[PATCH] rtw89: Fix variable dereferenced before check 'sta'

[PATCH] rtw89: Fix variable dereferenced before check 'sta'

[Ping-Ke Shih]

The pointer rtwsta is dereferencing pointer sta before sta is being null
checked. Fix this by assigning sta->drv_priv to rtwsta only if sta is not
NULL, otherwise just NULL.

Fixes: e3ec7017f6a2 ("rtw89: add Realtek 802.11ax driver")
Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
---
 drivers/net/wireless/realtek/rtw89/core.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtw89/core.c b/drivers/net/wireless/realtek/rtw89/core.c
index 06fb6e5b1b37..d02ec5a735cb 100644
--- a/drivers/net/wireless/realtek/rtw89/core.c
+++ b/drivers/net/wireless/realtek/rtw89/core.c
@@ -1412,7 +1412,7 @@ static void rtw89_core_ba_work(struct work_struct *work)
 	list_for_each_entry_safe(rtwtxq, tmp, &rtwdev->ba_list, list) {
 		struct ieee80211_txq *txq = rtw89_txq_to_txq(rtwtxq);
 		struct ieee80211_sta *sta = txq->sta;
-		struct rtw89_sta *rtwsta = (struct rtw89_sta *)sta->drv_priv;
+		struct rtw89_sta *rtwsta = sta ? (struct rtw89_sta *)sta->drv_priv : NULL;
 		u8 tid = txq->tid;
 
 		if (!sta) {
@@ -1462,7 +1462,7 @@ static void rtw89_core_txq_check_agg(struct rtw89_dev *rtwdev,
 	struct ieee80211_hw *hw = rtwdev->hw;
 	struct ieee80211_txq *txq = rtw89_txq_to_txq(rtwtxq);
 	struct ieee80211_sta *sta = txq->sta;
-	struct rtw89_sta *rtwsta = (struct rtw89_sta *)sta->drv_priv;
+	struct rtw89_sta *rtwsta = sta ? (struct rtw89_sta *)sta->drv_priv : NULL;
 
 	if (unlikely(skb_get_queue_mapping(skb) == IEEE80211_AC_VO))
 		return;
@@ -1534,7 +1534,7 @@ static bool rtw89_core_txq_agg_wait(struct rtw89_dev *rtwdev,
 {
 	struct rtw89_txq *rtwtxq = (struct rtw89_txq *)txq->drv_priv;
 	struct ieee80211_sta *sta = txq->sta;
-	struct rtw89_sta *rtwsta = (struct rtw89_sta *)sta->drv_priv;
+	struct rtw89_sta *rtwsta = sta ? (struct rtw89_sta *)sta->drv_priv : NULL;
 
 	if (!sta || rtwsta->max_agg_wait <= 0)
 		return false;
-- 
2.25.1

Re: [PATCH] rtw89: Fix variable dereferenced before check 'sta'

[Kalle Valo]

Ping-Ke Shih <pkshih@realtek.com> wrote:

> The pointer rtwsta is dereferencing pointer sta before sta is being null
> checked. Fix this by assigning sta->drv_priv to rtwsta only if sta is not
> NULL, otherwise just NULL.
> 
> Fixes: e3ec7017f6a2 ("rtw89: add Realtek 802.11ax driver")
> Reported-by: Colin Ian King <colin.king@canonical.com>
> Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>

Patch applied to wireless-drivers-next.git, thanks.

5d44f0672319 rtw89: Fix variable dereferenced before check 'sta'

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/20211022061242.8383-1-pkshih@realtek.com/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches