Re: [PATCH] don't allow CAP_NET_ADMIN to load non-netdev kernelmodules

From: Vasiliy Kulikov
Date: Fri Feb 25 2011 - 12:48:05 EST


On Fri, Feb 25, 2011 at 12:25 -0500, Valdis.Kletnieks@xxxxxx wrote:
> And you stop an attacker from simply recompiling the module with a suitable
> MODULE_ALIAS line added, how, exactly? This patch may make sense down the
> road, but not while it's still trivial for a malicious root user to drop stuff
> into /lib/modules.

The threat is not a malicious root, but non-root with CAP_NET_ADMIN.
It's hardly possible to load arbitrary module into the kernel having
CAP_NET_ADMIN without other capabilities.

> And if you're going the route "but SELinux/SMACK/Tomoyo will prevent a malicious
> root user from doing that", then the obvious reply is "this should be part of those
> subsystems rather than something done one-off like this (especially as it has a chance
> of breaking legitimate setups that use the current scheme).

No, I don't want to add anything about LSMs at all.


Thanks,

--
Vasiliy Kulikov
http://www.openwall.com - bringing security into open computing environments
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