Message-ID: <84006e443ef2dcfcbff8dcb3814c0c402b8ff7fd.camel@j-davis.com>
Subject: Re: Speed up ICU case conversion by using ucasemap_utf8To*()
From: Jeff Davis <pgsql@j-davis.com>
To: Andreas Karlsson <andreas@proxel.se>, Alexander Lakhin
 <exclusion@gmail.com>,  zengman <zengman@halodbtech.com>, pgsql-hackers
 <pgsql-hackers@postgresql.org>
Date: Mon, 13 Apr 2026 11:40:03 -0700
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On Wed, 2026-04-01 at 02:46 +0200, Andreas Karlsson wrote:
> On 3/12/26 5:00 AM, Alexander Lakhin wrote:
> > I've discovered that starting from c4ff35f10, the following query:
> > CREATE COLLATION c (provider =3D icu, locale =3D 'icu_something');
> >=20
> > makes asan detect (maybe dubious, but still..) stack-buffer-
> > overflow:
> > =3D=3D21963=3D=3DERROR: AddressSanitizer: stack-buffer-overflow on addr=
ess=20
>=20
> My proposed fix is that we allocate a ULOC_LANG_CAPACITY buffer for
> the=20
> language like we do in fix_icu_locale_str() instead of trying to be=20
> clever.

Thank you both!

Committed with minor revisions:

* also check the status code, just to be sure
* backport to 18 where the original code was introduced

Regards,
	Jeff Davis