[3.16.y-ckt stable] Patch "USB: serial: fix tty-device error handling at probe" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    USB: serial: fix tty-device error handling at probe

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt9.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From ca6ba06a9c1e7e09182c3bb21cb3b6823d49e215 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan at kernel.org>
Date: Wed, 18 Feb 2015 10:34:51 +0700
Subject: USB: serial: fix tty-device error handling at probe

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);