ife: error out when nla attributes are empty

act_ife at least requires TCA_IFE_PARMS, so we have to bail out
when there is no attribute passed in.

Reported-by: [email protected]
Fixes: ef6980b ("introduce IFE action")
Cc: Jamal Hadi Salim <[email protected]>
Cc: Jiri Pirko <[email protected]>
Signed-off-by: Cong Wang <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: congwang

net/sched/act_ife.c

@@ -481,6 +481,11 @@ static int tcf_ife_init(struct net *net, struct nlattr *nla,
 	int ret = 0;
 	int err;
 
+	if (!nla) {
+		NL_SET_ERR_MSG_MOD(extack, "IFE requires attributes to be passed");
+		return -EINVAL;
+	}
+
 	err = nla_parse_nested_deprecated(tb, TCA_IFE_MAX, nla, ife_policy,
 					  NULL);
 	if (err < 0)