This is a note to let you know that I've just added the patch titled wifi: mt76: mt7921: fix deadlock in mt7921_abort_roc to the 6.2-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: wifi-mt76-mt7921-fix-deadlock-in-mt7921_abort_roc.patch and it can be found in the queue-6.2 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 8c2a46b825eaca51c7a2e24de9967b97c260f07b Author: Felix Fietkau <nbd@xxxxxxxx> Date: Wed Dec 21 11:47:47 2022 +0100 wifi: mt76: mt7921: fix deadlock in mt7921_abort_roc [ Upstream commit de19b9c83654e323d83f839a550ca4af37fea15b ] When mt7921_abort_roc is called with dev->mutex held, it can deadlock while calling cancel_work_sync(&phy->roc_work), because the work function could be waiting to acquire the mutex. Fix this by flushing the work before taking the mutex Reported-by: Mikhail Gavrilov <mikhail.v.gavrilov@xxxxxxxxx> Fixes: 034ae28b56f1 ("wifi: mt76: mt7921: introduce remain_on_channel support") Fixes: 41ac53c899bd ("wifi: mt76: mt7921: introduce chanctx support") Signed-off-by: Felix Fietkau <nbd@xxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/main.c b/drivers/net/wireless/mediatek/mt76/mt7921/main.c index 76ac5069638fe..722df8eea91f7 100644 --- a/drivers/net/wireless/mediatek/mt76/mt7921/main.c +++ b/drivers/net/wireless/mediatek/mt76/mt7921/main.c @@ -422,15 +422,15 @@ void mt7921_roc_timer(struct timer_list *timer) static int mt7921_abort_roc(struct mt7921_phy *phy, struct mt7921_vif *vif) { - int err; - - if (!test_and_clear_bit(MT76_STATE_ROC, &phy->mt76->state)) - return 0; + int err = 0; del_timer_sync(&phy->roc_timer); cancel_work_sync(&phy->roc_work); - err = mt7921_mcu_abort_roc(phy, vif, phy->roc_token_id); - clear_bit(MT76_STATE_ROC, &phy->mt76->state); + + mt7921_mutex_acquire(phy->dev); + if (test_and_clear_bit(MT76_STATE_ROC, &phy->mt76->state)) + err = mt7921_mcu_abort_roc(phy, vif, phy->roc_token_id); + mt7921_mutex_release(phy->dev); return err; } @@ -487,13 +487,8 @@ static int mt7921_cancel_remain_on_channel(struct ieee80211_hw *hw, { struct mt7921_vif *mvif = (struct mt7921_vif *)vif->drv_priv; struct mt7921_phy *phy = mt7921_hw_phy(hw); - int err; - mt7921_mutex_acquire(phy->dev); - err = mt7921_abort_roc(phy, mvif); - mt7921_mutex_release(phy->dev); - - return err; + return mt7921_abort_roc(phy, mvif); } static int mt7921_set_channel(struct mt7921_phy *phy) @@ -1778,11 +1773,8 @@ static void mt7921_mgd_complete_tx(struct ieee80211_hw *hw, struct ieee80211_prep_tx_info *info) { struct mt7921_vif *mvif = (struct mt7921_vif *)vif->drv_priv; - struct mt7921_dev *dev = mt7921_hw_dev(hw); - mt7921_mutex_acquire(dev); mt7921_abort_roc(mvif->phy, mvif); - mt7921_mutex_release(dev); } const struct ieee80211_ops mt7921_ops = {