From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933030AbXDRI1m (ORCPT ); Wed, 18 Apr 2007 04:27:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933041AbXDRI1m (ORCPT ); Wed, 18 Apr 2007 04:27:42 -0400 Received: from mailhub.sw.ru ([195.214.233.200]:18618 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933030AbXDRI1l (ORCPT ); Wed, 18 Apr 2007 04:27:41 -0400 Message-ID: <4625D7A8.5030209@sw.ru> Date: Wed, 18 Apr 2007 12:32:40 +0400 From: Pavel Emelianov User-Agent: Thunderbird 1.5 (X11/20060317) MIME-Version: 1.0 To: Evgeniy Polyakov CC: David Miller , Linux Netdev List , Andrew Morton , Linux Kernel Mailing List , devel@openvz.org, Patrick McHardy , Kirill Korotaev Subject: Re: [NETLINK] Don't attach callback to a going-away netlink socket References: <4625D3D2.9030507@sw.ru> <20070418081707.GA29267@2ka.mipt.ru> In-Reply-To: <20070418081707.GA29267@2ka.mipt.ru> Content-Type: text/plain; charset=KOI8-R Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Evgeniy Polyakov wrote: > On Wed, Apr 18, 2007 at 12:16:18PM +0400, Pavel Emelianov (xemul@sw.ru) wrote: >> Sorry, I forgot to put netdev and David in Cc when I first sent it. >> >> There is a race between netlink_dump_start() and netlink_release() >> that can lead to the situation when a netlink socket with non-zero >> callback is freed. > > Out of curiosity, why not to fix a netlink_dump_start() to remove > callback in error path, since in 'no-error' path it removes it in Error path is not relevant here. The problem is that we keep a calback on a socket that is about to be freed. > netlink_dump(). > > And, btw, can release method be called while socket is being used, I > thought about proper reference counters should prevent this, but not > 100% sure with RCU dereferencing of the descriptor. >