From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751868AbbIORji (ORCPT ); Tue, 15 Sep 2015 13:39:38 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:34653 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751005AbbIORjh (ORCPT ); Tue, 15 Sep 2015 13:39:37 -0400 Message-ID: <55F857BE.6060201@oracle.com> Date: Tue, 15 Sep 2015 13:39:10 -0400 From: Sasha Levin User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Eric Dumazet CC: xeb@mail.ru, ebiederm@xmission.com, davem@davemloft.net, simon@farnz.org.uk, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] pptp: avoid releasing the sock too early References: <1442245229-31099-1-git-send-email-sasha.levin@oracle.com> <1442249027.14284.2.camel@edumazet-glaptop2.roam.corp.google.com> In-Reply-To: <1442249027.14284.2.camel@edumazet-glaptop2.roam.corp.google.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Source-IP: userv0022.oracle.com [156.151.31.74] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/14/2015 12:43 PM, Eric Dumazet wrote: > Hmm, is the synchronize_rcu() in del_chan() still needed, and why it was > not enough ? > > I believe your patch might reduce the race window, but it is not clear > it is the right fix. You're right, I've missed the synchronize_rcu() originally. At this point I'm certain that my patch is incorrect (so ignore it please), but I don't see the cause of the bug either. Let me think about it some more... Thanks, Sasha