From: Johannes Berg <johannes.berg@intel.com>
Date: Fri, 22 Feb 2013 11:55:01 +0000 (+0100)
Subject: mac80211: fix tim_lock locking
X-Git-Tag: v3.9-rc2~24^2~15^2^2~14
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=1b91731d23a3dd8e8d7e3ee21b8c6d6d4cde62c1;p=platform%2Fkernel%2Flinux-stable.git

mac80211: fix tim_lock locking

The ieee80211_beacon_add_tim() function might be called
by drivers with BHs enabled, which causes a potential
deadlock if TX happens at the same time and attempts to
lock the tim_lock as well. Use spin_lock_bh to fix it.

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

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 5b9602b..5800c7a 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -2360,9 +2360,9 @@ static int ieee80211_beacon_add_tim(struct ieee80211_sub_if_data *sdata,
 	if (local->tim_in_locked_section) {
 		__ieee80211_beacon_add_tim(sdata, ps, skb);
 	} else {
-		spin_lock(&local->tim_lock);
+		spin_lock_bh(&local->tim_lock);
 		__ieee80211_beacon_add_tim(sdata, ps, skb);
-		spin_unlock(&local->tim_lock);
+		spin_unlock_bh(&local->tim_lock);
 	}
 
 	return 0;