| Date | Mon, 03 Dec 2012 14:31:50 +0000 | From | Ben Hutchings <> | Subject | [ 04/89] mac80211: sync acccess to tx_filtered/ps_tx_buf queues |
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3.2-stable review patch. If anyone has any objections, please let me know.
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From: Arik Nemtsov <arik@wizery.com>
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 <arik@wizery.com> Signed-off-by: Ido Yariv <ido@wizery.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- net/mac80211/sta_info.c | 5 +++++ 1 file changed, 5 insertions(+)
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 @@ void ieee80211_sta_ps_deliver_wakeup(struct sta_info *sta) 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 @@ void ieee80211_sta_ps_deliver_wakeup(struct sta_info *sta) 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; }
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