mac80211: sync acccess to tx_filtered/ps_tx_buf queues
These are accessed without a lock when ending STA PSM. If the
sta_cleanup timer accesses these lists at the same time, we might crash.
This may fix some mysterious crashes we had during
ieee80211_sta_ps_deliver_wakeup.
Cc: stable@vger.kernel.org
Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: Ido Yariv <ido@wizery.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 797dd36..89ccd3e 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -961,6 +961,7 @@
struct ieee80211_local *local = sdata->local;
struct sk_buff_head pending;
int filtered = 0, buffered = 0, ac;
+ unsigned long flags;
clear_sta_flag(sta, WLAN_STA_SP);
@@ -976,12 +977,16 @@
for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
int count = skb_queue_len(&pending), tmp;
+ spin_lock_irqsave(&sta->tx_filtered[ac].lock, flags);
skb_queue_splice_tail_init(&sta->tx_filtered[ac], &pending);
+ spin_unlock_irqrestore(&sta->tx_filtered[ac].lock, flags);
tmp = skb_queue_len(&pending);
filtered += tmp - count;
count = tmp;
+ spin_lock_irqsave(&sta->ps_tx_buf[ac].lock, flags);
skb_queue_splice_tail_init(&sta->ps_tx_buf[ac], &pending);
+ spin_unlock_irqrestore(&sta->ps_tx_buf[ac].lock, flags);
tmp = skb_queue_len(&pending);
buffered += tmp - count;
}