[PATCH AUTOSEL 4.19 194/209] net: sched: avoid writing on noop_qdisc
From: Sasha Levin <sashal@kernel.org>
Date: 2019-11-13 02:18:13
Also in:
lkml, stable
Subsystem:
networking [general], tc subsystem, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Jamal Hadi Salim, Jiri Pirko, Linus Torvalds
From: Eric Dumazet <edumazet@google.com> [ Upstream commit f98ebd47fd0da1717267ce1583a105d8cc29a16a ] While noop_qdisc.gso_skb and noop_qdisc.skb_bad_txq are not used in other places, it seems not correct to overwrite their fields in dev_init_scheduler_queue(). noop_qdisc is essentially a shared and read-only object, even if it is not marked as const because of some implementation detail. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> --- net/sched/sch_generic.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 30e32df5f84a7..8a4d01e427a22 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c@@ -577,6 +577,18 @@ struct Qdisc noop_qdisc = { .dev_queue = &noop_netdev_queue, .running = SEQCNT_ZERO(noop_qdisc.running), .busylock = __SPIN_LOCK_UNLOCKED(noop_qdisc.busylock), + .gso_skb = { + .next = (struct sk_buff *)&noop_qdisc.gso_skb, + .prev = (struct sk_buff *)&noop_qdisc.gso_skb, + .qlen = 0, + .lock = __SPIN_LOCK_UNLOCKED(noop_qdisc.gso_skb.lock), + }, + .skb_bad_txq = { + .next = (struct sk_buff *)&noop_qdisc.skb_bad_txq, + .prev = (struct sk_buff *)&noop_qdisc.skb_bad_txq, + .qlen = 0, + .lock = __SPIN_LOCK_UNLOCKED(noop_qdisc.skb_bad_txq.lock), + }, }; EXPORT_SYMBOL(noop_qdisc);
@@ -1253,8 +1265,6 @@ static void dev_init_scheduler_queue(struct net_device *dev, rcu_assign_pointer(dev_queue->qdisc, qdisc); dev_queue->qdisc_sleeping = qdisc; - __skb_queue_head_init(&qdisc->gso_skb); - __skb_queue_head_init(&qdisc->skb_bad_txq); } void dev_init_scheduler(struct net_device *dev)
--
2.20.1