From: Xin Long <lucien.xin@gmail.com>
Date: Mon, 3 Mar 2014 12:18:36 +0000 (+0800)
Subject: ip_tunnel:multicast process cause panic due to skb->_skb_refdst NULL pointer
X-Git-Tag: v3.13.7~130
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3f1e8767921c95ff3fdea16b79540001374d9dfa;p=thirdparty%2Fkernel%2Fstable.git

ip_tunnel:multicast process cause panic due to skb->_skb_refdst NULL pointer

[ Upstream commit 10ddceb22bab11dab10ba645c7df2e4a8e7a5db5 ]

when ip_tunnel process multicast packets, it may check if the packet is looped
back packet though 'rt_is_output_route(skb_rtable(skb))' in ip_tunnel_rcv(),
but before that , skb->_skb_refdst has been dropped in iptunnel_pull_header(),
so which leads to a panic.

fix the bug: https://bugzilla.kernel.org/show_bug.cgi?id=70681

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c
index 42ffbc8d65c65..f9a146627f353 100644
--- a/net/ipv4/ip_tunnel_core.c
+++ b/net/ipv4/ip_tunnel_core.c
@@ -109,7 +109,6 @@ int iptunnel_pull_header(struct sk_buff *skb, int hdr_len, __be16 inner_proto)
 	secpath_reset(skb);
 	if (!skb->l4_rxhash)
 		skb->rxhash = 0;
-	skb_dst_drop(skb);
 	skb->vlan_tci = 0;
 	skb_set_queue_mapping(skb, 0);
 	skb->pkt_type = PACKET_HOST;