usb: usbip: fix a refcount leak in stub_probe()

[ Upstream commit 9ec4cbf ]

usb_get_dev() is called in stub_device_alloc(). When stub_probe() fails
after that, usb_put_dev() needs to be called to release the reference.

Fix this by moving usb_put_dev() to sdev_free error path handling.

Find this by code review.

Fixes: 3ff6744 ("usbip: fix error handling in stub_probe()")
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
Link: https://lore.kernel.org/r/20220412020257.9767-1-hbh25y@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/usb/usbip/stub_dev.c

@@ -393,7 +393,6 @@ static int stub_probe(struct usb_device *udev)
 
 err_port:
 	dev_set_drvdata(&udev->dev, NULL);
-	usb_put_dev(udev);
 
 	/* we already have busid_priv, just lock busid_lock */
 	spin_lock(&busid_priv->busid_lock);
@@ -408,6 +407,7 @@ static int stub_probe(struct usb_device *udev)
 	put_busid_priv(busid_priv);
 
 sdev_free:
+	usb_put_dev(udev);
 	stub_device_free(sdev);
 
 	return rc;