From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Tue, 9 Sep 2014 12:05:28 +0000 (-0300)
Subject: [media] dvb: si21xx: buffer overflow in si21_writeregs()
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=cf3b576d52c1f0a204f0c8bdecc22a338f7ca5a4;p=openwrt%2Fstaging%2Fblogic.git

[media] dvb: si21xx: buffer overflow in si21_writeregs()

"len" is user controlled and can be up to 255.  Anything more than 59
will cause a buffer overflow so we need to add a test for that.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
---

diff --git a/drivers/media/dvb-frontends/si21xx.c b/drivers/media/dvb-frontends/si21xx.c
index 73b47cc6a13b..16850e2bf02f 100644
--- a/drivers/media/dvb-frontends/si21xx.c
+++ b/drivers/media/dvb-frontends/si21xx.c
@@ -236,6 +236,9 @@ static int si21_writeregs(struct si21xx_state *state, u8 reg1,
 				.len = len + 1
 	};
 
+	if (len > sizeof(buf) - 1)
+		return -EINVAL;
+
 	msg.buf[0] =  reg1;
 	memcpy(msg.buf + 1, data, len);