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authorPeilin Ye <peilin.ye@bytedance.com>2023-05-29 12:54:26 -0700
committerJakub Kicinski <kuba@kernel.org>2023-05-30 23:31:05 -0700
commit9de95df5d15baa956c2b70b9e794842e790a8a13 (patch)
treebe5956f7c395c9783e9b70ebb7666b67d9517c4d /net/sched
parentf85fa45d4a9408d98c46c8fa45ba2e3b2f4bf219 (diff)
net/sched: Prohibit regrafting ingress or clsact Qdiscs
Currently, after creating an ingress (or clsact) Qdisc and grafting it under TC_H_INGRESS (TC_H_CLSACT), it is possible to graft it again under e.g. a TBF Qdisc: $ ip link add ifb0 type ifb $ tc qdisc add dev ifb0 handle 1: root tbf rate 20kbit buffer 1600 limit 3000 $ tc qdisc add dev ifb0 clsact $ tc qdisc link dev ifb0 handle ffff: parent 1:1 $ tc qdisc show dev ifb0 qdisc tbf 1: root refcnt 2 rate 20Kbit burst 1600b lat 560.0ms qdisc clsact ffff: parent ffff:fff1 refcnt 2 ^^^^^^^^ clsact's refcount has increased: it is now grafted under both TC_H_CLSACT and 1:1. ingress and clsact Qdiscs should only be used under TC_H_INGRESS (TC_H_CLSACT). Prohibit regrafting them. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Fixes: 1f211a1b929c ("net, sched: add clsact qdisc") 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>
Diffstat (limited to 'net/sched')
-rw-r--r--net/sched/sch_api.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 383195955b7d..49b9c1bbfdd9 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -1596,6 +1596,11 @@ replay:
NL_SET_ERR_MSG(extack, "Invalid qdisc name");
return -EINVAL;
}
+ if (q->flags & TCQ_F_INGRESS) {
+ NL_SET_ERR_MSG(extack,
+ "Cannot regraft ingress or clsact Qdiscs");
+ return -EINVAL;
+ }
if (q == p ||
(p && check_loop(q, p, 0))) {
NL_SET_ERR_MSG(extack, "Qdisc parent/child loop detected");