From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752780AbeE3Lwu (ORCPT ); Wed, 30 May 2018 07:52:50 -0400 Received: from mx2.suse.de ([195.135.220.15]:39609 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751817AbeE3Lwt (ORCPT ); Wed, 30 May 2018 07:52:49 -0400 Date: Wed, 30 May 2018 13:52:46 +0200 From: Michal Hocko To: "Eric W. Biederman" Cc: Andrew Morton , Johannes Weiner , Kirill Tkhai , peterz@infradead.org, viro@zeniv.linux.org.uk, mingo@kernel.org, paulmck@linux.vnet.ibm.com, keescook@chromium.org, riel@redhat.com, tglx@linutronix.de, kirill.shutemov@linux.intel.com, marcos.souza.org@gmail.com, hoeun.ryu@gmail.com, pasha.tatashin@oracle.com, gs051095@gmail.com, dhowells@redhat.com, rppt@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, Balbir Singh , Tejun Heo , Oleg Nesterov Subject: Re: [PATCH 0/2] mm->owner to mm->memcg fixes Message-ID: <20180530115246.GB20910@dhcp22.suse.cz> References: <20180504142056.GA26151@redhat.com> <87r2mrh4is.fsf@xmission.com> <20180504145435.GA26573@redhat.com> <87y3gzfmjt.fsf@xmission.com> <20180504162209.GB26573@redhat.com> <871serfk77.fsf@xmission.com> <87tvrncoyc.fsf_-_@xmission.com> <20180510121418.GD5325@dhcp22.suse.cz> <20180522125757.GL20020@dhcp22.suse.cz> <87wovu889o.fsf@xmission.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87wovu889o.fsf@xmission.com> User-Agent: Mutt/1.9.5 (2018-04-13) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 23-05-18 14:46:43, Eric W. Biederman wrote: [...] > As two processes sharing an mm is useless and highly unlikely there is > no need to handle this case well, it just needs to be handled well > enough to prevent an indefinite loop. So when css_tryget_online fails > just treat the mm as belong to the root memory cgroup. Does that mean that a malicious user can construct such a task and runaway from its limits? -- Michal Hocko SUSE Labs