[ 23/72] net_sched: Bug in netem reordering

From: Greg KH
Date: Mon Feb 27 2012 - 20:17:39 EST


3.2-stable review patch. If anyone has any objections, please let me know.

------------------


From: Hagen Paul Pfeifer <hagen@xxxxxxxx>

[ Upstream commit eb10192447370f19a215a8c2749332afa1199d46 ]

Not now, but it looks you are correct. q->qdisc is NULL until another
additional qdisc is attached (beside tfifo). See 50612537e9ab2969312.
The following patch should work.

From: Hagen Paul Pfeifer <hagen@xxxxxxxx>

netem: catch NULL pointer by updating the real qdisc statistic

Reported-by: Vijay Subramanian <subramanian.vijay@xxxxxxxxx>
Signed-off-by: Hagen Paul Pfeifer <hagen@xxxxxxxx>
Acked-by: Eric Dumazet <eric.dumazet@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/sched/sch_netem.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -383,8 +383,8 @@ static int netem_enqueue(struct sk_buff
q->counter = 0;

__skb_queue_head(&q->qdisc->q, skb);
- q->qdisc->qstats.backlog += qdisc_pkt_len(skb);
- q->qdisc->qstats.requeues++;
+ sch->qstats.backlog += qdisc_pkt_len(skb);
+ sch->qstats.requeues++;
ret = NET_XMIT_SUCCESS;
}



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/