From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Date: Wed, 27 Feb 2013 10:05:47 -0800
From: Kees Cook <kees@outflux.net>
To: Josh Boyer <jwboyer@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	eparis@redhat.com, Christian Kujau <lists@nerdbynature.de>,
	stable@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] kmsg: Honor dmesg_restrict sysctl on /dev/kmsg
Message-ID: <20130227180547.GR26411@outflux.net>
References: <20130222181856.GA2419@hansolo.jdub.homelinux.org>
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Hi,

On Fri, Feb 22, 2013 at 01:18:57PM -0500, Josh Boyer wrote:
> Originally, the addition of dmesg_restrict covered both the syslog
> method of accessing dmesg, as well as /dev/kmsg itself.  This was done
> indirectly by security_syslog calling cap_syslog before doing any LSM
> checks.

Actually, are the security_syslog() checks in /dev/kmsg correct? There is
only one used in devkmsg_open which uses SYSLOG_ACTION_READ_ALL. Shouldn't
it be using SYSLOG_ACTION_OPEN? And have SYSLOG_ACTION_READ_ALL added to
devkmsg_read? (And should we add one for write?)

-Kees

-- 
Kees Cook
Chrome OS Security