Re: [PATCH] Fix memory corruption in pg_shdepend.c

On 2021-Oct-20, Michael Paquier wrote:

> On Wed, Oct 20, 2021 at 01:01:31PM +0300, Aleksander Alekseev wrote:
> > I checked the rest of the PostgreSQL code and apparently, it should
> > have been tts_values[Anum_pg_shdepend_FOO - 1].
> >
> > The patch is attached. The problem was first reported offlist by Sven
> > Klemm. Investigated and fixed by me.
>
> Yes, that's indeed a one-off bug when copying shared dependencies of a
> template database to the new one. This is new as of e3931d0, so I'll
> take care of that and double-check the area while on.

Ouch ... this means that pg_shdepends contents are broken for databases
created with 14.0? hmm ... yes.

alvherre=# create role rol;
CREATE ROLE
alvherre=# create table blarg() ;
CREATE TABLE
alvherre=# alter table blarg owner to rol;
ALTER TABLE
alvherre=# create database bar template alvherre;
CREATE DATABASE
alvherre=# \c bar
Ahora está conectado a la base de datos «bar» con el usuario «alvherre».
bar=# select * from pg_shdepend;
dbid | classid | objid | objsubid | refclassid | refobjid | deptype
-------+---------+-------+----------+------------+----------+---------
0 | 0 | 0 | 0 | 1260 | 10 | p
0 | 0 | 0 | 0 | 1260 | 6171 | p
0 | 0 | 0 | 0 | 1260 | 6181 | p
0 | 0 | 0 | 0 | 1260 | 6182 | p
0 | 0 | 0 | 0 | 1260 | 3373 | p
0 | 0 | 0 | 0 | 1260 | 3374 | p
0 | 0 | 0 | 0 | 1260 | 3375 | p
0 | 0 | 0 | 0 | 1260 | 3377 | p
0 | 0 | 0 | 0 | 1260 | 4569 | p
0 | 0 | 0 | 0 | 1260 | 4570 | p
0 | 0 | 0 | 0 | 1260 | 4571 | p
0 | 0 | 0 | 0 | 1260 | 4200 | p
12975 | 1259 | 37686 | 0 | 1260 | 37685 | o
| 37689 | 1259 | 37686 | 0 | 1260 | 5
(14 filas)

bar=# select 37689::regclass;
regclass
----------
37689
(1 fila)

--
Álvaro Herrera PostgreSQL Developer — https://www.EnterpriseDB.com/