USB: serial: spcp8x5: fix NULL-deref at open

Fix NULL-pointer dereference in open() should the device lack the
expected endpoints:

Unable to handle kernel NULL pointer dereference at virtual address 00000030
...
PC is at spcp8x5_open+0x30/0xd0 [spcp8x5]

Fixes: 619a6f1d1423 ("USB: add usb-serial spcp8x5 driver")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>

diff --git a/drivers/usb/serial/spcp8x5.c b/drivers/usb/serial/spcp8x5.c
index ef0dbf0..475e6c3 100644 (file)
--- a/drivers/usb/serial/spcp8x5.c
+++ b/drivers/usb/serial/spcp8x5.c
@@ -154,6 +154,19 @@ static int spcp8x5_probe(struct usb_serial *serial,
        return 0;
 }
 
+static int spcp8x5_attach(struct usb_serial *serial)
+{
+       unsigned char num_ports = serial->num_ports;
+
+       if (serial->num_bulk_in < num_ports ||
+                       serial->num_bulk_out < num_ports) {
+               dev_err(&serial->interface->dev, "missing endpoints\n");
+               return -ENODEV;
+       }
+
+       return 0;
+}
+
 static int spcp8x5_port_probe(struct usb_serial_port *port)
 {
        const struct usb_device_id *id = usb_get_serial_data(port->serial);
@@ -477,6 +490,7 @@ static struct usb_serial_driver spcp8x5_device = {
        .tiocmget               = spcp8x5_tiocmget,
        .tiocmset               = spcp8x5_tiocmset,
        .probe                  = spcp8x5_probe,
+       .attach                 = spcp8x5_attach,
        .port_probe             = spcp8x5_port_probe,
        .port_remove            = spcp8x5_port_remove,
 };