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>

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 77d3eded665ad2e30c03f8e62ea30b29ad1b4bb9..8c6563361ab538cd49cae7594d9d67bdb9b0c7e9 100644 (file)
--- 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;
 }