mac80211: further RCU fixes

There were a few more instances of sta_info_get calls not being
protected by RCU, fix them.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/cfg.c

@@ -718,12 +718,18 @@ static int ieee80211_del_station(struct wiphy *wiphy, struct net_device *dev,
 	struct sta_info *sta;
 
 	if (mac) {
+		rcu_read_lock();
+
 		/* XXX: get sta belonging to dev */
 		sta = sta_info_get(local, mac);
-		if (!sta)
+		if (!sta) {
+			rcu_read_unlock();
 			return -ENOENT;
+		}
 
 		sta_info_unlink(&sta);
+		rcu_read_unlock();
+
 		sta_info_destroy(sta);
 	} else
 		sta_info_flush(local, sdata);
@@ -740,17 +746,23 @@ static int ieee80211_change_station(struct wiphy *wiphy,
 	struct sta_info *sta;
 	struct ieee80211_sub_if_data *vlansdata;
 
+	rcu_read_lock();
+
 	/* XXX: get sta belonging to dev */
 	sta = sta_info_get(local, mac);
-	if (!sta)
+	if (!sta) {
+		rcu_read_unlock();
 		return -ENOENT;
+	}
 
 	if (params->vlan && params->vlan != sta->sdata->dev) {
 		vlansdata = IEEE80211_DEV_TO_SUB_IF(params->vlan);
 
 		if (vlansdata->vif.type != IEEE80211_IF_TYPE_VLAN ||
-		    vlansdata->vif.type != IEEE80211_IF_TYPE_AP)
+		    vlansdata->vif.type != IEEE80211_IF_TYPE_AP) {
+			rcu_read_unlock();
 			return -EINVAL;
+		}
 
 		sta->sdata = IEEE80211_DEV_TO_SUB_IF(params->vlan);
 		ieee80211_send_layer2_update(sta);
@@ -758,6 +770,8 @@ static int ieee80211_change_station(struct wiphy *wiphy,
 
 	sta_apply_parameters(local, sta, params);
 
+	rcu_read_unlock();
+
 	return 0;
 }
 

net/mac80211/wext.c

@@ -980,6 +980,8 @@ static struct iw_statistics *ieee80211_get_wireless_stats(struct net_device *dev
 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 	struct sta_info *sta = NULL;
 
+	rcu_read_lock();
+
 	if (sdata->vif.type == IEEE80211_IF_TYPE_STA ||
 	    sdata->vif.type == IEEE80211_IF_TYPE_IBSS)
 		sta = sta_info_get(local, sdata->u.sta.bssid);
@@ -996,6 +998,9 @@ static struct iw_statistics *ieee80211_get_wireless_stats(struct net_device *dev
 		wstats->qual.noise = sta->last_noise;
 		wstats->qual.updated = local->wstats_flags;
 	}
+
+	rcu_read_unlock();
+
 	return wstats;
 }