1 files changed, 101 insertions, 30 deletions

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 40b225f87d5e..4ef4bbdb49d4 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1274,18 +1274,29 @@ static DEFINE_SPINLOCK(rt6_exception_lock);
 static void rt6_remove_exception(struct rt6_exception_bucket *bucket,
 				 struct rt6_exception *rt6_ex)
 {
+	struct fib6_info *from;
 	struct net *net;
 
 	if (!bucket || !rt6_ex)
 		return;
 
 	net = dev_net(rt6_ex->rt6i->dst.dev);
+	net->ipv6.rt6_stats->fib_rt_cache--;
+
+	/* purge completely the exception to allow releasing the held resources:
+	 * some [sk] cache may keep the dst around for unlimited time
+	 */
+	from = rcu_dereference_protected(rt6_ex->rt6i->from,
+					 lockdep_is_held(&rt6_exception_lock));
+	rcu_assign_pointer(rt6_ex->rt6i->from, NULL);
+	fib6_info_release(from);
+	dst_dev_put(&rt6_ex->rt6i->dst);
+
 	hlist_del_rcu(&rt6_ex->hlist);
 	dst_release(&rt6_ex->rt6i->dst);
 	kfree_rcu(rt6_ex, rcu);
 	WARN_ON_ONCE(!bucket->depth);
 	bucket->depth--;
-	net->ipv6.rt6_stats->fib_rt_cache--;
 }
 
 /* Remove oldest rt6_ex in bucket and free the memory
@@ -1599,15 +1610,15 @@ static int rt6_remove_exception_rt(struct rt6_info *rt)
 static void rt6_update_exception_stamp_rt(struct rt6_info *rt)
 {
 	struct rt6_exception_bucket *bucket;
-	struct fib6_info *from = rt->from;
 	struct in6_addr *src_key = NULL;
 	struct rt6_exception *rt6_ex;
-
-	if (!from ||
-	    !(rt->rt6i_flags & RTF_CACHE))
-		return;
+	struct fib6_info *from;
 
 	rcu_read_lock();
+	from = rcu_dereference(rt->from);
+	if (!from || !(rt->rt6i_flags & RTF_CACHE))
+		goto unlock;
+
 	bucket = rcu_dereference(from->rt6i_exception_bucket);
 
 #ifdef CONFIG_IPV6_SUBTREES
@@ -1626,6 +1637,7 @@ static void rt6_update_exception_stamp_rt(struct rt6_info *rt)
 	if (rt6_ex)
 		rt6_ex->stamp = jiffies;
 
+unlock:
 	rcu_read_unlock();
 }
 
@@ -2277,14 +2289,8 @@ static void rt6_do_update_pmtu(struct rt6_info *rt, u32 mtu)
 
 static bool rt6_cache_allowed_for_pmtu(const struct rt6_info *rt)
 {
-	bool from_set;
-
-	rcu_read_lock();
-	from_set = !!rcu_dereference(rt->from);
-	rcu_read_unlock();
-
 	return !(rt->rt6i_flags & RTF_CACHE) &&
-		(rt->rt6i_flags & RTF_PCPU || from_set);
+		(rt->rt6i_flags & RTF_PCPU || rcu_access_pointer(rt->from));
 }
 
 static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk,
@@ -2742,20 +2748,24 @@ static int ip6_route_check_nh_onlink(struct net *net,
 	u32 tbid = l3mdev_fib_table(dev) ? : RT_TABLE_MAIN;
 	const struct in6_addr *gw_addr = &cfg->fc_gateway;
 	u32 flags = RTF_LOCAL | RTF_ANYCAST | RTF_REJECT;
+	struct fib6_info *from;
 	struct rt6_info *grt;
 	int err;
 
 	err = 0;
 	grt = ip6_nh_lookup_table(net, cfg, gw_addr, tbid, 0);
 	if (grt) {
+		rcu_read_lock();
+		from = rcu_dereference(grt->from);
 		if (!grt->dst.error &&
 		    /* ignore match if it is the default route */
-		    grt->from && !ipv6_addr_any(&grt->from->fib6_dst.addr) &&
+		    from && !ipv6_addr_any(&from->fib6_dst.addr) &&
 		    (grt->rt6i_flags & flags || dev != grt->dst.dev)) {
 			NL_SET_ERR_MSG(extack,
 				       "Nexthop has invalid gateway or device mismatch");
 			err = -EINVAL;
 		}
+		rcu_read_unlock();
 
 		ip6_rt_put(grt);
 	}
@@ -4166,6 +4176,10 @@ static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
 		cfg->fc_gateway = nla_get_in6_addr(tb[RTA_GATEWAY]);
 		cfg->fc_flags |= RTF_GATEWAY;
 	}
+	if (tb[RTA_VIA]) {
+		NL_SET_ERR_MSG(extack, "IPv6 does not support RTA_VIA attribute");
+		goto errout;
+	}
 
 	if (tb[RTA_DST]) {
 		int plen = (rtm->rtm_dst_len + 7) >> 3;
@@ -4251,17 +4265,6 @@ struct rt6_nh {
 	struct list_head next;
 };
 
