[IPSEC]: Fix panic when using inter address familiy IPsec on loopback.

Signed-off-by: Kazunori MIYAZAWA <kazunori@miyazawa.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/xfrm4_mode_tunnel.c

@@ -85,6 +85,8 @@ static int xfrm4_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
 	top_iph->saddr = x->props.saddr.a4;
 	top_iph->daddr = x->id.daddr.a4;
 
+	skb->protocol = htons(ETH_P_IP);
+
 	memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options));
 	return 0;
 }