From mboxrd@z Thu Jan 1 00:00:00 1970 From: jamal Subject: Re: [BUG] net_cls: Panic occured when net_cls subsystem use Date: Mon, 01 Jun 2009 18:06:03 -0400 Message-ID: <1243893963.3966.325.camel@dogo.mojatatu.com> References: <1243604796.3966.21.camel@dogo.mojatatu.com> <1243605269.3966.28.camel@dogo.mojatatu.com> <20090529225929.GD2753@ami.dom.local> <1243684218.3966.83.camel@dogo.mojatatu.com> <20090531081213.GC2756@ami.dom.local> <1243776293.3966.241.camel@dogo.mojatatu.com> <20090531195557.GA2777@ami.dom.local> <1243813216.3966.254.camel@dogo.mojatatu.com> <20090601060638.GA4256@ff.dom.local> <1243861410.3966.268.camel@dogo.mojatatu.com> <20090601204957.GA2760@ami.dom.local> Reply-To: hadi@cyberus.ca Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Minoru Usui , netdev@vger.kernel.org, containers@lists.linux-foundation.org To: Jarek Poplawski Return-path: Received: from qw-out-2122.google.com ([74.125.92.25]:10745 "EHLO qw-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752698AbZFAWHD (ORCPT ); Mon, 1 Jun 2009 18:07:03 -0400 Received: by qw-out-2122.google.com with SMTP id 5so5295068qwd.37 for ; Mon, 01 Jun 2009 15:07:05 -0700 (PDT) In-Reply-To: <20090601204957.GA2760@ami.dom.local> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, 2009-06-01 at 22:49 +0200, Jarek Poplawski wrote: > > Actually, I'd insist with the old rock and handling that other rude > u32 case, at least until it's fixed in place. So I attach my version > of your patch (additionally I removed a pair of braces because of > checkpatch warning). Sure, it doesnt complicate anything - Minoru, this is the version to go for. > Alas, I still think we don't need to change so much in -stable to > fix the cls_cgroup oops, so I attach a patch which I think is > enough for -stable and probably -net too. It could be "reverted" > in -net-next just after applying cls_api patch. Of course, treat > it only as my humble proposal, and feel free to recommend to David > your version, no problem (really). My view is the same - that the second patch doesnt fix the root cause; and it is not that complicated to fix the root cause. So I humbly disagree with you. The issue is that a classifer (cls_group in this example) is being misconfigured. It rejects the config - but the tp has already been added. It then tries to use the tp in the fast and fails. If you look as closely as you did with the patch i posted, youd find ways to construct similar hostile misconfigs for other classifiers. You just need to create the scenario where the attributes will fail to validate. I actually suspect the most common scenario for such a failure is not that head is null (I doubt in Minoru case that allocation will fail); rather it is some reference to head->something. cheers, jamal