[PATCH] mac80211: don't stop a single aggregation session twice
From: Johannes Berg <johannes@sipsolutions.net>
Date: 2011-11-24 19:06:18
From: Johannes Berg <redacted> Nikolay noticed (by code review) that mac80211 can attempt to stop an aggregation session while it is already being stopped. So to fix it, check whether stop is already being done and bail out if so. Also move setting the STOPPING state into the lock so things are properly atomic. Cc: stable@vger.kernel.org Reported-by: Nikolay Martynov <redacted> Signed-off-by: Johannes Berg <redacted> --- net/mac80211/agg-tx.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
--- a/net/mac80211/agg-tx.c 2011-11-24 20:03:36.000000000 +0100
+++ b/net/mac80211/agg-tx.c 2011-11-24 20:03:49.000000000 +0100@@ -162,6 +162,12 @@ int ___ieee80211_stop_tx_ba_session(stru return -ENOENT; } + /* if we're already stopping ignore any new requests to stop */ + if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { + spin_unlock_bh(&sta->lock); + return -EALREADY; + } + if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) { /* not even started yet! */ ieee80211_assign_tid_tx(sta, tid, NULL);
@@ -170,6 +176,8 @@ int ___ieee80211_stop_tx_ba_session(stru return 0; } + set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state); + spin_unlock_bh(&sta->lock); #ifdef CONFIG_MAC80211_HT_DEBUG
@@ -177,8 +185,6 @@ int ___ieee80211_stop_tx_ba_session(stru sta->sta.addr, tid); #endif /* CONFIG_MAC80211_HT_DEBUG */ - set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state); - del_timer_sync(&tid_tx->addba_resp_timer); /*