[{"id":1762321,"web_url":"http://patchwork.ozlabs.org/comment/1762321/","msgid":"<20170903.110436.325862367776935727.davem@davemloft.net>","list_archive_url":null,"date":"2017-09-03T18:04:36","subject":"Re: [PATCH net 0/2] l2tp: session creation fixes","submitter":{"id":15,"url":"http://patchwork.ozlabs.org/api/people/15/","name":"David Miller","email":"davem@davemloft.net"},"content":"From: Guillaume Nault \nDate: Fri, 1 Sep 2017 17:58:45 +0200\n\n> The session creation process has a few issues wrt. concurrent tunnel\n> deletion.\n> \n> Patch #1 avoids creating sessions in tunnels that are getting removed.\n> This prevents races where sessions could try to take tunnel resources\n> that were already released.\n> \n> Patch #2 removes some racy l2tp_tunnel_find() calls in session creation\n> callbacks. Together with path #1 it ensures that sessions can only\n> access tunnel resources that are guaranteed to remain valid during the\n> session creation process.\n> \n> \n> There are other problems with how sessions are created: pseudo-wire\n> specific data are set after the session is added to the tunnel. So\n> the session can be used, or deleted, before it has been completely\n> initialised. Separating session allocation from session registration\n> would be necessary, but we'd still have circular dependencies\n> preventing race-free registration. I'll consider this issue in future\n> series.\n\nSeries applied, thanks.","headers":{"Return-Path":"","X-Original-To":"patchwork-incoming@ozlabs.org","Delivered-To":"patchwork-incoming@ozlabs.org","Authentication-Results":"ozlabs.org;\n\tspf=none (mailfrom) smtp.mailfrom=vger.kernel.org\n\t(client-ip=209.132.180.67; helo=vger.kernel.org;\n\tenvelope-from=netdev-owner@vger.kernel.org;\n\treceiver=)","Received":["from vger.kernel.org (vger.kernel.org [209.132.180.67])\n\tby ozlabs.org (Postfix) with ESMTP id 3xlgqD2Gl7z9t3x\n\tfor ;\n\tMon, 4 Sep 2017 04:04:40 +1000 (AEST)","(majordomo@vger.kernel.org) by vger.kernel.org via listexpand\n\tid S1753154AbdICSEi (ORCPT );\n\tSun, 3 Sep 2017 14:04:38 -0400","from shards.monkeyblade.net ([184.105.139.130]:56498 \"EHLO\n\tshards.monkeyblade.net\" rhost-flags-OK-OK-OK-OK) by vger.kernel.org\n\twith ESMTP id S1753099AbdICSEh (ORCPT\n\t); Sun, 3 Sep 2017 14:04:37 -0400","from localhost (74-93-104-98-Washington.hfc.comcastbusiness.net\n\t[74.93.104.98]) (using TLSv1 with cipher AES256-SHA (256/256 bits))\n\t(Client did not present a certificate)\n\t(Authenticated sender: davem-davemloft)\n\tby shards.monkeyblade.net (Postfix) with ESMTPSA id 38E98120FBE82;\n\tSun, 3 Sep 2017 11:04:37 -0700 (PDT)"],"Date":"Sun, 03 Sep 2017 11:04:36 -0700 (PDT)","Message-Id":"<20170903.110436.325862367776935727.davem@davemloft.net>","To":"g.nault@alphalink.fr","Cc":"netdev@vger.kernel.org, jchapman@katalix.com","Subject":"Re: [PATCH net 0/2] l2tp: session creation fixes","From":"David Miller ","In-Reply-To":"","References":"","X-Mailer":"Mew version 6.7 on Emacs 25.2 / Mule 6.0 (HANACHIRUSATO)","Mime-Version":"1.0","Content-Type":"Text/Plain; charset=us-ascii","Content-Transfer-Encoding":"7bit","X-Greylist":"Sender succeeded SMTP AUTH, not delayed by\n\tmilter-greylist-4.5.12 (shards.monkeyblade.net\n\t[149.20.54.216]); Sun, 03 Sep 2017 11:04:37 -0700 (PDT)","Sender":"netdev-owner@vger.kernel.org","Precedence":"bulk","List-ID":"","X-Mailing-List":"netdev@vger.kernel.org"}}]