From: Michal Kazior <michal.kazior@tieto.com>
Date: Thu, 21 Jan 2016 13:23:07 +0000 (+0100)
Subject: mac80211: fix txq queue related crashes
X-Git-Tag: v4.6-rc1~91^2~159^2~40
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=2a58d42c1e018ad514d4e23fd33fb2ded95d3ee6;p=platform%2Fkernel%2Flinux-exynos.git

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 <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---

diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 33ae3c8..0451f12 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);
 	}