USB: serial: ftdi_sio: only allow valid event_char values
The "event_char" device attribute value, when written, is interpreted as
an enable bit in bit 8, and an "event character" in bits 7 to 0.
Return an error -EINVAL for out-of-range values. Use kstrtouint() to
parse the integer instead of the obsolete simple_strtoul().
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Johan Hovold <johan@kernel.org>
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index b774f9d..4032a67 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -1738,9 +1738,12 @@
struct usb_serial_port *port = to_usb_serial_port(dev);
struct ftdi_private *priv = usb_get_serial_port_data(port);
struct usb_device *udev = port->serial->dev;
- int v = simple_strtoul(valbuf, NULL, 10);
+ unsigned int v;
int rv;
+ if (kstrtouint(valbuf, 10, &v) || v >= 0x200)
+ return -EINVAL;
+
dev_dbg(&port->dev, "%s: setting event char = %i\n", __func__, v);
rv = usb_control_msg(udev,