From 96f5a846bdd60986992228bc7dae94d4d8eaacc0 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sat, 18 May 2013 08:36:03 +0000 Subject: [PATCH] ip_gre: fix a possible crash in ipgre_err() Another fix needed in ipgre_err(), as parse_gre_header() might change skb->head. Bug added in commit c54419321455 (GRE: Refactor GRE tunneling code.) Signed-off-by: Eric Dumazet Cc: Pravin B Shelar Signed-off-by: David S. Miller --- net/ipv4/ip_gre.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index c625e4dad4b0..2a83591492dd 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -235,7 +235,7 @@ static void ipgre_err(struct sk_buff *skb, u32 info) */ struct net *net = dev_net(skb->dev); struct ip_tunnel_net *itn; - const struct iphdr *iph = (const struct iphdr *)skb->data; + const struct iphdr *iph; const int type = icmp_hdr(skb)->type; const int code = icmp_hdr(skb)->code; struct ip_tunnel *t; @@ -281,6 +281,7 @@ static void ipgre_err(struct sk_buff *skb, u32 info) else itn = net_generic(net, ipgre_net_id); + iph = (const struct iphdr *)skb->data; t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi.flags, iph->daddr, iph->saddr, tpi.key); -- 2.30.2