[PATCH net 2/3] net/sched: qfq: Use cl_is_active to determine whether class is active in qfq_rm_from_ag

[Jamal Hadi Salim <jhs@mojatatu.com>]

This is more of a preventive patch to make the code more consistent and
to prevent possible exploits that employ child qlen manipulations on qfq.
use cl_is_active instead of relying on the child qdisc's qlen to determine
class activation.

Fixes: 462dbc9101acd ("pkt_sched: QFQ Plus: fair-queueing service at DRR cost")
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
---
 net/sched/sch_qfq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/sched/sch_qfq.c b/net/sched/sch_qfq.c
index f4013b547438..24ea023e4990 100644
--- a/net/sched/sch_qfq.c
+++ b/net/sched/sch_qfq.c
@@ -373,7 +373,7 @@ static void qfq_rm_from_agg(struct qfq_sched *q, struct qfq_class *cl)
 /* Deschedule class and remove it from its parent aggregate. */
 static void qfq_deact_rm_from_agg(struct qfq_sched *q, struct qfq_class *cl)
 {
-	if (cl->qdisc->q.qlen > 0) /* class is active */
+	if (cl_is_active(cl)) /* class is active */
 		qfq_deactivate_class(q, cl);
 
 	qfq_rm_from_agg(q, cl);
-- 
2.34.1