diff --git a/drivers/usb/serial/mos7840.c b/drivers/usb/serial/mos7840.c
index 2cfe2451ed97..04bef4bebc4a 100644
--- a/drivers/usb/serial/mos7840.c
+++ b/drivers/usb/serial/mos7840.c
@@ -283,12 +283,19 @@ static int mos7840_get_reg_sync(struct usb_serial_port *port, __u16 reg,
 {
 	struct usb_device *dev = port->serial->dev;
 	int ret = 0;
+	u8 *buf;
+
+	buf = kmalloc(VENDOR_READ_LENGTH, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
 
 	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), MCS_RDREQ,
-			      MCS_RD_RTYPE, 0, reg, val, VENDOR_READ_LENGTH,
+			      MCS_RD_RTYPE, 0, reg, buf, VENDOR_READ_LENGTH,
 			      MOS_WDR_TIMEOUT);
+	*val = buf[0];
 	dbg("mos7840_get_reg_sync offset is %x, return val %x", reg, *val);
-	*val = (*val) & 0x00ff;
+
+	kfree(buf);
 	return ret;
 }
 
@@ -341,6 +348,11 @@ static int mos7840_get_uart_reg(struct usb_serial_port *port, __u16 reg,
 	struct usb_device *dev = port->serial->dev;
 	int ret = 0;
 	__u16 Wval;
+	u8 *buf;
+
+	buf = kmalloc(VENDOR_READ_LENGTH, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
 
 	/* dbg("application number is %4x",
 	    (((__u16)port->number - (__u16)(port->serial->minor))+1)<<8); */
@@ -364,9 +376,11 @@ static int mos7840_get_uart_reg(struct usb_serial_port *port, __u16 reg,
 		}
 	}
 	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), MCS_RDREQ,
-			      MCS_RD_RTYPE, Wval, reg, val, VENDOR_READ_LENGTH,
+			      MCS_RD_RTYPE, Wval, reg, buf, VENDOR_READ_LENGTH,
 			      MOS_WDR_TIMEOUT);
-	*val = (*val) & 0x00ff;
+	*val = buf[0];
+
+	kfree(buf);
 	return ret;
 }