diff --git a/drivers/media/usb/dvb-usb/digitv.c b/drivers/media/usb/dvb-usb/digitv.c
index 4284f6984dc1ffe14698b6fcdc42aad8cf69bf32..475a3c0cdee7f88a9630f337cd9d0aaf59f2e177 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);