datapath: compat: Add NULL check for tun-dst.

tun-dst could be NULL in case of incorrect action list
where set tunnel action is missing but packet is sent
to tunnel vport.

Signed-off-by: Pravin B Shelar <pshelar@ovn.org>
Acked-by: Joe Stringer <joe@ovn.org>

diff --git a/datapath/linux/compat/gso.h b/datapath/linux/compat/gso.h
index eb756eb..0f2b09a 100644 (file)
--- a/datapath/linux/compat/gso.h
+++ b/datapath/linux/compat/gso.h
@@ -170,7 +170,10 @@ static inline void ovs_skb_dst_set(struct sk_buff *skb, void *dst)
 
 static inline struct ip_tunnel_info *ovs_skb_tunnel_info(struct sk_buff *skb)
 {
-       return &OVS_GSO_CB(skb)->tun_dst->u.tun_info;
+       if (likely(OVS_GSO_CB(skb)->tun_dst))
+               return &OVS_GSO_CB(skb)->tun_dst->u.tun_info;
+       else
+               return NULL;
 }
 
 static inline void ovs_skb_dst_drop(struct sk_buff *skb)