netem: fix possible skb leak

[ Upstream commit 116a0fc31c6c9b8fc821be5a96e5bf0b43260131 ]

skb_checksum_help(skb) can return an error, we must free skb in this
case. qdisc_drop(skb, sch) can also be feeded with a NULL skb (if
skb_unshare() failed), so lets use this generic helper.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index 7801b15b56884f71cbf0ce1bfecf89340018944d..a489d8bcfd410d21053d4ca402cb73722b0b604c 100644 (file)
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -351,10 +351,8 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch)
        if (q->corrupt && q->corrupt >= get_crandom(&q->corrupt_cor)) {
                if (!(skb = skb_unshare(skb, GFP_ATOMIC)) ||
                    (skb->ip_summed == CHECKSUM_PARTIAL &&
-                    skb_checksum_help(skb))) {
-                       sch->qstats.drops++;
-                       return NET_XMIT_DROP;
-               }
+                    skb_checksum_help(skb)))
+                       return qdisc_drop(skb, sch);
 
                skb->data[net_random() % skb_headlen(skb)] ^= 1<<(net_random() % 8);
        }