Re: First draft of the PG 15 release notes - Mailing list pgsql-hackers

On Tue, Jul 05, 2022 at 04:35:32PM -0400, Bruce Momjian wrote:
> On Tue, Jul  5, 2022 at 12:53:49PM -0700, Noah Misch wrote:
> > On Tue, Jul 05, 2022 at 02:35:39PM -0400, Bruce Momjian wrote:
> > > On Fri, Jul  1, 2022 at 06:21:28PM -0700, Noah Misch wrote:
> > > > Here's what I've been trying to ask: what do you think of linking to
> > > > https://www.postgresql.org/docs/devel/ddl-schemas.html#DDL-SCHEMAS-PATTERNS
> > > > here?  The release note text is still vague, and the docs have extensive
> > > > coverage of the topic.  The notes can just link to that extensive coverage.
> > > 
> > > Sure. how is this patch?
> > 
> > > --- a/doc/src/sgml/release-15.sgml
> > > +++ b/doc/src/sgml/release-15.sgml
> > > @@ -63,11 +63,12 @@ Author: Noah Misch <noah@leadboat.com>
> > >        permissions on the <literal>public</literal> schema has not
> > >        been changed.  Databases restored from previous Postgres releases
> > >        will be restored with their current permissions.  Users wishing
> > > -      to have the former permissions will need to grant
> > > +      to have the former more-open permissions will need to grant
> > >        <literal>CREATE</literal> permission for <literal>PUBLIC</literal>
> > >        on the <literal>public</literal> schema; this change can be made
> > >        on <literal>template1</literal> to cause all new databases
> > > -      to have these permissions.
> > > +      to have these permissions.  This change was made to increase
> > > +      security;  see <xref linkend="ddl-schemas-patterns"/>.
> > >       </para>
> > >      </listitem>
> > 
> > I think this still puts undue weight on single-user systems moving back to the
> > old default.  The linked documentation does say how to get back to v14
> > permissions (and disclaims security if you do so), so let's not mention it
> > here.  The attached is how I would write it.  I also reworked the "Databases
> > restored from previous ..." sentence, since its statement is also true of
> > databases restored v15-to-v15 (no "previous" release involved).  I also moved
> > the bit about USAGE to end, since it's just emphasizing what the reader should
> > already assume.  Any concerns?
> 
> I see where you are going --- to talk about how to convert upgraded
> clusters to secure clusters, rather than how to revert to the previous
> behavior.  I assumed that the most common question would be how to get
> the previous behavior, rather than how to get the new behavior in
> upgraded clusters.  However, I am fine with what you think is best.

Since having too-permissive ACLs is usually symptom-free, I share your
forecast about the more-common question.  Expect questions on mailing lists,
stackoverflow, etc.  The right way to answer those questions is roughly this:

    > On PostgreSQL 15, my application gets "permission denied for schema
    > public".  What should I do?

    You have a choice to make.  The best selection depends on the security
    needs of your database.  See
    https://www.postgresql.org/docs/devel/ddl-schemas.html#DDL-SCHEMAS-PATTERNS
    for a guide to making that choice.

Recommending GRANT to that two-sentence question would be negligent.  One
should know a database's lack of security needs before recommending GRANT.
This is a key opportunity to have more users make the right decision while
their attention is on the topic.

> My only stylistic suggestion would be to remove "a" from "a
> <literal>REVOKE</literal>".

I'll plan to push with that change.