Starting from mac80211 commitadf8ed01e4
("mac80211: add an optional TXQ for other PS-buffered frames") and commit0eeb2b674f
("mac80211: add an option for station management TXQ") a new per-sta queue has been introduced for bufferable management frames. sta->txq[IEEE80211_NUM_TIDS] is initialized just if the driver reports the following hw flags: - IEEE80211_HW_STA_MMPDU_TXQ - IEEE80211_HW_BUFF_MMPDU_TXQ This can produce a NULL pointer dereference in mt76_stop_tx_queues since mt76 iterates on all available sta tx queues assuming they are initialized by mac80211. This issue has been spotted analyzing the code (it has not triggered any crash yet) Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com> Signed-off-by: Kalle Valo <kvalo@codeaurora.org>