Messages in this thread | | | Date | Mon, 17 Dec 2007 18:39:55 -0600 | From | "Serge E. Hallyn" <> | Subject | Re: [patch 1/2] [RFC] Simple tamper-proof device filesystem. |
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Quoting Tetsuo Handa (penguin-kernel@i-love.sakura.ne.jp): > Hello. > > Serge E. Hallyn wrote: > > CAP_MKNOD will be removed from its capability > I think it is not enough because the root can rename/unlink device files > (mv /dev/sda1 /dev/tmp; mv /dev/sda2 /dev/sda1; mv /dev/tmp /dev/sda2).
Sure but that doesn't bother us :)
The admin in the container has his own /dev directory and can do what he likes with the devices he's allowed to have. He just shouldn't have access to others. If he wants to rename /dev/sda1 to /dev/sda5 that's his choice.
> > To use your approach, i guess we would have to use selinux (or tomoyo) > > to enforce that devices may only be created under /dev? > Everyone can use this filesystem alone.
Sure but it is worthless alone.
No?
What will keep the container admin from doing 'mknod /root/hda1 b 3 1'?
> But use with MAC (or whatever access control mechanisms that prevent > attackers from unmounting/overlaying this filesystem) is recomennded.
-serge
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