UPSTREAM: usb: gadget: rndis: prevent integer overflow in rndis_set_r…

…esponse()

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

Bug: 213172319
Cc: stable@kernel.org
Fixes: 38ea1ea ("usb: gadget: rndis: check size of RNDIS_MSG_SET command")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20220301080424.GA17208@kili
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 65f3324)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I16c7c6c5a0a3a0102d1c6c9ddfca2a1ad1106880
(cherry picked from commit 9f93861)

drivers/usb/gadget/function/rndis.c

@@ -640,6 +640,7 @@ static int rndis_set_response(struct rndis_params *params,
 	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;