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 <kennetkl@ifi.uio.no>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_fq.c b/net/sched/sch_fq.c
index 9b05924..333cd94 100644
--- a/net/sched/sch_fq.c
+++ b/net/sched/sch_fq.c
@@ -670,8 +670,14 @@
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]);