From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964896AbcFQX6U (ORCPT ); Fri, 17 Jun 2016 19:58:20 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:24622 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932901AbcFQX6R (ORCPT ); Fri, 17 Jun 2016 19:58:17 -0400 Subject: Re: kernel, mm: NULL deref in copy_process while OOMing To: Michal Hocko References: <57618763.5010201@oracle.com> <20160616093951.GD6836@dhcp22.suse.cz> Cc: "linux-mm@kvack.org" , LKML From: Sasha Levin Message-ID: <57648E92.3070703@oracle.com> Date: Fri, 17 Jun 2016 19:58:10 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <20160616093951.GD6836@dhcp22.suse.cz> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Source-IP: aserv0022.oracle.com [141.146.126.234] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/16/2016 05:39 AM, Michal Hocko wrote: > On Wed 15-06-16 12:50:43, Sasha Levin wrote: >> Hi all, >> >> I'm seeing the following NULL ptr deref in copy_process right after a bunch >> of OOM killing activity on -next kernels: >> >> Out of memory (oom_kill_allocating_task): Kill process 3477 (trinity-c159) score 0 or sacrifice child >> Killed process 3477 (trinity-c159) total-vm:3226820kB, anon-rss:36832kB, file-rss:1640kB, shmem-rss:444kB >> oom_reaper: reaped process 3477 (trinity-c159), now anon-rss:0kB, file-rss:0kB, shmem-rss:444kB >> Out of memory (oom_kill_allocating_task): Kill process 3450 (trinity-c156) score 0 or sacrifice child >> Killed process 3450 (trinity-c156) total-vm:3769768kB, anon-rss:36832kB, file-rss:1652kB, shmem-rss:508kB >> oom_reaper: reaped process 3450 (trinity-c156), now anon-rss:0kB, file-rss:0kB, shmem-rss:572kB >> BUG: unable to handle kernel NULL pointer dereference at 0000000000000150 >> IP: copy_process (./arch/x86/include/asm/atomic.h:103 kernel/fork.c:484 kernel/fork.c:964 kernel/fork.c:1018 kernel/fork.c:1484) >> PGD 1ff944067 PUD 1ff929067 PMD 0 >> Oops: 0002 [#1] PREEMPT SMP KASAN >> Modules linked in: >> CPU: 18 PID: 8761 Comm: trinity-main Not tainted 4.7.0-rc3-sasha-02101-g1e1b9fa #3108 > > Is this a common parent of the oom killed children? Yup, it's trying to spawn new ones while existing children are getting killed. Thanks, Sasha