USB: rio500: fix memory leak in close after disconnect

BugLink: https://bugs.launchpad.net/bugs/1832661

commit e0feb734 upstream.

If a disconnected device is closed, rio_close() must free
the buffers.
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

drivers/usb/misc/rio500.c

@@ -103,9 +103,22 @@ static int close_rio(struct inode *inode, struct file *file)
 {
 	struct rio_usb_data *rio = &rio_instance;
 
-	rio->isopen = 0;
+	/* against disconnect() */
+	mutex_lock(&rio500_mutex);
+	mutex_lock(&(rio->lock));
 
-	dev_info(&rio->rio_dev->dev, "Rio closed.\n");
+	rio->isopen = 0;
+	if (!rio->present) {
+		/* cleanup has been delayed */
+		kfree(rio->ibuf);
+		kfree(rio->obuf);
+		rio->ibuf = NULL;
+		rio->obuf = NULL;
+	} else {
+		dev_info(&rio->rio_dev->dev, "Rio closed.\n");
+	}
+	mutex_unlock(&(rio->lock));
+	mutex_unlock(&rio500_mutex);
 	return 0;
 }