[PATCH net 1/6] net/sched: sch_ingress: Only create under TC_H_INGRESS

[Peilin Ye]

ingress Qdiscs are only supposed to be created under TC_H_INGRESS.
Similar to mq_init(), return -EOPNOTSUPP if 'parent' is not
TC_H_INGRESS.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot+b53a9c0d1ea4ad62da8b@xxxxxxxxxxxxxxxxxxxxxxxxx
Link: https://lore.kernel.org/netdev/0000000000006cf87705f79acf1a@xxxxxxxxxx
Signed-off-by: Peilin Ye <peilin.ye@xxxxxxxxxxxxx>
---
 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 84838128b9c5..3d71f7a3b4ad 100644
--- a/net/sched/sch_ingress.c
+++ b/net/sched/sch_ingress.c
@@ -80,6 +80,9 @@ static int ingress_init(struct Qdisc *sch, struct nlattr *opt,
 	struct net_device *dev = qdisc_dev(sch);
 	int err;
 
+	if (sch->parent != TC_H_INGRESS)
+		return -EOPNOTSUPP;
+
 	net_inc_ingress_queue();
 
 	mini_qdisc_pair_init(&q->miniqp, sch, &dev->miniq_ingress);
-- 
2.20.1