[PATCH 4.4 286/312] net: icmp_route_lookup should use rt dev to determine L3 domain

[Greg Kroah-Hartman]

From: David Ahern <dsa@xxxxxxxxxxxxxxxxxxx>

commit 9d1a6c4ea43e48c7880c85971c17939b56832d8a upstream.

icmp_send is called in response to some event. The skb may not have
the device set (skb->dev is NULL), but it is expected to have an rt.
Update icmp_route_lookup to use the rt on the skb to determine L3
domain.

Fixes: 613d09b30f8b ("net: Use VRF device index for lookups on TX")
Signed-off-by: David Ahern <dsa@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 net/ipv4/icmp.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -478,7 +478,7 @@ static struct rtable *icmp_route_lookup(
 	fl4->flowi4_proto = IPPROTO_ICMP;
 	fl4->fl4_icmp_type = type;
 	fl4->fl4_icmp_code = code;
-	fl4->flowi4_oif = l3mdev_master_ifindex(skb_in->dev);
+	fl4->flowi4_oif = l3mdev_master_ifindex(skb_dst(skb_in)->dev);
 
 	security_skb_classify_flow(skb_in, flowi4_to_flowi(fl4));
 	rt = __ip_route_output_key_hash(net, fl4,
@@ -503,7 +503,7 @@ static struct rtable *icmp_route_lookup(
 	if (err)
 		goto relookup_failed;
 
-	if (inet_addr_type_dev_table(net, skb_in->dev,
+	if (inet_addr_type_dev_table(net, skb_dst(skb_in)->dev,
 				     fl4_dec.saddr) == RTN_LOCAL) {
 		rt2 = __ip_route_output_key(net, &fl4_dec);
 		if (IS_ERR(rt2))