clsact Qdiscs are only supposed to be created under TC_H_CLSACT (which
equals TC_H_INGRESS).  Return -EOPNOTSUPP if 'parent' is not
TC_H_CLSACT.

Fixes: 1f211a1b929c ("net, sched: add clsact qdisc")
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
---
 net/sched/sch_ingress.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/sched/sch_ingress.c b/net/sched/sch_ingress.c
index 3d71f7a3b4ad..13218a1fe4a5 100644
--- a/net/sched/sch_ingress.c
+++ b/net/sched/sch_ingress.c
@@ -222,6 +222,9 @@ static int clsact_init(struct Qdisc *sch, struct nlattr *opt,
 	struct net_device *dev = qdisc_dev(sch);
 	int err;
 
+	if (sch->parent != TC_H_CLSACT)
+		return -EOPNOTSUPP;
+
 	net_inc_ingress_queue();
 	net_inc_egress_queue();
 
-- 
2.20.1