ip6erspan: make sure enough headroom at xmit.

The patch adds skb_cow_header() to ensure enough headroom
at ip6erspan_tunnel_xmit before pushing the erspan header
to the skb.

Signed-off-by: William Tu <u9012063@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index a299f5424e166cde51d553cac98f92493ceb3faa..1bbd0930063eeca7a75aab193a53fdae5f9e973b 100644 (file)
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -903,6 +903,9 @@ static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
                truncate = true;
        }
 
+       if (skb_cow_head(skb, dev->needed_headroom))
+               goto tx_err;
+
        t->parms.o_flags &= ~TUNNEL_KEY;
        IPCB(skb)->flags = 0;