static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t)
{
	struct ip_tunnel __rcu **tp;
	struct ip_tunnel *iter;

	for (tp = ipip6_bucket(sitn, t);
	     (iter = rtnl_dereference(*tp)) != NULL;
	     tp = &iter->next) {
		if (t == iter) {
			rcu_assign_pointer(*tp, t->next);
			break;
		}
	}
}

This category addresses vulnerabilities caused by flawed access control mechanisms, where incorrect permission settings allow unauthorized users to access restricted resources.