wifi: mt76: mt7925: Fix possible oob access in mt7925_mac_write_txwi_80211()

[ Upstream commit c41a9ab ]

Check frame length before accessing the mgmt fields in
mt7925_mac_write_txwi_80211 in order to avoid a possible oob access.

Fixes: c948b5d ("wifi: mt76: mt7925: add Mediatek Wi-Fi7 driver for mt7925 chips")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/20260226-mt76-addba-req-oob-access-v1-2-b0f6d1ad4850@kernel.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: LorenzoBianconi

drivers/net/wireless/mediatek/mt76/mt7925/mac.c

@@ -671,6 +671,7 @@ mt7925_mac_write_txwi_80211(struct mt76_dev *dev, __le32 *txwi,
 	u32 val;
 
 	if (ieee80211_is_action(fc) &&
+	    skb->len >= IEEE80211_MIN_ACTION_SIZE + 1 &&
 	    mgmt->u.action.category == WLAN_CATEGORY_BACK &&
 	    mgmt->u.action.u.addba_req.action_code == WLAN_ACTION_ADDBA_REQ)
 		tid = MT_TX_ADDBA;