This commit fixes failures with "tuple already updated by self" when
listing twice the same role and in a DROP ROLE query.
This is an oversight in 6566133c5f, that has introduced a two-phase
logic in DropRole() where dependencies of all the roles to drop are
removed in a first phase, with the roles themselves removed from
pg_authid in a second phase.
The code is simplified to not rely on a List of ObjectAddress built in
the first phase used to remove the pg_authid entries in the second
phase, switching to a list of OIDs. Duplicated OIDs can be simply
avoided in the first phase thanks to that. Using ObjectAddress was not
necessary for the roles as they are not used for anything specific to
dependency.c, building all the ObjectAddress in the List with
AuthIdRelationId as class ID.
In 15 and older versions, where a single phase is used, DROP ROLE with
duplicated role names would fail on "role \"blah\" does not exist" for
the second entry after the CCI() done by the first deletion. This is
not really incorrect, but it does not seem worth changing based on a
lack of complaints.
Reported-by: Alexander Lakhin
Reviewed-by: Tender Wang
Discussion: https://postgr.es/m/18310-1eb233c5908189c8@postgresql.org
Backpatch-through: 16
Mainly move some detail from errmsg to errdetail, remove explicit
mention of superuser where appropriate, since that is implied in most
permission checks, and make messages more uniform.
Author: Nathan Bossart <nathandbossart@gmail.com>
Discussion: https://www.postgresql.org/message-id/20230316234701.GA903298@nathanxps13
Previously, a CREATEROLE user without SUPERUSER could not alter
REPLICATION users in any way, and could not set the BYPASSRLS
attribute. However, they could manipulate the CREATEDB property
even if they themselves did not possess it.
With this change, a CREATEROLE user without SUPERUSER can set or
clear the REPLICATION, BYPASSRLS, or CREATEDB property on a new
role or a role that they have rights to manage if and only if
that property is set for their own role.
This implements the standard idea that you can't give permissions
you don't have (but you can give the ones you do have). We might
in the future want to provide more powerful ways to constrain
what a CREATEROLE user can do - for example, to limit whether
CONNECTION LIMIT can be set or the values to which it can be set -
but that is left as future work.
Patch by me, reviewed by Nathan Bossart, Tushar Ahuja, and Neha
Sharma.
Discussion: http://postgr.es/m/CA+TgmobX=LHg_J5aT=0pi9gJy=JdtrUVGAu0zhr-i5v5nNbJDg@mail.gmail.com
Commits cf5eb37c5 and e5b8a4c09 each created a new role that they
forgot to remove again. This breaks the use-case of running "make
installcheck" more than once, and it's also against project policy
because it'd be quite unfriendly behavior if one were running
"make installcheck" against a non-throwaway installation.
Can be set to the empty string, or to either or both of "set" or
"inherit". If set to a non-empty value, a non-superuser who creates
a role (necessarily by relying up the CREATEROLE privilege) will
grant that role back to themselves with the specified options.
This isn't a security feature, because the grant that this feature
triggers can also be performed explicitly. Instead, it's a user experience
feature. A superuser would necessarily inherit the privileges of any
created role and be able to access all such roles via SET ROLE;
with this patch, you can configure createrole_self_grant = 'set, inherit'
to provide a similar experience for a user who has CREATEROLE but not
SUPERUSER.
Discussion: https://postgr.es/m/CA+TgmobN59ct+Emmz6ig1Nua2Q-_o=r6DSD98KfU53kctq_kQw@mail.gmail.com
Previously, CREATEROLE users were permitted to make nearly arbitrary
changes to roles that they didn't create, with certain exceptions,
particularly superuser roles. Instead, allow CREATEROLE users to make such
changes to roles for which they possess ADMIN OPTION, and to
grant membership only in roles for which they possess ADMIN OPTION.
When a CREATEROLE user who is not a superuser creates a role, grant
ADMIN OPTION on the newly-created role to the creator, so that they
can administer roles they create or for which they have been given
privileges.
