pkt_sched: sch_generic: Fix oops in sch_teql

After these commands:
# modprobe sch_teql
# tc qdisc add dev eth0 root teql0
# tc qdisc del dev eth0 root
we get an oops in teql_destroy() when spin_lock is taken from a null
qdisc_sleeping pointer. It's because at the moment teql0 dev haven't
been activated yet, and a qdisc_root_sleeping() is pointing to noop
qdisc's netdev_queue with qdisc_sleeping uninitialized. This patch
fixes this both for noop and noqueue netdev_queues to avoid similar
problems in the future.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 0 deletions

diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 7b5572d6beb5..93cd30ce6501 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -326,6 +326,7 @@ struct Qdisc_ops noop_qdisc_ops __read_mostly = {
 
 static struct netdev_queue noop_netdev_queue = {
         .qdisc          =       &noop_qdisc,
+        .qdisc_sleeping =       &noop_qdisc,
 };
 
 struct Qdisc noop_qdisc = {
@@ -352,6 +353,7 @@ static struct Qdisc_ops noqueue_qdisc_ops __read_mostly = {
 static struct Qdisc noqueue_qdisc;
 static struct netdev_queue noqueue_netdev_queue = {
         .qdisc          =       &noqueue_qdisc,
+        .qdisc_sleeping =       &noqueue_qdisc,
 };
 
 static struct Qdisc noqueue_qdisc = {