Commit 80b20d52 authored May 29, 2023 by Peilin Ye Committed by Greg Kroah-Hartman Jun 09, 2023

net/sched: Reserve TC_H_INGRESS (TC_H_CLSACT) for ingress (clsact) Qdiscs



[ Upstream commit f85fa45d4a9408d98c46c8fa45ba2e3b2f4bf219 ]

Currently it is possible to add e.g. an HTB Qdisc under ffff:fff1
(TC_H_INGRESS, TC_H_CLSACT):

  $ ip link add name ifb0 type ifb
  $ tc qdisc add dev ifb0 parent ffff:fff1 htb
  $ tc qdisc add dev ifb0 clsact
  Error: Exclusivity flag on, cannot modify.
  $ drgn
  ...
  >>> ifb0 = netdev_get_by_name(prog, "ifb0")
  >>> qdisc = ifb0.ingress_queue.qdisc_sleeping
  >>> print(qdisc.ops.id.string_().decode())
  htb
  >>> qdisc.flags.value_() # TCQ_F_INGRESS
  2

Only allow ingress and clsact Qdiscs under ffff:fff1.  Return -EINVAL
for everything else.  Make TCQ_F_INGRESS a static flag of ingress and
clsact Qdiscs.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Fixes: 1f211a1b ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 321f3837

net/sched/sch_api.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -1214,7 +1214,12 @@ static struct Qdisc qdisc_create(struct net_device dev,
		sch->parent = parent;

		if (handle == TC_H_INGRESS) {
		sch->flags \|= TCQ_F_INGRESS;
		if (!(sch->flags & TCQ_F_INGRESS)) {
		NL_SET_ERR_MSG(extack,
		"Specified parent ID is reserved for ingress and clsact Qdiscs");
		err = -EINVAL;
		goto err_out3;
		}
		handle = TC_H_MAKE(TC_H_INGRESS, 0);
		} else {
		if (handle == 0) {

net/sched/sch_ingress.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -133,7 +133,7 @@ static struct Qdisc_ops ingress_qdisc_ops __read_mostly = {
		.cl_ops = &ingress_class_ops,
		.id = "ingress",
		.priv_size = sizeof(struct ingress_sched_data),
		.static_flags = TCQ_F_CPUSTATS,
		.static_flags = TCQ_F_INGRESS \| TCQ_F_CPUSTATS,
		.init = ingress_init,
		.destroy = ingress_destroy,
		.dump = ingress_dump,
		@@ -272,7 +272,7 @@ static struct Qdisc_ops clsact_qdisc_ops __read_mostly = {
		.cl_ops = &clsact_class_ops,
		.id = "clsact",
		.priv_size = sizeof(struct clsact_sched_data),
		.static_flags = TCQ_F_CPUSTATS,
		.static_flags = TCQ_F_INGRESS \| TCQ_F_CPUSTATS,
		.init = clsact_init,
		.destroy = clsact_destroy,
		.dump = ingress_dump,