Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935533Ab3DKD0P (ORCPT ); Wed, 10 Apr 2013 23:26:15 -0400 Received: from shards.monkeyblade.net ([149.20.54.216]:55830 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761908Ab3DKD0O (ORCPT ); Wed, 10 Apr 2013 23:26:14 -0400 Date: Wed, 10 Apr 2013 23:26:12 -0400 (EDT) Message-Id: <20130410.232612.1922869742696275542.davem@davemloft.net> To: dp@highloadlab.com Cc: kuznet@ms2.inr.ac.ru, jmorris@namei.org, yoshfuji@linux-ipv6.org, kaber@trash.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] tcp: incoming connections might use wrong route under synflood From: David Miller In-Reply-To: <20130411000909.d90c6df468bf1830174e88e2@highloadlab.com> References: <20130411000909.d90c6df468bf1830174e88e2@highloadlab.com> X-Mailer: Mew version 6.5 on Emacs 24.1 / 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 milter-greylist-4.2.7 (shards.monkeyblade.net [0.0.0.0]); Wed, 10 Apr 2013 20:26:14 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1078 Lines: 23 From: Dmitry Popov Date: Thu, 11 Apr 2013 00:09:09 +0400 > There is a bug in cookie_v4_check (net/ipv4/syncookies.c): > flowi4_init_output(&fl4, 0, sk->sk_mark, RT_CONN_FLAGS(sk), > RT_SCOPE_UNIVERSE, IPPROTO_TCP, > inet_sk_flowi_flags(sk), > (opt && opt->srr) ? opt->faddr : ireq->rmt_addr, > ireq->loc_addr, th->source, th->dest); > > Here we do not respect sk->sk_bound_dev_if, therefore wrong dst_entry may be taken. This dst_entry is used in new socket (get_cookie_sock -> tcp_v4_syn_recv_sock), so its packets may take wrong path. There is no such bug in ipv6 code and non-cookie code (usual case). Bugfix below. > > Signed-off-by: Dmitry Popov Please format your commit messages properly, by not allowing lines of text longer than 80 columns. Thank you. -- 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/