Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753884AbcKYIkK (ORCPT ); Fri, 25 Nov 2016 03:40:10 -0500 Received: from mx2.suse.de ([195.135.220.15]:45258 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753252AbcKYIcc (ORCPT ); Fri, 25 Nov 2016 03:32:32 -0500 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Eli Cooper , "David S . Miller" , Jiri Slaby Subject: [PATCH 3.12 100/127] ip6_tunnel: Clear IP6CB in ip6tunnel_xmit() Date: Fri, 25 Nov 2016 09:30:13 +0100 Message-Id: <8881cbd16854ae23805c4798ce132d6058fe635e.1480062521.git.jslaby@suse.cz> X-Mailer: git-send-email 2.10.2 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1320 Lines: 38 From: Eli Cooper 3.12-stable review patch. If anyone has any objections, please let me know. =============== [ Upstream commit 23f4ffedb7d751c7e298732ba91ca75d224bc1a6 ] 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: Jiri Slaby --- 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 6d1549c4893c..e6f0917d1ab5 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) struct net_device_stats *stats = &dev->stats; int pkt_len, err; + memset(skb->cb, 0, sizeof(struct inet6_skb_parm)); pkt_len = skb->len; err = ip6_local_out(skb); -- 2.10.2