mac80211: fix TX aggregation session timer
In commit 12d3952fc4a1cd96234bc7023bf7eefeb0bb6355
("mac80211: optimize aggregation session timeout handling")
two bugs were introduced:
1) RCU usage was completely broken since no locks are held
2) the timer must not rearm when agg session is stopping
Reported-and-tested-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c
index 5b7053c..7cf0715 100644
--- a/net/mac80211/agg-tx.c
+++ b/net/mac80211/agg-tx.c
@@ -421,16 +421,22 @@
struct tid_ampdu_tx *tid_tx;
unsigned long timeout;
- tid_tx = rcu_dereference_protected_tid_tx(sta, *ptid);
- if (!tid_tx)
+ rcu_read_lock();
+ tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[*ptid]);
+ if (!tid_tx || test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
+ rcu_read_unlock();
return;
+ }
timeout = tid_tx->last_tx + TU_TO_JIFFIES(tid_tx->timeout);
if (time_is_after_jiffies(timeout)) {
mod_timer(&tid_tx->session_timer, timeout);
+ rcu_read_unlock();
return;
}
+ rcu_read_unlock();
+
#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "tx session timer expired on tid %d\n", (u16)*ptid);
#endif