From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarek Poplawski Subject: Re: [PATCH 1/9] net classifier: dont allow filters on semi-classful qdisc Date: Sat, 07 Aug 2010 00:26:17 +0200 Message-ID: <4C5C8C09.9070206@gmail.com> References: <20100806193548.007978639@vyatta.com> <20100806193558.580890552@vyatta.com> <4C5C7D9F.4040303@gmail.com> <20100806145818.66d389eb@nehalam> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: David Miller , netdev@vger.kernel.org To: Stephen Hemminger Return-path: Received: from mail-bw0-f46.google.com ([209.85.214.46]:63676 "EHLO mail-bw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751782Ab0HFW0X (ORCPT ); Fri, 6 Aug 2010 18:26:23 -0400 Received: by bwz3 with SMTP id 3so254568bwz.19 for ; Fri, 06 Aug 2010 15:26:22 -0700 (PDT) In-Reply-To: <20100806145818.66d389eb@nehalam> Sender: netdev-owner@vger.kernel.org List-ID: Stephen Hemminger wrote, On 06.08.2010 23:58: > On Fri, 06 Aug 2010 23:24:47 +0200 > Jarek Poplawski wrote: > >> Stephen Hemminger wrote, On -10.01.-28163 20:59: >> >>> There are several qdisc which only support a single class (sfq, mq, tbf) >>> and the kernel would dereference a null pointer (bind_tcf), if a user >>> attempted to apply a filter one of these classes. >> >> >> mq and tbf can't have this issue because they don't have >> .tcf_chain class method. sfq should support it on purpose >> after this patch: >> >> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=7d2681a6ff4f9ab5e48d02550b4c6338f1638998 >> and needs tiny fix only. > > Probably best to fix both ways. Fix sfq to allow filters to > be chained, and fix API to prevent refuse to allow qdisc to > register with tcf_chain && !bind_tcf > Yes, but your patch needs a different changelog and I'm not sure it's necessary for stable (there should be no other such cases for now). Jarek P.