Re: [PATCH] Add enable_copy_program GUC to control COPY PROGRAM

On Wed, Dec 03, 2025 at 11:35:07AM -0800, Jacob Champion wrote:
> Yeah, these conversations tend to get stuck right at this point.
> Restricting superuser so that it's somehow not superuser is a huge
> (intractable?) undertaking. Doing it a piece at a time doesn't make a
> lot of sense if we're not sure that an endpoint exists. But the
> ability to escape from the database into the system around it still
> seems like a legitimate concern.

Yeah, I have a feeling that we're going to continue to receive proposals in
this area. Perhaps a good first step is to start listing all the
functionality that crosses the OS/database user boundary. Then we might be
able to better approximate the effort required and whether we feel
comfortable maintaining such a boundary.

> A lot of work has been done recently to split apart these privileges
> into smaller roles. So what if we just didn't hand out superuser by
> default?
>
> Could initdb be made to instead give you a user with the power to
> manage almost all of the database (i.e. pg_maintain/pg_monitor), but
> without the power to touch anything outside it or execute arbitrary
> code? When you needed true superuser, you could still unlock it from
> the outside, and at that point it shouldn't be surprising that you can
> escape.

IIRC there's been some discussion about that over the years, including in
my old thread about compiling out untrusted languages [0].

[0] https://postgr.es/m/flat/20220520225619(dot)GA876272(at)nathanxps13

--
nathan