconnect frontend when seeing oversize frame Date: Mon, 25 Mar 2013 12:00:07 +0000 Message-ID: <20130325120007.GA21271@zion.uk.xensource.com> References: <1364209702-12437-1-git-send-email-wei.liu2@citrix.com> <1364209702-12437-7-git-send-email-wei.liu2@citrix.com> <51503945.6040204@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: "xen-devel@lists.xen.org" , "netdev@vger.kernel.org" , Ian Campbell , "annie.li@oracle.com" , "konrad.wilk@oracle.com" To: David Vrabel Return-path: Received: from smtp02.citrix.com ([66.165.176.63]:25346 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756704Ab3CYMAJ (ORCPT ); Mon, 25 Mar 2013 08:00:09 -0400 Content-Disposition: inline In-Reply-To: <51503945.6040204@citrix.com> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, Mar 25, 2013 at 11:47:17AM +0000, David Vrabel wrote: > On 25/03/13 11:08, Wei Liu wrote: > > Some buggy frontends may generate frames larger than 64 KiB. We should > > aggresively consume all slots and drop the packet instead of disconnecting the > > frontend. > > The following is the changeset description I wrote internally. It's a > bit more descriptive. > > Apologies for not sending out a proper patch in the first place. > > "Some frontend drivers are sending packets >= 64 KiB in length. This > length overflows the length field in the first frag making the > following frags have an invalid length ("Frag is bigger than frame"). > > Turn this error back into a non-fatal error by dropping the packet. > To avoid having the following frags having fatal errors, consume all > frags in the packet. > > This does not reopen the security hole as if the packet as an invalid > number of frags it will still hit this fatal error case." > Thanks. Overall this looks good. I will need to change 'frags' to 'slots' though. Wei. > David