mac80211: Use queue_lock() in ieee80211_ht_agg_queue_remove().

qdisc_root_lock() is only %100 safe to use when the RTNL
semaphore is held.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 2 deletions

diff --git a/net/mac80211/wme.c b/net/mac80211/wme.c
index 28437f0001d..4310e2f6566 100644
--- a/net/mac80211/wme.c
+++ b/net/mac80211/wme.c
@@ -241,12 +241,14 @@ void ieee80211_ht_agg_queue_remove(struct ieee80211_local *local,
         } else {
                 struct netdev_queue *txq;
                 spinlock_t *root_lock;
+                struct Qdisc *q;
 
                 txq = netdev_get_tx_queue(local->mdev, agg_queue);
-                root_lock = qdisc_root_lock(txq->qdisc);
+                q = rcu_dereference(txq->qdisc);
+                root_lock = qdisc_lock(q);
 
                 spin_lock_bh(root_lock);
-                qdisc_reset(txq->qdisc);
+                qdisc_reset(q);
                 spin_unlock_bh(root_lock);
         }
 }