[PATCH 3.19.y-ckt 022/251] [media] cx24117: fix a buffer overflow when checking userspace params

[Kamal Mostafa]

3.19.8-ckt4 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Mauro Carvalho Chehab <mchehab at osg.samsung.com>

commit 82e3b88b679049f043fe9b03991d6d66fc0a43c8 upstream.

The maximum size for a DiSEqC command is 6, according to the
userspace API. However, the code allows to write up much more values:
	drivers/media/dvb-frontends/cx24116.c:983 cx24116_send_diseqc_msg() error: buffer overflow 'd->msg' 6 <= 23

Signed-off-by: Mauro Carvalho Chehab <mchehab at osg.samsung.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/media/dvb-frontends/cx24117.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/dvb-frontends/cx24117.c b/drivers/media/dvb-frontends/cx24117.c
index acb965c..af63635 100644
--- a/drivers/media/dvb-frontends/cx24117.c
+++ b/drivers/media/dvb-frontends/cx24117.c
@@ -1043,7 +1043,7 @@ static int cx24117_send_diseqc_msg(struct dvb_frontend *fe,
 	dev_dbg(&state->priv->i2c->dev, ")\n");
 
 	/* Validate length */
-	if (d->msg_len > 15)
+	if (d->msg_len > sizeof(d->msg))
 		return -EINVAL;
 
 	/* DiSEqC message */
-- 
1.9.1