Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753004AbcKSJVG (ORCPT ); Sat, 19 Nov 2016 04:21:06 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:57860 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752931AbcKSJVC (ORCPT ); Sat, 19 Nov 2016 04:21:02 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eli Cooper , "David S. Miller" Subject: [PATCH 4.4 05/37] ip6_tunnel: Clear IP6CB in ip6tunnel_xmit() Date: Sat, 19 Nov 2016 10:20:21 +0100 Message-Id: <20161119092010.299702612@linuxfoundation.org> X-Mailer: git-send-email 2.10.2 In-Reply-To: <20161119092010.016555184@linuxfoundation.org> References: <20161119092010.016555184@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1257 Lines: 36 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eli Cooper [ 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: Greg Kroah-Hartman --- include/net/ip6_tunnel.h | 1 + 1 file changed, 1 insertion(+) --- a/include/net/ip6_tunnel.h +++ b/include/net/ip6_tunnel.h @@ -86,6 +86,7 @@ static inline void ip6tunnel_xmit(struct struct net_device_stats *stats = &dev->stats; int pkt_len, err; + memset(skb->cb, 0, sizeof(struct inet6_skb_parm)); pkt_len = skb->len - skb_inner_network_offset(skb); err = ip6_local_out(dev_net(skb_dst(skb)->dev), sk, skb);