net/sched: sch_ingress: Only create under TC_H_INGRESS

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

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot+b53a9c0d1ea4ad62da8b@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/r/0000000000006cf87705f79acf1a@google.com/
Tested-by: Pedro Tammela <pctammela@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Vlad Buslov <vladbu@nvidia.com>
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/sched/sch_ingress.c b/net/sched/sch_ingress.c
index 84838128b9c5b53db597c3923ca98ea5326081d7..f9ef6deb27709f246b397cd92e4a4521d7837bcf 100644 (file)
--- 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);
@@ -101,6 +104,9 @@ static void ingress_destroy(struct Qdisc *sch)
 {
        struct ingress_sched_data *q = qdisc_priv(sch);
 
+       if (sch->parent != TC_H_INGRESS)
+               return;
+
        tcf_block_put_ext(q->block, sch, &q->block_info);
        net_dec_ingress_queue();
 }