From 65f3324f4b6fed78b8761c3b74615ecf0ffa81fa Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Tue, 1 Mar 2022 11:04:24 +0300
Subject: [PATCH] usb: gadget: rndis: prevent integer overflow in rndis_set_response()
Git-commit: 65f3324f4b6fed78b8761c3b74615ecf0ffa81fa
Patch-mainline: v5.17
References: git-fixes

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

Cc: stable@kernel.org
Fixes: 38ea1eac7d88 ("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>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/usb/gadget/function/rndis.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/usb/gadget/function/rndis.c b/drivers/usb/gadget/function/rndis.c
index 00b3f6b3bb31..713efd9aefde 100644
--- a/drivers/usb/gadget/function/rndis.c
+++ b/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;
 
-- 
2.31.1