[PATCH 4.14 19/22] usb: gadget: rndis: prevent integer overflow in rndis_set_response()

[Greg Kroah-Hartman]

From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

commit 65f3324f4b6fed78b8761c3b74615ecf0ffa81fa upstream.

If "BufOffset" is very large the "BufOffset + 8" operation can have an
integer overflow.

Cc: stable@xxxxxxxxxx
Fixes: 38ea1eac7d88 ("usb: gadget: rndis: check size of RNDIS_MSG_SET command")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220301080424.GA17208@kili
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/usb/gadget/function/rndis.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/usb/gadget/function/rndis.c
+++ b/drivers/usb/gadget/function/rndis.c
@@ -643,6 +643,7 @@ static int rndis_set_response(struct rnd
 	BufLength = le32_to_cpu(buf->InformationBufferLength);
 	BufOffset = le32_to_cpu(buf->InformationBufferOffset);
 	if ((BufLength > RNDIS_MAX_TOTAL_SIZE) ||
+	    (BufOffset > RNDIS_MAX_TOTAL_SIZE) ||
 	    (BufOffset + 8 >= RNDIS_MAX_TOTAL_SIZE))
 		    return -EINVAL;