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 (file)
--- 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;