pkt_sched: Fix return value corruption in HTB and TBF.

Based upon a bug report by Josip Rodin.

Packet schedulers should only return NET_XMIT_DROP iff
the packet really was dropped.  If the packet does reach
the device after we return NET_XMIT_DROP then TCP can
crash because it depends upon the enqueue path return
values being accurate.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 2 deletions

diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index 6febd245e62b..0df0df202ed0 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -577,7 +577,7 @@ static int htb_enqueue(struct sk_buff *skb, struct Qdisc *sch)
                         sch->qstats.drops++;
                         cl->qstats.drops++;
                 }
-                return NET_XMIT_DROP;
+                return ret;
         } else {
                 cl->bstats.packets +=
                         skb_is_gso(skb)?skb_shinfo(skb)->gso_segs:1;
@@ -623,7 +623,7 @@ static int htb_requeue(struct sk_buff *skb, struct Qdisc *sch)
                         sch->qstats.drops++;
                         cl->qstats.drops++;
                 }
-                return NET_XMIT_DROP;
+                return ret;
         } else
                 htb_activate(q, cl);