mac80211: fix some RX aggregation locking

A few places in mac80211 do not currently acquire
the sta lock for RX aggregation, but they should.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/rx.c

@@ -720,14 +720,16 @@ static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx,
 
 	tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
 
+	spin_lock(&sta->lock);
+
 	if (!sta->ampdu_mlme.tid_active_rx[tid])
-		goto dont_reorder;
+		goto dont_reorder_unlock;
 
 	tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
 
 	/* qos null data frames are excluded */
 	if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
-		goto dont_reorder;
+		goto dont_reorder_unlock;
 
 	/* new, potentially un-ordered, ampdu frame - process it */
 
@@ -739,15 +741,20 @@ static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx,
 	/* if this mpdu is fragmented - terminate rx aggregation session */
 	sc = le16_to_cpu(hdr->seq_ctrl);
 	if (sc & IEEE80211_SCTL_FRAG) {
+		spin_unlock(&sta->lock);
 		__ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
 					       WLAN_REASON_QSTA_REQUIRE_SETUP);
 		dev_kfree_skb(skb);
 		return;
 	}
 
-	if (ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb, frames))
+	if (ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb, frames)) {
+		spin_unlock(&sta->lock);
 		return;
+	}
 
+ dont_reorder_unlock:
+	spin_unlock(&sta->lock);
  dont_reorder:
 	__skb_queue_tail(frames, skb);
 }
@@ -1804,9 +1811,12 @@ ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx, struct sk_buff_head *frames)
 	if (ieee80211_is_back_req(bar->frame_control)) {
 		if (!rx->sta)
 			return RX_DROP_MONITOR;
+		spin_lock(&rx->sta->lock);
 		tid = le16_to_cpu(bar->control) >> 12;
-		if (!rx->sta->ampdu_mlme.tid_active_rx[tid])
+		if (!rx->sta->ampdu_mlme.tid_active_rx[tid]) {
+			spin_unlock(&rx->sta->lock);
 			return RX_DROP_MONITOR;
+		}
 		tid_agg_rx = rx->sta->ampdu_mlme.tid_rx[tid];
 
 		start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
@@ -1820,6 +1830,7 @@ ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx, struct sk_buff_head *frames)
 		ieee80211_release_reorder_frames(hw, tid_agg_rx, start_seq_num,
 						 frames);
 		kfree_skb(skb);
+		spin_unlock(&rx->sta->lock);
 		return RX_QUEUED;
 	}