static int fib6_age(struct rt6_info *rt, void *arg)
{
	unsigned long now = jiffies;

	/*
	 *	check addrconf expiration here.
	 *	Routes are expired even if they are in use.
	 *
	 *	Also age clones. Note, that clones are aged out
	 *	only if they are not in use now.
	 */

	if (rt->rt6i_flags & RTF_EXPIRES && rt->dst.expires) {
		if (time_after(now, rt->dst.expires)) {
			RT6_TRACE("expiring %p\n", rt);
			return -1;
		}
		gc_args.more++;
	} else if (rt->rt6i_flags & RTF_CACHE) {
		if (atomic_read(&rt->dst.__refcnt) == 0 &&
		    time_after_eq(now, rt->dst.lastuse + gc_args.timeout)) {
			RT6_TRACE("aging clone %p\n", rt);
			return -1;
		} else if (rt->rt6i_flags & RTF_GATEWAY) {
			struct neighbour *neigh;
			__u8 neigh_flags = 0;

			neigh = dst_neigh_lookup(&rt->dst, &rt->rt6i_gateway);
			if (neigh) {
				neigh_flags = neigh->flags;
				neigh_release(neigh);
			}
			if (!(neigh_flags & NTF_ROUTER)) {
				RT6_TRACE("purging route %p via non-router but gateway\n",
					  rt);
				return -1;
			}
		}
		gc_args.more++;
	}

	return 0;
}

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