wifi: mt76: mt7996: fix insecure data handling of mt7996_mcu_ie_countdown()

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

Reported-by: coverity-bot <keescook+coverity-bot@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@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c
index 04e1d10..a90b7ca 100644 (file)
--- 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];