openvswitch: Ensure flow is valid before executing ct

The ct action uses parts of the flow key, so we need to ensure that it
is valid before executing that action.

Fixes: 7f8a436eaa2c "openvswitch: Add conntrack action"
Signed-off-by: Joe Stringer <joestringer@nicira.com>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/openvswitch/actions.c

@@ -1102,6 +1102,12 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
 			break;
 
 		case OVS_ACTION_ATTR_CT:
+			if (!is_flow_key_valid(key)) {
+				err = ovs_flow_key_update(skb, key);
+				if (err)
+					return err;
+			}
+
 			err = ovs_ct_execute(ovs_dp_get_net(dp), skb, key,
 					     nla_data(a));