[PATCH 3.16.y-ckt 061/165] USB: serial: fix tty-device error handling at probe

[Luis Henriques]

3.16.7-ckt9 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Johan Hovold <johan at kernel.org>

commit ca4383a3947a83286bc9b9c598a1f55e867871d7 upstream.

Add missing error handling when registering the tty device at port
probe. This avoids trying to remove an uninitialised character device
when the port device is removed.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: Takashi Iwai <tiwai at suse.de>
Signed-off-by: Johan Hovold <johan at kernel.org>
Acked-by: Greg Kroah-Hartman <greg at kroah.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/usb/serial/bus.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/serial/bus.c b/drivers/usb/serial/bus.c
index 5d8d86666b90..6f91eb9ae81a 100644
--- a/drivers/usb/serial/bus.c
+++ b/drivers/usb/serial/bus.c
@@ -51,6 +51,7 @@ static int usb_serial_device_probe(struct device *dev)
 {
 	struct usb_serial_driver *driver;
 	struct usb_serial_port *port;
+	struct device *tty_dev;
 	int retval = 0;
 	int minor;
 
@@ -80,7 +81,15 @@ static int usb_serial_device_probe(struct device *dev)
 	}
 
 	minor = port->minor;
-	tty_register_device(usb_serial_tty_driver, minor, dev);
+	tty_dev = tty_register_device(usb_serial_tty_driver, minor, dev);
+	if (IS_ERR(tty_dev)) {
+		retval = PTR_ERR(tty_dev);
+		device_remove_file(dev, &dev_attr_port_number);
+		if (driver->port_remove)
+			driver->port_remove(port);
+		goto exit_with_autopm;
+	}
+
 	dev_info(&port->serial->dev->dev,
 		 "%s converter now attached to ttyUSB%d\n",
 		 driver->description, minor);