Date: Fri, 4 Mar 2011 21:32:02 +0100
From: Pavel Machek <pavel@ucw.cz>
To: Vasiliy Kulikov <segoon@openwall.com>
Cc: linux-kernel@vger.kernel.org, security@kernel.org,
        Len Brown <len.brown@intel.com>, "Rafael J. Wysocki" <rjw@sisk.pl>,
        linux-pm@lists.linux-foundation.org
Subject: Re: [PATCH] power: disable hibernation if module loading is
 disabled
Message-ID: <20110304203201.GA22079@elf.ucw.cz>
References: <1299255084-4390-1-git-send-email-segoon@openwall.com>
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On Fri 2011-03-04 19:11:24, Vasiliy Kulikov wrote:
> If /proc/sys/kernel/modules_disabled is set to 1, then nobody (even full
> root) may not read/write arbitrary kernel memory.  In spite of it,
> hibernation allows anyone with an access to either /dev/snapshot or
> /sys/power/ make the full snapshot of the system.  This snapshot may be
> freely changed and uploaded back.

module loading has nothing to do with hibernation, and hibernation
already checks for CAP_ADMIN or something similary strong. I don't see
why this new check is needed.

In fact, you are probably breaking someone's setup right now.

> +	if (modules_disabled)
> +		return -EPERM;
> +
>  	error = platform_begin(platform_mode);

Hmm. How is this supposed to work with CONFIG_MODULES off?

NAK.
								Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
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