From: Andrew Dunstan <andrew@dunslane.net>
To: Tom Lane <tgl@sss.pgh.pa.us>
To: pgsql-hackers@lists.postgresql.org
Subject: Re: Residual cleanups for tied objects in PL/Perl
Date: Sun, 16 Aug 2026 14:47:47 -0400
Message-ID: <7e5de9c1-e2fe-44d2-9df3-670c6678e52b@dunslane.net> (raw)
In-Reply-To: <569769.1786901901@sss.pgh.pa.us>
References: <569769.1786901901@sss.pgh.pa.us>
On 2026-08-16 Su 1:38 PM, Tom Lane wrote:
> The attached patch fixes a null pointer dereference case in
> hstore_plperl, and an infinite-loop case in plperl itself.
> These were left out of the recent plperl security patch because
> they are not security matters according to our current rules;
> but they are certainly bugs that ought to be fixed.
>
> The test cases I have that reach these bugs require Perl "Tie"
> modules that aren't present in common Perl installations,
> so I'm not planning on trying to construct regression test
> entries for them. But I've attached two SQL scripts that
> cause failures without the patch.
Which modules?
>
> One interesting point is that Claude Opus, which constructed
> these test cases, seemed to think that we ought to be able
> to read out the values assigned to the tied array or hash.
> But what the repaired code actually produces is SQL NULLs.
> AFAICT we are getting Perl "undef" values out of hv_iternext
> or av_fetch, so it's hard to see how we could do any better.
At first glance I'm inclined to agree with Opus.
>
> I think what is going on here is that the test functions are
> failing to install enough infrastructure for the tied object
> to produce any output, but maybe someone who knows more Perl
> than me can correct that guess.
>
>
I wonder if it's conflicting with our opcode restrictions. I'll play
around a bit with it.
cheers
andrew
--
Andrew Dunstan
EDB: https://www.enterprisedb.com
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To: pgsql-hackers@postgresql.org
Cc: andrew@dunslane.net, tgl@sss.pgh.pa.us, pgsql-hackers@lists.postgresql.org
Subject: Re: Residual cleanups for tied objects in PL/Perl
In-Reply-To: <7e5de9c1-e2fe-44d2-9df3-670c6678e52b@dunslane.net>
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