This is a note to let you know that I've just added the patch titled mt76: mt7615: fix skb use-after-free on mac reset to the 5.14-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-skb-use-after-free-on-mac-reset.patch and it can be found in the queue-5.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From b5cd1fd6043bbb7c5810067b5f93f3016bfd8a6f Mon Sep 17 00:00:00 2001 From: Felix Fietkau <nbd@xxxxxxxx> Date: Wed, 21 Jul 2021 07:23:46 +0200 Subject: mt76: mt7615: fix skb use-after-free on mac reset From: Felix Fietkau <nbd@xxxxxxxx> commit b5cd1fd6043bbb7c5810067b5f93f3016bfd8a6f upstream. When clearing all existing pending tx slots, mt76_tx_complete_skb needs to be used to free the skbs, to ensure that they are cleared from the status list as well. Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Felix Fietkau <nbd@xxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/wireless/mediatek/mt76/mt7615/mac.c | 45 ++++++++++++------------ 1 file changed, 23 insertions(+), 22 deletions(-) --- a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c +++ b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c @@ -1494,32 +1494,41 @@ out: } static void -mt7615_mac_tx_free_token(struct mt7615_dev *dev, u16 token) +mt7615_txwi_free(struct mt7615_dev *dev, struct mt76_txwi_cache *txwi) { struct mt76_dev *mdev = &dev->mt76; - struct mt76_txwi_cache *txwi; __le32 *txwi_data; u32 val; u8 wcid; - trace_mac_tx_free(dev, token); - txwi = mt76_token_put(mdev, token); - if (!txwi) - return; + mt7615_txp_skb_unmap(mdev, txwi); + if (!txwi->skb) + goto out; txwi_data = (__le32 *)mt76_get_txwi_ptr(mdev, txwi); val = le32_to_cpu(txwi_data[1]); wcid = FIELD_GET(MT_TXD1_WLAN_IDX, val); + mt76_tx_complete_skb(mdev, wcid, txwi->skb); - mt7615_txp_skb_unmap(mdev, txwi); - if (txwi->skb) { - mt76_tx_complete_skb(mdev, wcid, txwi->skb); - txwi->skb = NULL; - } - +out: + txwi->skb = NULL; mt76_put_txwi(mdev, txwi); } +static void +mt7615_mac_tx_free_token(struct mt7615_dev *dev, u16 token) +{ + struct mt76_dev *mdev = &dev->mt76; + struct mt76_txwi_cache *txwi; + + trace_mac_tx_free(dev, token); + txwi = mt76_token_put(mdev, token); + if (!txwi) + return; + + mt7615_txwi_free(dev, txwi); +} + static void mt7615_mac_tx_free(struct mt7615_dev *dev, struct sk_buff *skb) { struct mt7615_tx_free *free = (struct mt7615_tx_free *)skb->data; @@ -2026,16 +2035,8 @@ void mt7615_tx_token_put(struct mt7615_d int id; spin_lock_bh(&dev->mt76.token_lock); - idr_for_each_entry(&dev->mt76.token, txwi, id) { - mt7615_txp_skb_unmap(&dev->mt76, txwi); - if (txwi->skb) { - struct ieee80211_hw *hw; - - hw = mt76_tx_status_get_hw(&dev->mt76, txwi->skb); - ieee80211_free_txskb(hw, txwi->skb); - } - mt76_put_txwi(&dev->mt76, txwi); - } + idr_for_each_entry(&dev->mt76.token, txwi, id) + mt7615_txwi_free(dev, txwi); spin_unlock_bh(&dev->mt76.token_lock); idr_destroy(&dev->mt76.token); } Patches currently in stable-queue which might be from nbd@xxxxxxxx are queue-5.14/mt76-mt7615-fix-skb-use-after-free-on-mac-reset.patch