Feedback-ID: i0fe9450f:Fastmail
Date: Thu, 25 Jan 2024 13:37:22 +0900
From: Michael Paquier <michael@paquier.xyz>
To: Dmitry Koval <d.koval@postgrespro.ru>
Cc: pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #18274: Error 'invalid XML content'
Message-ID: <ZbHlgrPLtBZyr_QW@paquier.xyz>
References: <18274-98d16bc03520665f@postgresql.org>
 <1616257.1704651529@sss.pgh.pa.us>
 <5588db01-45be-48ff-b158-85f789bc502c@postgrespro.ru>
 <1314313.1705259848@sss.pgh.pa.us>
 <0eea123f-388a-41ea-9df3-d4606cf9ed8d@postgrespro.ru>
 <ZaRvbaQ8V9uGxXGD@paquier.xyz>
 <35ef78f9-8958-4225-ae7e-aead71b0feed@postgrespro.ru>
 <ZaZI4WAHZ67ZHq7p@paquier.xyz>
 <24e7412a-890c-46e3-b17d-addc39ff813f@postgrespro.ru>
 <ZacYXgM9A_CSLpD8@paquier.xyz>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha512;
	protocol="application/pgp-signature"; boundary="eba4yV05fvKkAauo"
Content-Disposition: inline
In-Reply-To: <ZacYXgM9A_CSLpD8@paquier.xyz>
Archived-At: 
 <https://www.postgresql.org/message-id/ZbHlgrPLtBZyr_QW%40paquier.xyz>
Precedence: bulk


--eba4yV05fvKkAauo
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Wed, Jan 17, 2024 at 08:59:26AM +0900, Michael Paquier wrote:
> This one had better be done first because it is required by your
> original issue, and that's what could make the buildfarm shaky.
>=20
> I have checked the other XML calls in the tree and did not spot
> anything else that ought to be changed, so I have extracted this stuff
> from your v2 and applied it on HEAD.  Let's see how it goes.

The security team has discussed 2197d06224a1 after a report from
coverity regarding the effects that issues like [1] would create in
the backend, and concluded that this patch should be reverted because
this could cause the backend to waste plently of CPU and/or memory
even if the application applied checks on the size of the data given
in input, and libxml2 does not offer guarantees that input limits are=20
respected under XML_PARSE_HUGE.

So I am planning to do do so in the next 24 hours.  Note that this
does not impact 65c5864d7fac, as XML_PARSE_NOENT is an immediate
substitute of xmlSubstituteEntitiesDefault().

[1]: https://en.wikipedia.org/wiki/Billion_laughs_attack
--
Michael

--eba4yV05fvKkAauo
Content-Type: application/pgp-signature; name="signature.asc"

-----BEGIN PGP SIGNATURE-----
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=nBws
-----END PGP SIGNATURE-----

--eba4yV05fvKkAauo--