[#MDEV-19088] SUPER is not required for ALTER FUNCTION when log_bin_trust_function_creators=OFF and log

The documentation says that SUPER should be required for ALTER FUNCTION when log_bin_trust_function_creators=OFF and log_bin=ON:

But a quick test shows that this is not the case.

For example, if I create a function as a user with SUPER:

CREATE FUNCTION trust_me(x INT)

RETURNS INT

DETERMINISTIC

READS SQL DATA

   RETURN (x);

And then create a user with the ALTER ROUTINE privilege, but without SUPER:

CREATE USER 'function_test'@localhost IDENTIFIED BY 'password';

GRANT ALTER ROUTINE ON db1.* TO 'function_test'@localhost;

And then ensure that both log_bin_trust_function_creators=OFF and log_bin=ON:

MariaDB [db1]> SHOW GLOBAL VARIABLES WHERE Variable_name IN('log_bin_trust_function_creators', 'log_bin');

+---------------------------------+-------+

| Variable_name                   | Value |

+---------------------------------+-------+

| log_bin                         | ON    |

| log_bin_trust_function_creators | OFF   |

+---------------------------------+-------+

2 rows in set (0.01 sec)

You would think that this user would not be able to alter the function. But a test shows that the user can:

MariaDB [db1]> ALTER FUNCTION trust_me NO SQL;

Query OK, 0 rows affected (0.00 sec)

MariaDB [db1]> SHOW GRANTS;

+----------------------------------------------------------------------------------------------------------------------+

| Grants for function_test@localhost                                                                                   |

+----------------------------------------------------------------------------------------------------------------------+

| GRANT USAGE ON *.* TO 'function_test'@'localhost' IDENTIFIED BY PASSWORD '*2470C0C06DEE42FD1618BB99005ADCA2EC9D1E19' |

| GRANT ALTER ROUTINE ON `db1`.* TO 'function_test'@'localhost'                                                        |

+----------------------------------------------------------------------------------------------------------------------+

2 rows in set (0.00 sec)

Code analysis shows that the Sp_handler::sp_update_routine does not check SUPER_ACL like Sp_handler::sp_create_routine does.

sp_create_routine check:

sp_update_routine check:

[MDEV-19088] SUPER is not required for ALTER FUNCTION when log_bin_trust_function_creators=OFF and log_bin=ON Created: 2019-03-29 Updated: 2023-12-04
Status:	Open
Project:	MariaDB Server
Component/s:	Authentication and Privilege System, Data Definition - Procedure, PL/SQL, Stored routines
Affects Version/s:	10.1.38
Fix Version/s:	10.4