From 8cb027bb01c80130b08a9a6a5b4a0fe49a42995e Mon Sep 17 00:00:00 2001
From: MeiChia Chiu <meichia.chiu@mediatek.com>
Date: Thu, 26 Oct 2023 10:08:10 +0800
Subject: [PATCH 016/116] mtk: wifi: mt76: mt7996: Fixed null pointer
 dereference issue

Without this patch, when the station is still in Authentication stage and
sends a "Notify bandwidth change action frame" to AP at the same time,
there will be a race condition that causes a crash to occur because the AP
access "msta->vif" that has not been fully initialized.

CR-ID: WCNCR00240597
Change-Id: Ie17fbdd8ab11651a9ae0c30faac0b5ad82176e95
Signed-off-by: Bo Jiao <Bo.Jiao@mediatek.com>
Signed-off-by: Money Wang <money.wang@mediatek.com>
Signed-off-by: MeiChia Chiu <meichia.chiu@mediatek.com>
---
 mt7996/main.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/mt7996/main.c b/mt7996/main.c
index f553704ce..4fc1dd9a9 100644
--- a/mt7996/main.c
+++ b/mt7996/main.c
@@ -1079,9 +1079,16 @@ static void mt7996_sta_rc_update(struct ieee80211_hw *hw,
 				 struct ieee80211_sta *sta,
 				 u32 changed)
 {
+	struct mt7996_sta *msta = (struct mt7996_sta *)sta->drv_priv;
 	struct mt7996_phy *phy = mt7996_hw_phy(hw);
 	struct mt7996_dev *dev = phy->dev;
 
+	if (!msta->vif) {
+		dev_warn(dev->mt76.dev, "Un-initialized STA %pM wcid %d in rc_work\n",
+			 sta->addr, msta->wcid.idx);
+		return;
+	}
+
 	mt7996_sta_rc_work(&changed, sta);
 	ieee80211_queue_work(hw, &dev->rc_work);
 }
-- 
2.39.2