Date: Fri, 29 Feb 2008 17:40:07 -0300
From: "Luiz Fernando N. Capitulino" <lcapitulino@mandriva.com.br>
To: serge@hallyn.com
Cc: lkml <linux-kernel@vger.kernel.org>, linux-security-module@vger.kernel.org,
       Andrew Morgan <morgan@kernel.org>, Stephen Smalley <sds@epoch.ncsc.mil>,
       Mike Galbraith <efault@gmx.de>, buraphalinuxserver@gmail.com,
       elendil@planet.nl
Subject: Re: [PATCH 1/1] file capabilities: remove cap_task_kill()
Message-ID: <20080229174007.0a934cc6@mandriva.com.br>
In-Reply-To: <20080228173817.GA32661@vino.hallyn.com>
References: <20080228173817.GA32661@vino.hallyn.com>
Organization: Mandriva
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Em Thu, 28 Feb 2008 11:38:17 -0600
serge@hallyn.com escreveu:

| The original justification for cap_task_kill() was as follows:
| 
| 	check_kill_permission() does appropriate uid equivalence checks.
| 	However with file capabilities it becomes possible for an
| 	unprivileged user to execute a file with file capabilities
| 	resulting in a more privileged task with the same uid.
| 
| However now that cap_task_kill() always returns 0 (permission
| granted) when p->uid==current->uid, the whole hook is worthless,
| and only likely to create more subtle problems in the corner cases
| where it might still be called but return -EPERM.  Those cases
| are basically when uids are different but euid/suid is equivalent
| as per the check in check_kill_permission().
| 
| This patch removes cap_task_kill().

 2.6.24 seems to have the same bug, what about a rediff for it and
submit the patch to -stable team?

 Thanks.

-- 
Luiz Fernando N. Capitulino
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