usb: fix reference leak in usb_new_device()

BugLink: https://bugs.launchpad.net/bugs/2097298

commit 0df11fa upstream.

When device_add(&udev->dev) succeeds and a later call fails,
usb_new_device() does not properly call device_del(). As comment of
device_add() says, 'if device_add() succeeds, you should call
device_del() when you want to get rid of it. If device_add() has not
succeeded, use only put_device() to drop the reference count'.

Found by code review.

Cc: stable <stable@kernel.org>
Fixes: 9f8b17e ("USB: make usbdevices export their device nodes instead of using a separate class")
Signed-off-by: Ma Ke <make_ruc2021@163.com>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/20241218071346.2973980-1-make_ruc2021@163.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Noah Wager <noah.wager@canonical.com>
Signed-off-by: Koichiro Den <koichiro.den@canonical.com>

Author: Ma Ke

drivers/usb/core/hub.c

@@ -2605,13 +2605,13 @@ int usb_new_device(struct usb_device *udev)
 		err = sysfs_create_link(&udev->dev.kobj,
 				&port_dev->dev.kobj, "port");
 		if (err)
-			goto fail;
+			goto out_del_dev;
 
 		err = sysfs_create_link(&port_dev->dev.kobj,
 				&udev->dev.kobj, "device");
 		if (err) {
 			sysfs_remove_link(&udev->dev.kobj, "port");
-			goto fail;
+			goto out_del_dev;
 		}
 
 		if (!test_and_set_bit(port1, hub->child_usage_bits))
@@ -2623,6 +2623,8 @@ int usb_new_device(struct usb_device *udev)
 	pm_runtime_put_sync_autosuspend(&udev->dev);
 	return err;
 
+out_del_dev:
+	device_del(&udev->dev);
 fail:
 	usb_set_device_state(udev, USB_STATE_NOTATTACHED);
 	pm_runtime_disable(&udev->dev);