diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c index 3d62feb65932cb8e44561fc31e092e8eaaf500ec..9d3176b080a452882d6a48168e5b84b625293de9 100644 --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -597,6 +597,7 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, 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; @@ -607,6 +608,14 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, int err; 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);