This is a note to let you know that I've just added the patch titled mt76: mt7615: fix a possible NULL pointer dereference in mt7615_pm_wake_work to the 5.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mt76-mt7615-fix-a-possible-null-pointer-dereference-.patch and it can be found in the queue-5.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit b58ce37d6b51ccc159548e389d86a7b71163ed09 Author: Lorenzo Bianconi <lorenzo@xxxxxxxxxx> Date: Fri Aug 21 12:09:54 2020 +0200 mt76: mt7615: fix a possible NULL pointer dereference in mt7615_pm_wake_work [ Upstream commit a081de174d11b12db9a94eb748041c2732f14c10 ] Initialize wcid to global_wcid if msta is NULL in mt7615_pm_wake_work routine since wcid will be dereferenced running mt76_tx() Fixes: 2b8cdfb28d340 ("mt76: mt7615: wake device before pushing frames in mt7615_tx") Signed-off-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx> Signed-off-by: Felix Fietkau <nbd@xxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c index 3dd8dd28690ed..2be127018df6a 100644 --- a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c +++ b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c @@ -1853,12 +1853,13 @@ void mt7615_pm_wake_work(struct work_struct *work) spin_lock_bh(&dev->pm.txq_lock); for (i = 0; i < IEEE80211_NUM_ACS; i++) { struct mt7615_sta *msta = dev->pm.tx_q[i].msta; - struct mt76_wcid *wcid = msta ? &msta->wcid : NULL; struct ieee80211_sta *sta = NULL; + struct mt76_wcid *wcid; if (!dev->pm.tx_q[i].skb) continue; + wcid = msta ? &msta->wcid : &dev->mt76.global_wcid; if (msta && wcid->sta) sta = container_of((void *)msta, struct ieee80211_sta, drv_priv);