With these changes, CREATEROLE users still have very significant
powers that unprivileged users do not receive: they can alter, rename,
drop, comment on, change the password for, and change security labels
on roles. However, they can now do these things only for roles for
which they possess appropriate privileges, rather than all
non-superuser roles; moreover, they cannot grant a role such as
pg_execute_server_program unless they themselves possess it.
Patch by me, reviewed by Mark Dilger.
Discussion: https://postgr.es/m/CA+TgmobN59ct+Emmz6ig1Nua2Q-_o=r6DSD98KfU53kctq_kQw@mail.gmail.com
Previously, membership of role A in role B could be recorded in the
catalog tables only once. This meant that a new grant of role A to
role B would overwrite the previous grant. For other object types, a
new grant of permission on an object - in this case role A - exists
along side the existing grant provided that the grantor is different.
Either grant can be revoked independently of the other, and
permissions remain so long as at least one grant remains. Make role
grants work similarly.
Previously, when granting membership in a role, the superuser could
specify any role whatsoever as the grantor, but for other object types,
the grantor of record must be either the owner of the object, or a
role that currently has privileges to perform a similar GRANT.
Implement the same scheme for role grants, treating the bootstrap
superuser as the role owner since roles do not have owners. This means
that attempting to revoke a grant, or admin option on a grant, can now
fail if there are dependent privileges, and that CASCADE can be used
to revoke these. It also means that you can't grant ADMIN OPTION on
a role back to a user who granted it directly or indirectly to you,
similar to how you can't give WITH GRANT OPTION on a privilege back
to a role which granted it directly or indirectly to you.
Previously, only the superuser could specify GRANTED BY with a user
other than the current user. Relax that rule to allow the grantor
to be any role whose privileges the current user posseses. This
doesn't improve compatibility with what we do for other object types,
where support for GRANTED BY is entirely vestigial, but it makes this
feature more usable and seems to make sense to change at the same time
we're changing related behaviors.
Along the way, fix "ALTER GROUP group_name ADD USER user_name" to
require the same privileges as "GRANT group_name TO user_name".
Previously, CREATEROLE privileges were sufficient for either, but
only the former form was permissible with ADMIN OPTION on the role.
Now, either CREATEROLE or ADMIN OPTION on the role suffices for
either spelling.
Patch by me, reviewed by Stephen Frost.
Discussion: http://postgr.es/m/CA+TgmoaFr-RZeQ+WoQ5nKPv97oT9+aDgK_a5+qWHSgbDsMp1Vg@mail.gmail.com
Previously, "GRANT foo TO bar" or "GRANT foo TO bar GRANTED BY baz"
would record the OID of the grantor in pg_auth_members.grantor, but
that role could later be dropped without modifying or removing the
pg_auth_members record. That's not great, because we typically try
to avoid dangling references in catalog data.
Now, a role grant depends on the grantor, and the grantor can't be
dropped without removing the grant or changing the grantor. "DROP
OWNED BY" will remove the grant, just as it does for other kinds of
privileges. "REASSIGN OWNED BY" will not, again just like what we do
in other cases involving privileges.
pg_auth_members now has an OID column, because that is needed in order
for dependencies to work. It also now has an index on the grantor
column, because otherwise dropping a role would require a sequential
scan of the entire table to see whether the role's OID is in use as
a grantor. That probably wouldn't be too large a problem in practice,
but it seems better to have an index just in case.
A follow-on patch is planned with the goal of more thoroughly
rationalizing the behavior of role grants. This patch is just trying
to do enough to make sure that the data we store in the catalogs is at
some basic level valid.
Patch by me, reviewed by Stephen Frost
Discussion: http://postgr.es/m/CA+TgmoaFr-RZeQ+WoQ5nKPv97oT9+aDgK_a5+qWHSgbDsMp1Vg@mail.gmail.com
Michael Paquier
Peter Eisentraut
Robert Haas
Tom Lane
Andrew Dunstan