Horton

Re: Converting contrib SQL functions to new style

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Noah Misch <noah@leadboat.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Date: 2021-04-14T18:03:56Z
Lists: pgsql-hackers 
Robert Haas <robertmhaas@gmail.com> writes:
> On Wed, Apr 14, 2021 at 1:41 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Could we hack things so that extension scripts are only allowed to
>> reference objects created (a) by the system, (b) earlier in the
>> same script, or (c) owned by one of the declared prerequisite
>> extensions?  Seems like that might provide a pretty bulletproof
>> defense against trojan-horse objects, though I'm not sure how much
>> of a pain it'd be to implement.

> That doesn't seem like a crazy idea, but the previous idea of having
> some magic syntax that means "the schema where extension FOO is" seems
> like it might be easier to implement and more generally useful.

I think that's definitely useful, but it's not a fix for the
reference-capture problem unless you care to assume that the other
extension's schema is free of trojan-horse objects.  So I'm thinking
that we really ought to pursue both ideas.

This may mean that squeezing these contrib changes into v14 is a lost
cause.  We certainly shouldn't try to do what I suggest above for
v14; but without it, these changes are just moving the security
issue to a different place rather than eradicating it completely.

			regards, tom lane

Commits

  1. Use @extschema:name@ notation in contrib transform modules.

  2. pg_freespacemap: Fix declaration of pg_freespace(regclass)

  3. contrib/pageinspect: Use SQL-standard function bodies.

  4. contrib/xml2: Use SQL-standard function bodies.

  5. contrib/citext: Use SQL-standard function bodies.

  6. contrib/earthdistance: Use SQL-standard function bodies.

  7. contrib/lo: Use SQL-standard function bodies

  8. xml2: Add tests for functions xpath_nodeset() and xpath_list()

  9. contrib/lo: Add test for function lo_oid()

  10. pg_freespacemap: Use SQL-standard function bodies

  11. Add @extschema:name@ and no_relocate options to extensions.

  12. Make contrib modules' installation scripts more secure.