wifi: mt76: Fix possible oob access in mt76_connac2_mac_write_txwi_80211()

Check frame length before accessing the mgmt fields in
mt76_connac2_mac_write_txwi_80211 in order to avoid a possible oob
access.

Fixes: 577dbc6c656d ("mt76: mt7915: enable offloading of sequence number assignment")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/20260226-mt76-addba-req-oob-access-v1-3-b0f6d1ad4850@kernel.org
[fix check to also cover mgmt->u.action.u.addba_req.capab,
correct Fixes tag]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/drivers/net/wireless/mediatek/mt76/mt76_connac_mac.c b/drivers/net/wireless/mediatek/mt76/mt76_connac_mac.c
index 3304b5971be09e4c20178bdff66febf67bcd5c19..b41ca1410da922ecec63da25520ff87f0baf82d7 100644 (file)
--- a/drivers/net/wireless/mediatek/mt76/mt76_connac_mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76_connac_mac.c
@@ -413,6 +413,7 @@ mt76_connac2_mac_write_txwi_80211(struct mt76_dev *dev, __le32 *txwi,
        u32 val;
 
        if (ieee80211_is_action(fc) &&
+           skb->len >= IEEE80211_MIN_ACTION_SIZE + 1 + 1 + 2 &&
            mgmt->u.action.category == WLAN_CATEGORY_BACK &&
            mgmt->u.action.u.addba_req.action_code == WLAN_ACTION_ADDBA_REQ) {
                u16 capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);