[PKT_SCHED]: Fix OOPS when removing devices from a teql queuing discipline

[ Upstream commit: 4f9f8311a08c0d95c70261264a2b47f2ae99683a ]

tecl_reset() is called from deactivate and qdisc is set to noop already,
but subsequent teql_xmit does not know about it and dereference private
data as teql qdisc and thus oopses.
not catch it first :)

Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Adrian Bunk <bunk@kernel.org>

diff --git a/net/sched/sch_teql.c b/net/sched/sch_teql.c
index 79b8ef34c6e4c9b14d5d877ba64f0a496701e316..e7dc750ecade790ac115c1e098aecd695c81d516 100644 (file)
--- a/net/sched/sch_teql.c
+++ b/net/sched/sch_teql.c
@@ -265,6 +265,9 @@ __teql_resolve(struct sk_buff *skb, struct sk_buff *skb_res, struct net_device *
 static __inline__ int
 teql_resolve(struct sk_buff *skb, struct sk_buff *skb_res, struct net_device *dev)
 {
+       if (dev->qdisc == &noop_qdisc)
+               return -ENODEV;
+
        if (dev->hard_header == NULL ||
            skb->dst == NULL ||
            skb->dst->neighbour == NULL)