[ 04/83] mac80211: sync acccess to tx_filtered/ps_tx_buf queues
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2012-11-22 21:58:25
Also in:
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3.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Arik Nemtsov <redacted> commit 987c285c2ae2e4e32aca3a9b3252d28171c75711 upstream. 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. Signed-off-by: Arik Nemtsov <redacted> Signed-off-by: Ido Yariv <redacted> Signed-off-by: Johannes Berg <redacted> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/mac80211/sta_info.c | 5 +++++ 1 file changed, 5 insertions(+)
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c@@ -948,6 +948,7 @@ void ieee80211_sta_ps_deliver_wakeup(str 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);
@@ -963,12 +964,16 @@ void ieee80211_sta_ps_deliver_wakeup(str 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; }