From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andrey Rachitskiy <pl0h0yp1@gmail.com>
cc: 1217816127@qq.com, pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #19601: Vuln45: Unbounded recursion via self-retying Perl
 scalar in bool_plperl's SvTRUE call causes backend
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Comments: In-reply-to Andrey Rachitskiy <pl0h0yp1@gmail.com>
	message dated "Tue, 04 Aug 2026 02:10:50 +0500"
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Date: Mon, 03 Aug 2026 18:01:50 -0400
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Andrey Rachitskiy <pl0h0yp1@gmail.com> writes:
> Thanks for the report.  I can reproduce the SIGSEGV on current master
> (with --with-perl).

I can't get excited about this.  A plperl user who wishes to cause
recursion to stack overflow can do so far more simply than what is
proposed here: just write an indefinitely-recursive Perl function
and call it.  That recursion will be totally inside libperl, so
we can do nothing about it.  The same holds for every other PL
that exposes a general-purpose programming language.

I certainly wouldn't add the amount of code you propose here to close
off just one route to that, even if I trusted the patch which I don't.
(It seems far too much in-bed with details of libperl's innards, and
hence likely to fail on other Perl versions than what you tested.)

			regards, tom lane