[PATCH 1/2] wifi: mt76: mt7925: validate skb length in testmode query

[Aviel Zohar <avielzohar123@gmail.com>]

In mt7925_tm_query(), the response skb from mt76_mcu_send_and_get_msg()
is used in a memcpy without validating its length:

  memcpy(evt_resp, skb->data + 8, MT7925_EVT_RSP_LEN);

where MT7925_EVT_RSP_LEN is 512. If the firmware returns a response
shorter than 520 bytes (8 + 512), this reads beyond the skb data
buffer. The over-read data is then returned to userspace via nla_put()
in mt7925_testmode_dump().

Add a length check before the memcpy to ensure the skb contains
sufficient data.

Fixes: c948b5da6bbe ("wifi: mt76: mt7925: add Mediatek Wi-Fi7 driver for mt7925 chips")
Signed-off-by: Aviel Zohar <avielzohar123@gmail.com>
---
 drivers/net/wireless/mediatek/mt76/mt7925/testmode.c | 5 +++++
 1 file changed, 5 insertions(+)

--- a/drivers/net/wireless/mediatek/mt76/mt7925/testmode.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7925/testmode.c
@@ -105,6 +105,11 @@
 	if (ret)
 		goto out;
 
+	if (skb->len < MT7925_EVT_RSP_LEN + 8) {
+		ret = -EINVAL;
+		goto out;
+	}
+
 	memcpy((char *)evt_resp, (char *)skb->data + 8, MT7925_EVT_RSP_LEN);
 
 out: