Subject: Re: [PATCH] sys_chroot() hook for additional chroot() jails
	enforcing
From: Lorenzo =?ISO-8859-1?Q?Hern=E1ndez_?=
	 =?ISO-8859-1?Q?Garc=EDa-Hierro?= <lorenzo@gnu.org>
To: "Serge E.Hallyn" <serue@us.ibm.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
       "linux-security-module@wirex.com" <linux-security-module@wirex.com>
In-Reply-To: <20050207225056.GA2388@IBM-BWN8ZTBWA01.austin.ibm.com>
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	 <20050207225056.GA2388@IBM-BWN8ZTBWA01.austin.ibm.com>
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Date: Tue, 08 Feb 2005 00:41:55 +0100
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El lun, 07-02-2005 a las 16:50 -0600, Serge E. Hallyn escribi=F3:
> Hi,
>=20
> If I understood you correct earlier, the only policy you needed to
> enforce was to prevent double-chrooting.  If that is the case, why is it
> not sufficient to keep a "process-has-used-chroot" flag in
> current->security which is set on the first call to
> capable(CAP_SYS_CHROOT) and inherited by forked children, after which
> calls to capable(CAP_SYS_CHROOT) are refused?
>=20
> Of course if you need to do more, then a hook might be necessary.

Yeah, checking that process is chrooted using the current macro and
denying if capable() gets it trying to access CAP_SYS_CHROOT it's the
way that vSecurity currently does it.

But the hook will have to handle some chdir enforcing that can't be done
with current hooks, I will explain it further tomorrow.

It's too late here ;)

Cheers,
--=20
Lorenzo Hern=E1ndez Garc=EDa-Hierro <lorenzo@gnu.org>=20
[1024D/6F2B2DEC] & [2048g/9AE91A22][http://tuxedo-es.org]

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