From 69747650c814a8a79fef412c7416adf823293a3e Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Sun, 17 Aug 2008 23:55:36 -0700 Subject: [PATCH] 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 --- net/sched/sch_htb.c | 4 ++-- net/sched/sch_tbf.c | 11 ++--------- 2 files changed, 4 insertions(+), 11 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); diff --git a/net/sched/sch_tbf.c b/net/sched/sch_tbf.c index 7d3b7ff3bf07..94c61598b86a 100644 --- a/net/sched/sch_tbf.c +++ b/net/sched/sch_tbf.c @@ -123,15 +123,8 @@ static int tbf_enqueue(struct sk_buff *skb, struct Qdisc* sch) struct tbf_sched_data *q = qdisc_priv(sch); int ret; - if (qdisc_pkt_len(skb) > q->max_size) { - sch->qstats.drops++; -#ifdef CONFIG_NET_CLS_ACT - if (sch->reshape_fail == NULL || sch->reshape_fail(skb, sch)) -#endif - kfree_skb(skb); - - return NET_XMIT_DROP; - } + if (qdisc_pkt_len(skb) > q->max_size) + return qdisc_reshape_fail(skb, sch); ret = qdisc_enqueue(skb, q->qdisc); if (ret != 0) { -- 2.20.1