From 3725a269815ba6dbb415feddc47da5af7d1fac58 Mon Sep 17 00:00:00 2001 From: Kenneth Klette Jonassen Date: Tue, 3 Feb 2015 17:49:18 +0100 Subject: [PATCH] pkt_sched: fq: avoid hang when quantum 0 Configuring fq with quantum 0 hangs the system, presumably because of a non-interruptible infinite loop. Either way quantum 0 does not make sense. Reproduce with: sudo tc qdisc add dev lo root fq quantum 0 initial_quantum 0 ping 127.0.0.1 Signed-off-by: Kenneth Klette Jonassen Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- net/sched/sch_fq.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/net/sched/sch_fq.c b/net/sched/sch_fq.c index 9b05924cc386..333cd94ba381 100644 --- a/net/sched/sch_fq.c +++ b/net/sched/sch_fq.c @@ -670,8 +670,14 @@ static int fq_change(struct Qdisc *sch, struct nlattr *opt) if (tb[TCA_FQ_FLOW_PLIMIT]) q->flow_plimit = nla_get_u32(tb[TCA_FQ_FLOW_PLIMIT]); - if (tb[TCA_FQ_QUANTUM]) - q->quantum = nla_get_u32(tb[TCA_FQ_QUANTUM]); + if (tb[TCA_FQ_QUANTUM]) { + u32 quantum = nla_get_u32(tb[TCA_FQ_QUANTUM]); + + if (quantum > 0) + q->quantum = quantum; + else + err = -EINVAL; + } if (tb[TCA_FQ_INITIAL_QUANTUM]) q->initial_quantum = nla_get_u32(tb[TCA_FQ_INITIAL_QUANTUM]); -- GitLab