From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:33378 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730397AbeJQBOx (ORCPT ); Tue, 16 Oct 2018 21:14:53 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Cong Wang , Paolo Abeni , "David S. Miller" Subject: [PATCH 4.9 25/71] ip_tunnel: be careful when accessing the inner header Date: Tue, 16 Oct 2018 19:09:22 +0200 Message-Id: <20181016170540.656927872@linuxfoundation.org> In-Reply-To: <20181016170539.315587743@linuxfoundation.org> References: <20181016170539.315587743@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paolo Abeni [ Upstream commit ccfec9e5cb2d48df5a955b7bf47f7782157d3bc2] Cong noted that we need the same checks introduced by commit 76c0ddd8c3a6 ("ip6_tunnel: be careful when accessing the inner header") even for ipv4 tunnels. Fixes: c54419321455 ("GRE: Refactor GRE tunneling code.") Suggested-by: Cong Wang Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/ip_tunnel.c | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -627,6 +627,7 @@ void ip_tunnel_xmit(struct sk_buff *skb, const struct iphdr *tnl_params, u8 protocol) { struct ip_tunnel *tunnel = netdev_priv(dev); + unsigned int inner_nhdr_len = 0; const struct iphdr *inner_iph; struct flowi4 fl4; u8 tos, ttl; @@ -636,6 +637,14 @@ void ip_tunnel_xmit(struct sk_buff *skb, __be32 dst; bool connected; + /* ensure we can access the inner net header, for several users below */ + if (skb->protocol == htons(ETH_P_IP)) + inner_nhdr_len = sizeof(struct iphdr); + else if (skb->protocol == htons(ETH_P_IPV6)) + inner_nhdr_len = sizeof(struct ipv6hdr); + if (unlikely(!pskb_may_pull(skb, inner_nhdr_len))) + goto tx_error; + inner_iph = (const struct iphdr *)skb_inner_network_header(skb); connected = (tunnel->parms.iph.daddr != 0);