From 2a58d42c1e018ad514d4e23fd33fb2ded95d3ee6 Mon Sep 17 00:00:00 2001 From: Michal Kazior Date: Thu, 21 Jan 2016 14:23:07 +0100 Subject: [PATCH] mac80211: fix txq queue related crashes The driver can access the queue simultanously while mac80211 tears down the interface. Without spinlock protection this could lead to corrupting sk_buff_head and subsequently to an invalid pointer dereference. Fixes: ba8c3d6f16a1 ("mac80211: add an intermediate software queue implementation") Signed-off-by: Michal Kazior Signed-off-by: Johannes Berg --- net/mac80211/iface.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index 33ae3c81bfc5..0451f120746e 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -977,7 +977,10 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata, if (sdata->vif.txq) { struct txq_info *txqi = to_txq_info(sdata->vif.txq); + spin_lock_bh(&txqi->queue.lock); ieee80211_purge_tx_queue(&local->hw, &txqi->queue); + spin_unlock_bh(&txqi->queue.lock); + atomic_set(&sdata->txqs_len[txqi->txq.ac], 0); }