Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262392AbVE0J0n (ORCPT ); Fri, 27 May 2005 05:26:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262408AbVE0JYY (ORCPT ); Fri, 27 May 2005 05:24:24 -0400 Received: from ecfrec.frec.bull.fr ([129.183.4.8]:39057 "EHLO ecfrec.frec.bull.fr") by vger.kernel.org with ESMTP id S262406AbVE0JJX (ORCPT ); Fri, 27 May 2005 05:09:23 -0400 Date: Fri, 27 May 2005 11:09:02 +0200 (CEST) From: Simon Derr X-X-Sender: derrs@openx3.frec.bull.fr To: Paul Jackson Cc: Andrew Morton , Dinakar Guniguntala , Linus Torvalds , Simon Derr , linux-kernel@vger.kernel.org Subject: Re: [PATCH 2.6.12-rc4: resent] cpuset exit NULL dereference fix In-Reply-To: <20050527090243.30833.93829.sendpatchset@tomahawk.engr.sgi.com> Message-ID: References: <20050527090243.30833.93829.sendpatchset@tomahawk.engr.sgi.com> MIME-Version: 1.0 X-MIMETrack: Itemize by SMTP Server on ECN002/FR/BULL(Release 5.0.12 |February 13, 2003) at 27/05/2005 11:20:01, Serialize by Router on ECN002/FR/BULL(Release 5.0.12 |February 13, 2003) at 27/05/2005 11:20:04, Serialize complete at 27/05/2005 11:20:04 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1470 Lines: 39 On Fri, 27 May 2005, Paul Jackson wrote: > Andrew, > > Resubmitting the same patch I submitted yesterday. Simon Derr > and I agree that we need this patch now to fix a kernel crash. > > The potential scaling issues are theoretical at this time. > When they become more real, we will be in a better position to > consider more ambitious changes to cpuset locking and reference > counting. > > Meanwhile -- this patch is small, simple, and needed. > > === > > There is a race in the kernel cpuset code, between the code > to handle notify_on_release, and the code to remove a cpuset. > The notify_on_release code can end up trying to access a > cpuset that has been removed. In the most common case, this > causes a NULL pointer dereference from the routine cpuset_path. > However all manner of bad things are possible, in theory at least. > Signed-off-by: Paul Jackson > > Index: 2.6-cpuset_path_fix/kernel/cpuset.c > =================================================================== > --- 2.6-cpuset_path_fix.orig/kernel/cpuset.c 2005-05-25 19:20:27.000000000 -0700 > +++ 2.6-cpuset_path_fix/kernel/cpuset.c 2005-05-26 00:50:32.000000000 -0700 OK for me. Acked-by: Simon Derr - 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/