From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964841Ab2JAXTP (ORCPT ); Mon, 1 Oct 2012 19:19:15 -0400 Received: from 1wt.eu ([62.212.114.60]:35423 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932941Ab2JAXBo (ORCPT ); Mon, 1 Oct 2012 19:01:44 -0400 Message-Id: <20121001225203.630763715@1wt.eu> User-Agent: quilt/0.48-1 Date: Tue, 02 Oct 2012 00:54:19 +0200 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Eric Dumazet , "David S. Miller" , Ben Hutchings , Greg Kroah-Hartman , Willy Tarreau Subject: [ 142/180] tcp: drop SYN+FIN messages In-Reply-To: <6a854f579a99b4fe2efaca1057e8ae22@local> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet 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 Cc: Ben Hutchings Signed-off-by: Greg Kroah-Hartman Signed-off-by: Willy Tarreau --- net/ipv4/tcp_input.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 4b148e5..db755c4 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5634,6 +5634,8 @@ 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; -- 1.7.2.1.45.g54fbc