Re: [BUG v13] Crash with event trigger in extension

Alvaro Herrera <alvherre@2ndquadrant.com>

From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: Jehan-Guillaume de Rorthais <jgdr@dalibo.com>
Cc: pgsql-bugs@lists.postgresql.org
Date: 2020-09-02T17:53:28Z
Lists: pgsql-bugs
On 2020-Sep-02, Jehan-Guillaume de Rorthais wrote:

> Hi,
> 
> Philippe Beaudoin reported to me a crash he was able to reproduce with some
> extension update script. Please, find in attachment a script that triggers it.
> Just edit the three first vars to point to a temporary installation and
> instance.
> 
> Some git bisect shows the bug was introduced by b5810de3f4, where
> multi-statement query strings are using different short memory contexts.

Good find.

I think we should turn your case into a proper TAP test so that we can
incorporate it, for coverage -- the lines you patch do appear covered,
but obviously not in these specific conditions.  I'm just not very sure
*where* to add it; maybe src/test/modules/test_extensions is the place
to have it, though that one doesn't have TAP tests currently.  An easy
addition, though.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services



Commits

  1. Fix use-after-free bug with event triggers and ALTER TABLE.

  2. Fix use-after-free bug with event triggers in an extension script