From: Eric Dumazet <edumazet@google.com>
Date: Tue, 9 Oct 2018 15:20:50 -0700
Subject: net: sched: avoid writing on noop_qdisc
Patch-mainline: v4.20-rc1
Git-commit: f98ebd47fd0da1717267ce1583a105d8cc29a16a
References: bsc#1109837
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>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
net/sched/sch_generic.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -569,6 +569,18 @@ 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);
@@ -1283,8 +1295,6 @@ static void dev_init_scheduler_queue(str
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)