-static void ip6_print_replace_route_err(struct list_head *rt6_nh_list)
-{
-	struct rt6_nh *nh;
-
-	list_for_each_entry(nh, rt6_nh_list, next) {
-		pr_warn("IPV6: multipath route replace failed (check consistency of installed routes): %pI6c nexthop %pI6c ifi %d\n",
-		        &nh->r_cfg.fc_dst, &nh->r_cfg.fc_gateway,
-		        nh->r_cfg.fc_ifindex);
-	}
-}
-
 static int ip6_route_info_append(struct net *net,
 				 struct list_head *rt6_nh_list,
 				 struct fib6_info *rt,
@@ -4407,7 +4410,8 @@ static int ip6_route_multipath_add(struct fib6_config *cfg,
 		nh->fib6_info = NULL;
 		if (err) {
 			if (replace && nhn)
-				ip6_print_replace_route_err(&rt6_nh_list);
+				NL_SET_ERR_MSG_MOD(extack,
+						   "multipath route replace failed (check consistency of installed routes)");
 			err_nh = nh;
 			goto add_errout;
 		}
@@ -4659,7 +4663,7 @@ static int rt6_fill_node(struct net *net, struct sk_buff *skb,
 		table = rt->fib6_table->tb6_id;
 	else
 		table = RT6_TABLE_UNSPEC;
-	rtm->rtm_table = table;
+	rtm->rtm_table = table < 256 ? table : RT_TABLE_COMPAT;
 	if (nla_put_u32(skb, RTA_TABLE, table))
 		goto nla_put_failure;
 
@@ -4822,6 +4826,73 @@ int rt6_dump_route(struct fib6_info *rt, void *p_arg)
 			     arg->cb->nlh->nlmsg_seq, flags);
 }
 
+static int inet6_rtm_valid_getroute_req(struct sk_buff *skb,
+					const struct nlmsghdr *nlh,
+					struct nlattr **tb,
+					struct netlink_ext_ack *extack)
+{
+	struct rtmsg *rtm;
+	int i, err;
+
+	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Invalid header for get route request");
+		return -EINVAL;
+	}
+
+	if (!netlink_strict_get_check(skb))
+		return nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX,
+				   rtm_ipv6_policy, extack);
+
+	rtm = nlmsg_data(nlh);
+	if ((rtm->rtm_src_len && rtm->rtm_src_len != 128) ||
+	    (rtm->rtm_dst_len && rtm->rtm_dst_len != 128) ||
+	    rtm->rtm_table || rtm->rtm_protocol || rtm->rtm_scope ||
+	    rtm->rtm_type) {
+		NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for get route request");
+		return -EINVAL;
+	}
+	if (rtm->rtm_flags & ~RTM_F_FIB_MATCH) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Invalid flags for get route request");
+		return -EINVAL;
+	}
+
+	err = nlmsg_parse_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
+				 rtm_ipv6_policy, extack);
+	if (err)
+		return err;
+
+	if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
+	    (tb[RTA_DST] && !rtm->rtm_dst_len)) {
+		NL_SET_ERR_MSG_MOD(extack, "rtm_src_len and rtm_dst_len must be 128 for IPv6");
+		return -EINVAL;
+	}
+
+	for (i = 0; i <= RTA_MAX; i++) {
+		if (!tb[i])
+			continue;
+
+		switch (i) {
+		case RTA_SRC:
+		case RTA_DST:
+		case RTA_IIF:
+		case RTA_OIF:
+		case RTA_MARK:
+		case RTA_UID:
+		case RTA_SPORT:
+		case RTA_DPORT:
+		case RTA_IP_PROTO:
+			break;
+		default:
+			NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in get route request");
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
 static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
 			      struct netlink_ext_ack *extack)
 {
@@ -4836,8 +4907,7 @@ static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
 	struct flowi6 fl6 = {};
 	bool fibmatch;
 
-	err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy,
-			  extack);
+	err = inet6_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
 	if (err < 0)
 		goto errout;
 
@@ -4883,7 +4953,8 @@ static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
 
 	if (tb[RTA_IP_PROTO]) {
 		err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO],
-						  &fl6.flowi6_proto, extack);
+						  &fl6.flowi6_proto, AF_INET6,
+						  extack);
 		if (err)
 			goto errout;
 	}