[PATCH 2/4] wifi: mt76: mt7996: fix insecure data handling of mt7996_mcu_ie_countdown()

[Ryder Lee]

Coverity message:
using tainted "hdr->band" variable as an index into an array "(*dev).mt76.phys".

Reported-by: coverity-bot <keescook+coverity-bot at chromium.org>
Addresses-Coverity-ID: 1527797 ("Insecure data handling")
Fixes: 98686cd21624 ("wifi: mt76: mt7996: add driver for MediaTek Wi-Fi 7 (802.11be) devices")
Signed-off-by: Ryder Lee <ryder.lee at mediatek.com>
---
 drivers/net/wireless/mediatek/mt76/mt7996/mcu.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c
index 04e1d10bbd21..a90b7ca2df63 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c
@@ -412,6 +412,9 @@ mt7996_mcu_ie_countdown(struct mt7996_dev *dev, struct sk_buff *skb)
 	struct header *hdr = (struct header *)data;
 	struct tlv *tlv = (struct tlv *)(data + 4);
 
+	if (hdr->band >= ARRAY_SIZE(dev->mt76.phys))
+		return;
+
 	if (hdr->band && dev->mt76.phys[hdr->band])
 		mphy = dev->mt76.phys[hdr->band];
 
-- 
2.18.0