From: Alyssa Milburn <amilburn@zall.org>
Date: Sat, 1 Apr 2017 17:33:42 +0000 (-0300)
Subject: [media] digitv: limit messages to buffer size
X-Git-Tag: v4.12-rc1~85^2~24
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=821117dc21083a99dd99174c10848d70ff43de29;p=linux.git

[media] digitv: limit messages to buffer size

Return an error rather than memcpy()ing beyond the end of the buffer.
Internal callers use appropriate sizes, but digitv_i2c_xfer may not.

Signed-off-by: Alyssa Milburn <amilburn@zall.org>
Cc: stable@vger.kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
---

diff --git a/drivers/media/usb/dvb-usb/digitv.c b/drivers/media/usb/dvb-usb/digitv.c
index 4284f6984dc1..475a3c0cdee7 100644
--- a/drivers/media/usb/dvb-usb/digitv.c
+++ b/drivers/media/usb/dvb-usb/digitv.c
@@ -33,6 +33,9 @@ static int digitv_ctrl_msg(struct dvb_usb_device *d,
 
 	wo = (rbuf == NULL || rlen == 0); /* write-only */
 
+	if (wlen > 4 || rlen > 4)
+		return -EIO;
+
 	memset(st->sndbuf, 0, 7);
 	memset(st->rcvbuf, 0, 7);