Re: check_circularity does not prevent from creating circular grants

Hi,

On Mon, 10 Aug 2026 at 15:13, Andrey Borodin <x4mmm(at)yandex-team(dot)ru> wrote:

>
>
> > On 10 Aug 2026, at 12:03, Kirill Reshke <reshkekirill(at)gmail(dot)com> wrote:
> >
> > I discovered a sequence of ddl which creates grant configuration,
> > unrestorable from pg_dump-pg_restore.
>
> The diagnosis looks right, but I think the proposed fix is too broad.
>
> Suppose the owner grants an option directly to role A, role B is a member
> of A, and A grants the option to B. This is not circular: after revoking
> B's membership in A, the grant from A remains valid. Changing the loop to
> has_privs_of_role(B, A) would remove A's independently held option and
> reject this case.
>
> select_best_grantor() uses aclmask_direct() instead of aclmask(). WDYT
> about
> this route?
>

There was some prior discussion around this area on [0].

Not sure if it's the same block, but just adding reference.

Regards,
Ayush

[0]
https://www.postgresql.org/message-id/CAJTYsWUvyQchDAA6y2a9YdLcApG%3DccArpsbr77FeNZyx40bnmQ%40mail.gmail.com