net: fib_rules: Add error_free label in fib_delrule().

We will hold RTNL just before calling fib_nl2rule_rtnl() in
fib_delrule() and release it before kfree(nlrule).

Let's add a new rule to make the following change cleaner.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20250207072502.87775-8-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: q2ven

net/core/fib_rules.c

@@ -946,23 +946,23 @@ int fib_delrule(struct net *net, struct sk_buff *skb, struct nlmsghdr *nlh,
 
 	err = fib_nl2rule_rtnl(nlrule, ops, tb, extack);
 	if (err)
-		goto errout;
+		goto errout_free;
 
 	rule = rule_find(ops, frh, tb, nlrule, user_priority);
 	if (!rule) {
 		err = -ENOENT;
-		goto errout;
+		goto errout_free;
 	}
 
 	if (rule->flags & FIB_RULE_PERMANENT) {
 		err = -EPERM;
-		goto errout;
+		goto errout_free;
 	}
 
 	if (ops->delete) {
 		err = ops->delete(rule);
 		if (err)
-			goto errout;
+			goto errout_free;
 	}
 
 	if (rule->tun_id)
@@ -1008,8 +1008,9 @@ int fib_delrule(struct net *net, struct sk_buff *skb, struct nlmsghdr *nlh,
 	kfree(nlrule);
 	return 0;
 
-errout:
+errout_free:
 	kfree(nlrule);
+errout:
 	rules_ops_put(ops);
 	return err;
 }