1 files changed, 38 insertions, 5 deletions

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 738ff0a1a048..6fdf1c195d8e 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1183,11 +1183,39 @@ static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
 	return dst;
 }
 
+static void ipv4_send_dest_unreach(struct sk_buff *skb)
+{
+	struct ip_options opt;
+	int res;
+
+	/* Recompile ip options since IPCB may not be valid anymore.
+	 * Also check we have a reasonable ipv4 header.
+	 */
+	if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) ||
+	    ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5)
+		return;
+
+	memset(&opt, 0, sizeof(opt));
+	if (ip_hdr(skb)->ihl > 5) {
+		if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4))
+			return;
+		opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr);
+
+		rcu_read_lock();
+		res = __ip_options_compile(dev_net(skb->dev), &opt, skb, NULL);
+		rcu_read_unlock();
+
+		if (res)
+			return;
+	}
+	__icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &opt);
+}
+
 static void ipv4_link_failure(struct sk_buff *skb)
 {
 	struct rtable *rt;
 
-	icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
+	ipv4_send_dest_unreach(skb);
 
 	rt = skb_rtable(skb);
 	if (rt)
@@ -1303,6 +1331,10 @@ static void ip_del_fnhe(struct fib_nh *nh, __be32 daddr)
 		if (fnhe->fnhe_daddr == daddr) {
 			rcu_assign_pointer(*fnhe_p, rcu_dereference_protected(
 				fnhe->fnhe_next, lockdep_is_held(&fnhe_lock)));
+			/* set fnhe_daddr to 0 to ensure it won't bind with
+			 * new dsts in rt_bind_exception().
+			 */
+			fnhe->fnhe_daddr = 0;
 			fnhe_flush_routes(fnhe);
 			kfree_rcu(fnhe, rcu);
 			break;
@@ -2149,12 +2181,13 @@ int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 		int our = 0;
 		int err = -EINVAL;
 
-		if (in_dev)
-			our = ip_check_mc_rcu(in_dev, daddr, saddr,
-					      ip_hdr(skb)->protocol);
+		if (!in_dev)
+			return err;
+		our = ip_check_mc_rcu(in_dev, daddr, saddr,
+				      ip_hdr(skb)->protocol);
 
 		/* check l3 master if no match yet */
-		if ((!in_dev || !our) && netif_is_l3_slave(dev)) {
+		if (!our && netif_is_l3_slave(dev)) {
 			struct in_device *l3_in_dev;
 
 			l3_in_dev = __in_dev_get_rcu(skb->dev);