[media] ttusb-dec: buffer overflow in ioctl

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

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

1 files changed, 3 insertions, 0 deletions

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,