From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pablo Neira Ayuso Subject: Re: [PATCH] netfilter: fix ->nfnl NULL oops Date: Wed, 9 Nov 2011 15:35:10 +0100 Message-ID: <20111109143510.GB24158@1984> References: <20111108221634.GA13261@p183.telecom.by> <32FF200DF1281ACA19CF3807@nimrod.local> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Alexey Dobriyan , kaber@trash.net, netfilter-devel@vger.kernel.org To: Alex Bligh Return-path: Received: from mail.us.es ([193.147.175.20]:50916 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752746Ab1KIOfM (ORCPT ); Wed, 9 Nov 2011 09:35:12 -0500 Content-Disposition: inline In-Reply-To: <32FF200DF1281ACA19CF3807@nimrod.local> Sender: netfilter-devel-owner@vger.kernel.org List-ID: On Tue, Nov 08, 2011 at 10:50:05PM +0000, Alex Bligh wrote: > --On 9 November 2011 01:16:35 +0300 Alexey Dobriyan > wrote: > > >Sorry for delay. > > > >I recall myself writing that net->nfnl NULL check is racy or > >something like that (but I can't find this email in archives). > > > >I've read the code once again, and I'm quite sure, > >NULL ->nfnl check is correct if RCU precautions are made. > > Your patch looks better than mine in this respect (as far as I > can tell from code reading rather than testing) > > >Regarding ->report check, I think it's bogus. > > All I can tell is that net->nfnl == NULL is a condition that happens > in practice. If that is read, race free, and treated as something > that causes nfnetlink_has_listeners to return 0 irrespective of > item_report, then the oops will not occur. So from my point of view > it seems right. > > Note that in the mean time I think my patch made -stable. That's news. I personally NACKed that patch. Can you confirm that, please?