powercap: call put_device() on an error path in powercap_register_control_type()

JIRA: https://issues.redhat.com/browse/RHEL-47408

commit 93c66fb
Author: Joe Hattori <[email protected]>
Date:   Fri Jan 10 10:05:54 2025 +0900

    powercap: call put_device() on an error path in powercap_register_control_type()

    powercap_register_control_type() calls device_register(), but does not
    release the refcount of the device when it fails.

    Call put_device() before returning an error to balance the refcount.

    Since the kfree(control_type) will be done by powercap_release(), remove
    the lines in powercap_register_control_type() before returning the error.

    This bug was found by an experimental verifier that I am developing.

    Signed-off-by: Joe Hattori <[email protected]>
    Link: https://patch.msgid.link/[email protected]
    [ rjw: Changelog edits ]
    Signed-off-by: Rafael J. Wysocki <[email protected]>

Signed-off-by: David Arcari <[email protected]>

Author: darcari

drivers/powercap/powercap_sys.c

@@ -627,8 +627,7 @@ struct powercap_control_type *powercap_register_control_type(
 	dev_set_name(&control_type->dev, "%s", name);
 	result = device_register(&control_type->dev);
 	if (result) {
-		if (control_type->allocated)
-			kfree(control_type);
+		put_device(&control_type->dev);
 		return ERR_PTR(result);
 	}
 	idr_init(&control_type->idr);