Update federated table and column privileges

create database my_user;

create user 'my'@'x.x.x.x' identified by '1qaz2wsx';

use my_user;

CREATE TABLE `users` (

  `id` int(6) NOT NULL AUTO_INCREMENT,

  `name` varchar(50) DEFAULT NULL,

  `password` varchar(50) DEFAULT NULL,

  PRIMARY KEY (`id`),

  UNIQUE KEY `name` (`name`)

);

GRANT INSERT, SELECT (`id`, `name`, `password`), UPDATE (`password`) ON `my_user`.`users` TO `my`@`x.x.x.x`;

create database prod_db;

create user 'prod_user' identified by '2wsx3edc';

GRANT ALL PRIVILEGES ON prod_db.* TO 'prod_user' WITH GRANT OPTION;

CREATE TABLE `prod_f` (

  `id` int(6) NOT NULL AUTO_INCREMENT,

  `name` varchar(50) DEFAULT NULL,

  `password` varchar(50) DEFAULT NULL,

  PRIMARY KEY (`id`),

  UNIQUE KEY `name` (`name`)

) ENGINE=FEDERATED DEFAULT CHARSET=utf8 CONNECTION='mysql://my:1qaz2wsx@a.a.a.a:3306/my_user/users';

insert into prod_f (name,password) values ('test','123');

select * from prod_f\G

      id: 1

    name: test

password: 123

UPDATE prod_f SET password='123456' WHERE name='test';

ERROR 1296 (HY000): Got error 10000 'Error on remote system: 1143: UPDATE command denied to user 'my'@'x.x.x.x' for column 'id' in table 'users'' from FEDERATED