From e96f2e7c430014eff52c93cabef1ad4f42ed0db1 Mon Sep 17 00:00:00 2001 From: Ying Cai Date: Sun, 4 May 2014 15:20:04 -0700 Subject: [PATCH] ip_tunnel: Set network header properly for IP_ECN_decapsulate() In ip_tunnel_rcv(), set skb->network_header to inner IP header before IP_ECN_decapsulate(). Without the fix, IP_ECN_decapsulate() takes outer IP header as inner IP header, possibly causing error messages or packet drops. Note that this skb_reset_network_header() call was in this spot when the original feature for checking consistency of ECN bits through tunnels was added in eccc1bb8d4b4 ("tunnel: drop packet if ECN present with not-ECT"). It was only removed from this spot in 3d7b46cd20e3 ("ip_tunnel: push generic protocol handling to ip_tunnel module."). Fixes: 3d7b46cd20e3 ("ip_tunnel: push generic protocol handling to ip_tunnel module.") Reported-by: Neal Cardwell Signed-off-by: Ying Cai Acked-by: Neal Cardwell Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/ip_tunnel.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c index fa5b7519765f..b3f859731c60 100644 --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -442,6 +442,8 @@ int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb, tunnel->i_seqno = ntohl(tpi->seq) + 1; } + skb_reset_network_header(skb); + err = IP_ECN_decapsulate(iph, skb); if (unlikely(err)) { if (log_ecn_error)