l2tp: fix a potential skb leak in l2tp_xmit_skb()

l2tp_xmit_skb() can leak one skb if skb_cow_head() returns an error.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index ad4ac26..34b2dde 100644 (file)
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -1045,8 +1045,10 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len
        headroom = NET_SKB_PAD + sizeof(struct iphdr) +
                uhlen + hdr_len;
        old_headroom = skb_headroom(skb);
-       if (skb_cow_head(skb, headroom))
+       if (skb_cow_head(skb, headroom)) {
+               dev_kfree_skb(skb);
                goto abort;
+       }
 
        new_headroom = skb_headroom(skb);
        skb_orphan(skb);