From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Fastabend Subject: Re: [Patch net-next] net_sched: avoid calling tcf_unbind_filter() in call_rcu callback Date: Thu, 02 Oct 2014 11:04:50 -0700 Message-ID: <542D93C2.1010407@gmail.com> References: <1412118444-29179-1-git-send-email-xiyou.wangcong@gmail.com> <1412118444-29179-2-git-send-email-xiyou.wangcong@gmail.com> <20141001.220123.1054083748022563765.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: xiyou.wangcong@gmail.com, netdev@vger.kernel.org, john.r.fastabend@intel.com To: David Miller Return-path: Received: from mail-ob0-f177.google.com ([209.85.214.177]:38922 "EHLO mail-ob0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751208AbaJBSFD (ORCPT ); Thu, 2 Oct 2014 14:05:03 -0400 Received: by mail-ob0-f177.google.com with SMTP id uy5so1716716obc.22 for ; Thu, 02 Oct 2014 11:05:02 -0700 (PDT) In-Reply-To: <20141001.220123.1054083748022563765.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On 10/01/2014 07:01 PM, David Miller wrote: > From: Cong Wang > Date: Tue, 30 Sep 2014 16:07:24 -0700 > >> This fixes the following crash: > ... >> tp could be freed in call_rcu callback too, the order is not guaranteed. >> >> Cc: John Fastabend >> Signed-off-by: Cong Wang > > Applied, and I added John's description of why this is legal to the > commit message. > -- Thanks, I'll have another series shortly to fix the other classifiers with the same issue and pull 'tp' out of the ematch stuff. Passing around free'd pointers that never get used through the ematch code wont cause a crash but there is no reason to propagate it like this. .John -- John Fastabend Intel Corporation