Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754810Ab3EJOUx (ORCPT ); Fri, 10 May 2013 10:20:53 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:57016 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753097Ab3EJOUi (ORCPT ); Fri, 10 May 2013 10:20:38 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "David S. Miller" , "Dmitry Popov" Date: Fri, 10 May 2013 14:39:41 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [094/118] tcp: incoming connections might use wrong route under synflood In-Reply-To: X-SA-Exim-Connect-IP: 2001:470:1f08:1539:d51a:8785:aa0a:cebe X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1752 Lines: 45 3.2.45-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Dmitry Popov [ Upstream commit d66954a066158781ccf9c13c91d0316970fe57b6 ] 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 by new socket (get_cookie_sock -> tcp_v4_syn_recv_sock), so its packets may take the wrong path. Signed-off-by: Dmitry Popov Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- net/ipv4/syncookies.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/net/ipv4/syncookies.c +++ b/net/ipv4/syncookies.c @@ -347,8 +347,8 @@ struct sock *cookie_v4_check(struct sock * hasn't changed since we received the original syn, but I see * no easy way to do this. */ - flowi4_init_output(&fl4, 0, sk->sk_mark, RT_CONN_FLAGS(sk), - RT_SCOPE_UNIVERSE, IPPROTO_TCP, + flowi4_init_output(&fl4, sk->sk_bound_dev_if, 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); -- 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/