When deleting a station or otherwise tearing down all aggregation
sessions, make sure to delete requested but not yet started ones,
to avoid the following scenario:
* session is requested, added to tid_start_tx[]
* ieee80211_ba_session_work() runs, gets past BLOCK_BA check
* ieee80211_sta_tear_down_BA_sessions() runs, locks &sta->ampdu_mlme.mtx,
e.g. while deleting the station - deleting all active sessions
* ieee80211_ba_session_work() continues since tear down flushes it, and
calls ieee80211_tx_ba_session_handle_start() for the new session, arms
the timer for it
* station deletion continues to __cleanup_single_sta() and frees the
session struct, while the timer is armed
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
33ddd81e2b