drivers: dio: fix possible memory leak in dio_init()

[ Upstream commit e63e9939 ]

If device_register() returns error, the 'dev' and name needs be
freed. Add a release function, and then call put_device() in the
error path, so the name is freed in kobject_cleanup() and to the
'dev' is freed in release function.

Fixes: 2e4c77be ("m68k: dio - Kill warn_unused_result warnings")
Fixes: 1fa5ae85 ("driver core: get rid of struct device's bus_id string array")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20221109064036.1835346-1-yangyingliang@huawei.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/dio/dio.c

@@ -110,6 +110,12 @@ static char dio_no_name[] = { 0 };
 
 #endif /* CONFIG_DIO_CONSTANTS */
 
+static void dio_dev_release(struct device *dev)
+{
+	struct dio_dev *ddev = container_of(dev, typeof(struct dio_dev), dev);
+	kfree(ddev);
+}
+
 int __init dio_find(int deviceid)
 {
 	/* Called to find a DIO device before the full bus scan has run.
@@ -222,6 +228,7 @@ static int __init dio_init(void)
 		dev->bus = &dio_bus;
 		dev->dev.parent = &dio_bus.dev;
 		dev->dev.bus = &dio_bus_type;
+		dev->dev.release = dio_dev_release;
 		dev->scode = scode;
 		dev->resource.start = pa;
 		dev->resource.end = pa + DIO_SIZE(scode, va);
@@ -249,6 +256,7 @@ static int __init dio_init(void)
 		if (error) {
 			pr_err("DIO: Error registering device %s\n",
 			       dev->name);
+			put_device(&dev->dev);
 			continue;
 		}
 		error = dio_create_sysfs_dev_files(dev);