ipv4: use dst with ref during bcast/mcast loopback

Make sure skb dst has reference when moving to
another context. Currently, I don't see protocols that can
hit it when sending broadcasts/multicasts to loopback using
noref dsts, so it is just a precaution.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 0 deletions

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 77d3eded665a..8c6563361ab5 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -122,6 +122,7 @@ static int ip_dev_loopback_xmit(struct sk_buff *newskb)
         newskb->pkt_type = PACKET_LOOPBACK;
         newskb->ip_summed = CHECKSUM_UNNECESSARY;
         WARN_ON(!skb_dst(newskb));
+        skb_dst_force(newskb);
         netif_rx_ni(newskb);
         return 0;
 }