Horton

Re: Major Version Upgrade failure due to orphan roles entries in catalog

Virender Singla <virender.cse@gmail.com>

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From: Virender Singla <virender.cse@gmail.com>
To: Laurenz Albe <laurenz.albe@cybertec.at>
Cc: pgsql-bugs@lists.postgresql.org, Aniket Jha <aniketkumarj@gmail.com>
Date: 2025-02-13T09:51:18Z
Lists: pgsql-bugs

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Avoid race condition between "GRANT role" and "DROP ROLE".

  2. Fix pg_dumpall to cope with dangling OIDs in pg_auth_members.

  3. Ensure that pg_auth_members.grantor is always valid.

BTW a similar variant has been fixed in PG 16 but does not fix the above
case.

create role dropped_group;
create role member;
begin;
grant dropped_group to member;
OTHER SESSION: drop role dropped_group;
BACK IN ORIGINAL SESSION:
commit;




On Tue, Feb 11, 2025 at 7:50 PM Laurenz Albe <laurenz.albe@cybertec.at>
wrote:

> On Tue, 2025-02-11 at 15:32 +0530, Virender Singla wrote:
> > We have identified an issue causing upgrade failures. The following
> steps detail how to reproduce the issue:
> >
> > Create an orphan role entry
> >
> > /* Postgres version:: PostgreSQL 16.6 */
> > /* The same can be reproduced in version 17 as well */
> >
> > create role my_group;
> > create role dropped_member;
> > begin;
> > grant my_group to dropped_member;
> > OTHER SESSION: drop role dropped_member;
> > BACK IN ORIGINAL SESSION:
> > commit;
> >
> > Upgrade to Postgres v17
> >
> > And the upgrade fails with an error :
> >
> > GRANT "my_group" TO "" WITH INHERIT TRUE GRANTED BY "postgres";
> > ERROR: zero-length delimited identifier at or near """"
> >
> > The issue seems to be coming from pg_dumpall for building grants during
> pg_upgrade.
> >
> >
> https://github.com/postgres/postgres/blob/master/src/bin/pg_dump/pg_dumpall.c#L992
>
> I agree that that is a bug.
>
> I guess the GRANT statement should put a FOR KEY SHARE lock on the
> pg_authid row
> for "dropped_member", similar to what we do for foreign keys.
>
> Yours,
> Laurenz Albe
>
> --
>
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