Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932213Ab0BDNSa (ORCPT ); Thu, 4 Feb 2010 08:18:30 -0500 Received: from dallas.jonmasters.org ([72.29.103.172]:45805 "EHLO dallas.jonmasters.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756472Ab0BDNS2 (ORCPT ); Thu, 4 Feb 2010 08:18:28 -0500 Subject: Re: [PATCH] netfilter: per netns nf_conntrack_cachep From: Jon Masters To: Patrick McHardy Cc: Alexey Dobriyan , Eric Dumazet , linux-kernel , netdev , netfilter-devel , "Paul E. McKenney" In-Reply-To: <4B6AC5DC.60301@trash.net> References: <1265108690.2861.118.camel@tonnant> <1265134598.2861.191.camel@tonnant> <4B6870AF.6060109@trash.net> <4B6967BC.600@trash.net> <1265222289.2861.290.camel@tonnant> <20100203190948.GA5182@x200> <1265226227.2861.302.camel@tonnant> <4B6ABCB8.4080904@trash.net> <4B6ABDEF.8090005@trash.net> <4B6AC5DC.60301@trash.net> Content-Type: text/plain Organization: World Organi[sz]ation of Broken Dreams Date: Thu, 04 Feb 2010 08:18:06 -0500 Message-Id: <1265289486.2861.436.camel@tonnant> Mime-Version: 1.0 X-Mailer: Evolution 2.26.3 (2.26.3-1.fc11) Content-Transfer-Encoding: 7bit X-SA-Do-Not-Run: Yes X-SA-Exim-Connect-IP: 127.0.0.1 X-SA-Exim-Mail-From: jonathan@jonmasters.org X-SA-Exim-Scanned: No (on dallas.jonmasters.org); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2120 Lines: 48 On Thu, 2010-02-04 at 14:04 +0100, Patrick McHardy wrote: > Alexey Dobriyan wrote: > > On Thu, Feb 4, 2010 at 2:30 PM, Patrick McHardy wrote: > >> Alexey Dobriyan wrote: > >>> On Thu, Feb 4, 2010 at 2:25 PM, Patrick McHardy wrote: > >>>> Jon Masters wrote: > >>>>> On Wed, 2010-02-03 at 21:09 +0200, Alexey Dobriyan wrote: > >>>>>> On Wed, Feb 03, 2010 at 01:38:09PM -0500, Jon Masters wrote: > >>>>>>> *). Per namespace cacheing allocation (the cachep bits). We know it's > >>>>>>> still possible for weirdness to happen in the SLAB cache here. > >>>>>> Tiny race, needs reproducer. > >>>>> Maybe. I think it's worth fixing anyway. > >>>> Absolutely, I'll also apply Eric's patch with the %p fix for the > >>>> slab name. > >>> This would show kernel pointers in userspace ;-) > >>> So, net->id is required. > >> I don't see the problem. But yes, it would be nicer to have an ID. > > > > This is done (or rather, not done) to not show attackers > > where data structures are. > > That's news to me, my /proc is full of kernel space pointers, > including data. And anyway, you can guess it in many cases. I don't think there's a huge problem, but you could of course just stash a global atomic somewhere to keep track of how many of these you've made if that's easier for now. > In any case, we need a fix for this suitable for 2.6.33. If > you don't like using the pointer, please send a patch to add > an id to the network namespaces. Right. I think the quick solution is fine for 2.6.33. So that makes the hashtable non-resize patch, the crash fix, and the cachep bits. I will try to get involved and help you out with the per-ns hashtable clean rather than just being a whiner :) Thanks a bunch! Fedora kernels have already been built with this fix, since it will allow us to close a fair number of "KVM goes boom" bugs. Jon. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/