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authorJohannes Berg <johannes@sipsolutions.net>2009-02-10 21:25:51 +0100
committerJohn W. Linville <linville@tuxdriver.com>2009-02-13 13:45:43 -0500
commit55687e380a3965ac448e03281e027553a6ae6dac (patch)
treeba7c079d3ce4d7278eeb45317ba3baf54f45c96c /net/mac80211/sta_info.c
parent23e6a7ea5cb1a902d37ab0c783709c178fa834df (diff)
mac80211: fix aggregation timer lockups
As far as I can tell, there are possible lockups because both the RX session_timer and TX addba_resp_timer are del_timer_sync'ed under the sta spinlock which both timer functions take. Additionally, the TX agg code seems to leak memory when TX aggregation is not disabled before the sta_info is freed. Fix this by making the free code a little smarter in the RX agg case, and actually make the sta_info_destroy code free the TX agg info in the TX agg case. We won't notify the peer, but it'll notice something is wrong anyway, and normally this only happens after we've told it in some other way we will no longer talk to it. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'net/mac80211/sta_info.c')
-rw-r--r--net/mac80211/sta_info.c37
1 files changed, 33 insertions, 4 deletions
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 10c5539c20a..634f65c0130 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -194,12 +194,41 @@ void sta_info_destroy(struct sta_info *sta)
dev_kfree_skb_any(skb);
for (i = 0; i < STA_TID_NUM; i++) {
+ struct tid_ampdu_rx *tid_rx;
+ struct tid_ampdu_tx *tid_tx;
+
spin_lock_bh(&sta->lock);
- if (sta->ampdu_mlme.tid_rx[i])
- del_timer_sync(&sta->ampdu_mlme.tid_rx[i]->session_timer);
- if (sta->ampdu_mlme.tid_tx[i])
- del_timer_sync(&sta->ampdu_mlme.tid_tx[i]->addba_resp_timer);
+ tid_rx = sta->ampdu_mlme.tid_rx[i];
+ /* Make sure timer won't free the tid_rx struct, see below */
+ if (tid_rx)
+ tid_rx->shutdown = true;
spin_unlock_bh(&sta->lock);
+
+ /*
+ * Outside spinlock - shutdown is true now so that the timer
+ * won't free tid_rx, we have to do that now. Can't let the
+ * timer do it because we have to sync the timer outside the
+ * lock that it takes itself.
+ */
+ if (tid_rx) {
+ del_timer_sync(&tid_rx->session_timer);
+ kfree(tid_rx);
+ }
+
+ /*
+ * No need to do such complications for TX agg sessions, the
+ * path leading to freeing the tid_tx struct goes via a call
+ * from the driver, and thus needs to look up the sta struct
+ * again, which cannot be found when we get here. Hence, we
+ * just need to delete the timer and free the aggregation
+ * info; we won't be telling the peer about it then but that
+ * doesn't matter if we're not talking to it again anyway.
+ */
+ tid_tx = sta->ampdu_mlme.tid_tx[i];
+ if (tid_tx) {
+ del_timer_sync(&tid_tx->addba_resp_timer);
+ kfree(tid_tx);
+ }
}
__sta_info_free(local, sta);