Horton

Re: Segmentation fault during update inside ExecBRUpdateTriggers

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Thomas Munro <thomas.munro@gmail.com>, Piotr Gabriel Kosinski <pg.kosinski@gmail.com>, PostgreSQL mailing lists <pgsql-bugs@lists.postgresql.org>
Date: 2019-08-15T23:09:37Z
Lists: pgsql-bugs 
On 2019-08-15 18:39:24 -0400, Tom Lane wrote:
> Thomas Munro <thomas.munro@gmail.com> writes:
> > Right, this happens on REL_11_STABLE but not on master (which rewrote
> > the relevant code quite a bit in the "slotification" project).
> 
> We should probably trace back why it doesn't happen before v11.
> I have a vague memory of having touched this code a year or two
> back, so likely this is my fault, but I wonder why it doesn't
> fail before.

There's

commit 25b692568f429436f89ff203c1413e9670d0ad67
Author: Tom Lane <tgl@sss.pgh.pa.us>
Date:   2018-02-27 13:27:38 -0500

    Prevent dangling-pointer access when update trigger returns old tuple.

But that shouldn't itself have caused it. But the referenced 4b93f5799
might have.

Greetings,

Andres Freund

Commits

  1. Prevent possible double-free when update trigger returns old tuple.

  2. Prevent dangling-pointer access when update trigger returns old tuple.