From: Michael Paquier <michael@paquier.xyz>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Robin Haberkorn <haberkorn@b1-systems.de>
Cc: Jim Jones <jim.jones@uni-muenster.de>
Cc: pgsql-bugs@lists.postgresql.org
Cc: maralist86@mail.ru
Subject: Re: BUG #18943: Return value of a function 'xmlBufferCreate' is dereferenced at xpath.c:177 without checking for NUL
Date: Wed, 9 Jul 2025 09:45:07 +0900
Message-ID: <aG27k8a2y9fvak40@paquier.xyz> (raw)
In-Reply-To: <689495.1751981797@sss.pgh.pa.us>
References: <aEEingzOta_S_Nu7@paquier.xyz>
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<d2410ca0-c0dd-4f63-9e70-3d7a62a5d705@uni-muenster.de>
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<31f3480e-cd7d-4021-b392-87922572cc37@uni-muenster.de>
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<DB6KVQ60OJ8X.A8LWANY82NLG@b1-systems.de>
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<689495.1751981797@sss.pgh.pa.us>
On Tue, Jul 08, 2025 at 09:36:37AM -0400, Tom Lane wrote:
> The comment in xml_errorHandler() argues
Yep.
> So switching to _ALL (or even _WELL_FORMED) mode would result in
> nontrivial differences in the behavior of xpath.c's functions with
> bad input. Maybe that's a reasonable thing to do, but it's a
> question of user-visible behavior not just code cleanliness.
Yes, I don't see a huge advantage in doing the switch for this module.
If the gain in information in the error states grabbed from libxml2
makes it a win, that may be a different argument (I am fine to be
proved wrong), but I cannot get excited about that without more
data to claim it so.
I have quickly tested the change, and the xpath_string() path was one
area that immediately stood out, and we may report an incorrect error.
--
Michael
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To: pgsql-bugs@postgresql.org
Cc: michael@paquier.xyz, tgl@sss.pgh.pa.us, haberkorn@b1-systems.de, jim.jones@uni-muenster.de, pgsql-bugs@lists.postgresql.org, maralist86@mail.ru
Subject: Re: BUG #18943: Return value of a function 'xmlBufferCreate' is dereferenced at xpath.c:177 without checking for NUL
In-Reply-To: <aG27k8a2y9fvak40@paquier.xyz>
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