2021-04-27 10:07:53

by Lorenzo Bianconi

[permalink] [raw]
Subject: [PATCH] mt76: mt7615: fix NULL pointer dereference in tx_prepare_skb()

Fix theoretical NULL pointer dereference in mt7615_tx_prepare_skb and
mt7663_usb_sdio_tx_prepare_skb routines. This issue has been identified
by code analysis.

Fixes: 6aa4ed7927f11 ("mt76: mt7615: implement DMA support for MT7622")
Fixes: 4bb586bc33b98 ("mt76: mt7663u: sync probe sampling with rate configuration")
Signed-off-by: Lorenzo Bianconi <[email protected]>
---
drivers/net/wireless/mediatek/mt76/mt7615/pci_mac.c | 5 +++--
drivers/net/wireless/mediatek/mt76/mt7615/usb_sdio.c | 5 +++--
2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/pci_mac.c b/drivers/net/wireless/mediatek/mt76/mt7615/pci_mac.c
index d7cbef752f9f..cc278d8cb888 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7615/pci_mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7615/pci_mac.c
@@ -131,20 +131,21 @@ int mt7615_tx_prepare_skb(struct mt76_dev *mdev, void *txwi_ptr,
struct mt76_tx_info *tx_info)
{
struct mt7615_dev *dev = container_of(mdev, struct mt7615_dev, mt76);
- struct mt7615_sta *msta = container_of(wcid, struct mt7615_sta, wcid);
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx_info->skb);
struct ieee80211_key_conf *key = info->control.hw_key;
int pid, id;
u8 *txwi = (u8 *)txwi_ptr;
struct mt76_txwi_cache *t;
+ struct mt7615_sta *msta;
void *txp;

+ msta = wcid ? container_of(wcid, struct mt7615_sta, wcid) : NULL;
if (!wcid)
wcid = &dev->mt76.global_wcid;

pid = mt76_tx_status_skb_add(mdev, wcid, tx_info->skb);

- if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) {
+ if ((info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) && msta) {
struct mt7615_phy *phy = &dev->phy;

if ((info->hw_queue & MT_TX_HW_QUEUE_EXT_PHY) && mdev->phy2)
diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/usb_sdio.c b/drivers/net/wireless/mediatek/mt76/mt7615/usb_sdio.c
index f8d3673c2cae..7010101f6b14 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7615/usb_sdio.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7615/usb_sdio.c
@@ -191,14 +191,15 @@ int mt7663_usb_sdio_tx_prepare_skb(struct mt76_dev *mdev, void *txwi_ptr,
struct ieee80211_sta *sta,
struct mt76_tx_info *tx_info)
{
- struct mt7615_sta *msta = container_of(wcid, struct mt7615_sta, wcid);
struct mt7615_dev *dev = container_of(mdev, struct mt7615_dev, mt76);
struct sk_buff *skb = tx_info->skb;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+ struct mt7615_sta *msta;
int pad;

+ msta = wcid ? container_of(wcid, struct mt7615_sta, wcid) : NULL;
if ((info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) &&
- !msta->rate_probe) {
+ msta && !msta->rate_probe) {
/* request to configure sampling rate */
spin_lock_bh(&dev->mt76.lock);
mt7615_mac_set_rates(&dev->phy, msta, &info->control.rates[0],
--
2.30.2