Drivers: hv: vmbus: fix possible memory leak in vmbus_device_register()

[ Upstream commit 25c94b0515 ]

If device_register() returns error in vmbus_device_register(),
the name allocated by dev_set_name() must be freed. As comment
of device_register() says, it should use put_device() to give
up the reference in the error path. So fix this by calling
put_device(), then the name can be freed in kobject_cleanup().

Fixes: 09d50ff8a2 ("Staging: hv: make the Hyper-V virtual bus code build")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20221119081135.1564691-3-yangyingliang@huawei.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/hv/vmbus_drv.c

@@ -2109,6 +2109,7 @@ int vmbus_device_register(struct hv_device *child_device_obj)
 	ret = device_register(&child_device_obj->device);
 	if (ret) {
 		pr_err("Unable to register child device\n");
+		put_device(&child_device_obj->device);
 		return ret;
 	}