commit 0a21a3eb9fcea0609f3bc8bee1f796788e0a770e
author Dan Carpenter <dan.carpenter@oracle.com> Tue Mar 01 11:04:24 2022 +0300
committer Lee Jones <joneslee@google.com> Thu Aug 04 11:54:13 2022 +0000
tree 58fd236e94a510cefa1ddcad6ad56dc66ecdd7dc
parent d9d8680e9f7c32c493e9e15d60aa281733c2c3ae

BACKPORT: usb: gadget: rndis: prevent integer overflow in rndis_set_response()

commit 65f3324f4b6fed78b8761c3b74615ecf0ffa81fa upstream.

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

Bug: 239842288
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>
Signed-off-by: Lee Jones <joneslee@google.com>
Change-Id: I4dcecb9ada2680a4211e5ccc9b27de2df964e404

drivers/usb/gadget/function/rndis.c

diff --git a/drivers/usb/gadget/function/rndis.c b/drivers/usb/gadget/function/rndis.c
index 0f14c52..4150de9 100644
--- a/drivers/usb/gadget/function/rndis.c
+++ b/drivers/usb/gadget/function/rndis.c
@@ -640,6 +640,7 @@
 	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;