Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967567AbaFTSuu (ORCPT ); Fri, 20 Jun 2014 14:50:50 -0400 Received: from mail-pd0-f170.google.com ([209.85.192.170]:55629 "EHLO mail-pd0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966716AbaFTSus (ORCPT ); Fri, 20 Jun 2014 14:50:48 -0400 Message-ID: <53A4828D.9000200@kernel.dk> Date: Fri, 20 Jun 2014 12:50:53 -0600 From: Jens Axboe User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Vivek Goyal , Tejun Heo CC: Joe Lawrence , linux-kernel@vger.kernel.org, Cgroups Subject: Re: [PATCH block/for-linus] blkcg: fix use-after-free in __blkg_release_rcu() by making blkcg_gq refcnt an atomic_t References: <20140609174708.GA31499@redhat.com> <20140609182728.GB31499@redhat.com> <20140610143906.0d2f35d0@jlaw-desktop.mno.stratus.com> <20140611163229.GA12974@redhat.com> <20140619202640.GA9814@mtj.dyndns.org> <20140619214257.GE9814@mtj.dyndns.org> <20140620143901.GC7354@redhat.com> In-Reply-To: <20140620143901.GC7354@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/20/2014 08:39 AM, Vivek Goyal wrote: > On Thu, Jun 19, 2014 at 05:42:57PM -0400, Tejun Heo wrote: >> Hello, >> >> So, this patch should do. Joe, Vivek, can one of you guys please >> verify that the oops goes away with this patch? > > Hi Tejun, > > This patch seems to fix the issue for me. Tried 10 times and no crash. > > So now one need to hold queue lock for getting refernce on the group > only if caller does not already have a reference and if group has been > looked up from some tree/queue etc. I guess only such usage seems to > be in blkg_create() where we take a reference on parent after looking > it up. > > This patch looks good to me. > > Acked-by: Vivek Goyal Thanks. Tejun, I'll queue this up for this cycle. -- Jens Axboe -- 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/