Hi,
On 15.02.2024 20:07, Dominique Devienne wrote:
And now with V16.1 ===========================
ddevienne=> create role zowner nologin createrole; -- owner of app's
schemas and manager of related roles
CREATE ROLE
ddevienne=> set role zowner;
ERROR: permission denied to set role "zowner"
ddevienne=> select roleid::regrole::text, member::regrole::text,
grantor::regrole::text, admin_option, set_option, inherit_option from
pg_auth_members where roleid::regrole::text like 'z%' or
member::regrole::text like 'z%';
roleid | member | grantor | admin_option | set_option |
inherit_option
--------+-----------+----------+--------------+------------+----------------
zowner | ddevienne | postgres | t | f | f
(1 row)
You can use new psql command \drg for this query.
(2 rows)
ddevienne=> set role zowner;
SET
ddevienne=> create role zadmin nologin noinherit in role zowner; --
means to become zowner explicitly
ERROR: permission denied to grant role "zowner"
DETAIL: Only roles with the ADMIN option on role "zowner" may grant
this role.
ddevienne=>
So first surprise in V16. Despite having admin_option, from being the
creator of the zowner role, I can't SET ROLE to it. I have to
explicitly add the SET privilege.
Yes, but you can automate it with setting new parameter createrole_self_grant.
postgres@demo=# create role ddevienne login createrole;
CREATE ROLE
postgres@demo=# alter role ddevienne set createrole_self_grant = 'INHERIT, SET';
ALTER ROLE
postgres@demo=# \c - ddevienne
You are now connected to database "demo" as user "ddevienne".
ddevienne@demo=> create role zowner nologin createrole;
CREATE ROLE
ddevienne@demo=> \drg ddevienne
List of role grants
Role name | Member of | Options | Grantor
-----------+-----------+--------------+-----------
ddevienne | zowner | INHERIT, SET | ddevienne
ddevienne | zowner | ADMIN | postgres
(2 rows)
ddevienne@demo=> set role zowner;
SET
And then, when ddevienne SET ROLE's to zowner, and tries to create
zadmin *and* add it at the same time as a member of zowner (the
current_role), it fails.
So it looks like, despite ddevienne having admin_option on zowner,
because it is on a "different line" than the set_option, it still
cannot add members in zowner???
Behaviorchanged <https://github.com/postgres/postgres/commit/79de9842> for
security reasons in v15. From Release Notes:
> Remove the default ADMIN OPTION privilege a login role has on its own
role membership (Robert Haas)
> Previously, a login role could add/remove members of its own role, even
without ADMIN OPTION privilege.
Zowner can create zadmin, but no way to grant membership in itself.
What you can do is create a role zadmin by ddevienne:
ddevienne@demo=> reset role;
RESET
ddevienne@demo=> create role zadmin nologin noinherit;
CREATE ROLE
ddevienne@demo=> grant zowner to zadmin with inherit true, set true;
GRANT ROLE
ddevienne@demo=> \drg zadmin
List of role grants
Role name | Member of | Options | Grantor
-----------+-----------+--------------+-----------
zadmin | zowner | INHERIT, SET | ddevienne
(1 row)
--
Pavel Luzanov
Postgres Professional:https://postgrespro.com
