From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755009AbdBETfx (ORCPT + 2 others); Sun, 5 Feb 2017 14:35:53 -0500 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:28538 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754780AbdBET2x (ORCPT ); Sun, 5 Feb 2017 14:28:53 -0500 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux@roeck-us.net Cc: Eli Cooper , "David S . Miller" , Willy Tarreau Subject: [PATCH 3.10 228/319] ip6_tunnel: Clear IP6CB in ip6tunnel_xmit() Date: Sun, 5 Feb 2017 20:20:50 +0100 Message-Id: <1486322541-8206-129-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1486322541-8206-1-git-send-email-w@1wt.eu> References: <1486322541-8206-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: From: Eli Cooper commit 23f4ffedb7d751c7e298732ba91ca75d224bc1a6 upstream. skb->cb may contain data from previous layers. In the observed scenario, the garbage data were misinterpreted as IP6CB(skb)->frag_max_size, so that small packets sent through the tunnel are mistakenly fragmented. This patch unconditionally clears the control buffer in ip6tunnel_xmit(), which affects ip6_tunnel, ip6_udp_tunnel and ip6_gre. Currently none of these tunnels set IP6CB(skb)->flags, otherwise it needs to be done earlier. Cc: stable@vger.kernel.org Signed-off-by: Eli Cooper Signed-off-by: David S. Miller Signed-off-by: Willy Tarreau --- include/net/ip6_tunnel.h | 1 + 1 file changed, 1 insertion(+) diff --git a/include/net/ip6_tunnel.h b/include/net/ip6_tunnel.h index 4da5de1..b140c60 100644 --- a/include/net/ip6_tunnel.h +++ b/include/net/ip6_tunnel.h @@ -75,6 +75,7 @@ static inline void ip6tunnel_xmit(struct sk_buff *skb, struct net_device *dev) int pkt_len, err; nf_reset(skb); + memset(skb->cb, 0, sizeof(struct inet6_skb_parm)); pkt_len = skb->len; err = ip6_local_out(skb); -- 2.8.0.rc2.1.gbe9624a