Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756247AbaBEVC2 (ORCPT ); Wed, 5 Feb 2014 16:02:28 -0500 Received: from mail1.windriver.com ([147.11.146.13]:48083 "EHLO mail1.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754387AbaBEUFL (ORCPT ); Wed, 5 Feb 2014 15:05:11 -0500 From: Paul Gortmaker To: , CC: Eric Dumazet , "David S. Miller" , Paul Gortmaker Subject: [v2.6.34-stable 062/213] tcp: drop SYN+FIN messages Date: Wed, 5 Feb 2014 15:00:17 -0500 Message-ID: <1391630568-49251-63-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.8.5.2 In-Reply-To: <1391630568-49251-1-git-send-email-paul.gortmaker@windriver.com> References: <1391630568-49251-1-git-send-email-paul.gortmaker@windriver.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Dumazet ------------------- This is a commit scheduled for the next v2.6.34 longterm release. http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git If you see a problem with using this for longterm, please comment. ------------------- commit fdf5af0daf8019cec2396cdef8fb042d80fe71fa upstream. Denys Fedoryshchenko reported that SYN+FIN attacks were bringing his linux machines to their limits. Dont call conn_request() if the TCP flags includes SYN flag Reported-by: Denys Fedoryshchenko Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Paul Gortmaker --- net/ipv4/tcp_input.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index df5de7dd22d2..20af12ae55a7 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5737,6 +5737,8 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb, goto discard; if (th->syn) { + if (th->fin) + goto discard; if (icsk->icsk_af_ops->conn_request(sk, skb) < 0) return 1; -- 1.8.5.2 -- 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/