From: Tom Lane <tgl@sss.pgh.pa.us>
To: =?utf-8?Q?Dagfinn_Ilmari_Manns=C3=A5ker?= <ilmari@ilmari.org>
cc: Nathan Bossart <nathandbossart@gmail.com>,
        Kyotaro Horiguchi <horikyota.ntt@gmail.com>, michael@paquier.xyz,
        gurjeet@singh.im, pgsql-hackers@postgresql.org
Subject: Re: Unprivileged user can induce crash by using an SUSET param in
 PGOPTIONS
In-reply-to: <2361560.1658851473@sss.pgh.pa.us>
References: 
 <CABwTF4WXCbjEpVRq+G+MZeJEXU=2evYMb_DVdzXpWap5cczkcQ@mail.gmail.com>
 <Ytn2ssEKdzPFM3Vf@paquier.xyz>
 <20220722.151600.1094104349120879204.horikyota.ntt@gmail.com>
 <729330.1658516182@sss.pgh.pa.us> <20220722223359.GB3998906@nathanxps13>
 <763512.1658529844@sss.pgh.pa.us> <20220722225615.GC3998906@nathanxps13>
 <954936.1658597004@sss.pgh.pa.us> <20220725034040.GA4085281@nathanxps13>
 <1834276.1658720963@sss.pgh.pa.us> <20220725043044.GC4085281@nathanxps13>
 <2015981.1658759562@sss.pgh.pa.us> <87ilnli57b.fsf@wibble.ilmari.org>
 <2062116.1658778378@sss.pgh.pa.us> <87edy7j1zz.fsf@wibble.ilmari.org>
 <2361560.1658851473@sss.pgh.pa.us>
Comments: In-reply-to Tom Lane <tgl@sss.pgh.pa.us>
	message dated "Tue, 26 Jul 2022 12:04:33 -0400"
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Date: Wed, 27 Jul 2022 19:01:00 -0400
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I wrote:
> =?utf-8?Q?Dagfinn_Ilmari_Manns=C3=A5ker?= <ilmari@ilmari.org> writes:
>> Thanks!  Just one minor nitpick: setting an %ENV entry to `undef`
>> doesn't unset the environment variable, it sets it to the empty string.
>> To unset a variable it needs to be deleted from %ENV, i.e. `delete
>> $ENV{PGUSER};`.

> Ah.  Still, libpq doesn't distinguish, so the test works anyway.
> Not sure if it's worth changing.

Meh ... I had to un-break the test for Windows, so did this while
at it, using the local-in-block method.  Thanks for the suggestion.

			regards, tom lane