[PATCH 3.16.y-ckt 147/254] [media] ttusb-dec: buffer overflow in ioctl

[Luis Henriques]

3.16.7-ckt2 -stable review patch.  If anyone has any objections, please let me know.

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

From: Dan Carpenter <dan.carpenter at oracle.com>

commit f2e323ec96077642d397bb1c355def536d489d16 upstream.

We need to add a limit check here so we don't overflow the buffer.

Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab at osg.samsung.com>
Cc: Moritz Mühlenhoff <jmm at inutil.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/media/usb/ttusb-dec/ttusbdecfe.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/media/usb/ttusb-dec/ttusbdecfe.c b/drivers/media/usb/ttusb-dec/ttusbdecfe.c
index 5c45c9d0712d..9c29552aedec 100644
--- a/drivers/media/usb/ttusb-dec/ttusbdecfe.c
+++ b/drivers/media/usb/ttusb-dec/ttusbdecfe.c
@@ -156,6 +156,9 @@ static int ttusbdecfe_dvbs_diseqc_send_master_cmd(struct dvb_frontend* fe, struc
 		   0x00, 0x00, 0x00, 0x00,
 		   0x00, 0x00 };
 
+	if (cmd->msg_len > sizeof(b) - 4)
+		return -EINVAL;
+
 	memcpy(&b[4], cmd->msg, cmd->msg_len);
 
 	state->config->send_command(fe, 0x72,
-- 
2.1.0