Re: [patch 1/2] [RFC] Simple tamper-proof device filesystem.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi,

On Sun, December 16, 2007 13:03, Tetsuo Handa wrote:
> Hello.
>
> David Newall wrote:
>> > You won't be able to login to the system because /sbin/mingetty
>> > fails to "chown/chmod" /dev/tty* if /dev is mounted for read-only mode.
>>
>> Good point.  So, if only root can modify files in /dev, what's the
>> problem you're fixing?  (I'm sure you tried to explain this in your
>> original post, but your reasons weren't clear to me.)
>
> In 2003, I was trying to make / partition read-only to avoid tampering system
> files.
> Use of policy based mandatory access control (such as SELinux) is
> one of ways to avoid tampering, but management of policy was a daunting task.
> So, I tried to store / partition in a read-only medium so that
> the system is free from tampering system files.
>
> When I attended at Security Stadium 2003 as a defense side,
> I was using devfs for /dev directory. The files in /dev directory
> were deleted by attckers and the administrator was unable to login.
> So I developed this filesystem so that attackers who got root privilege
> can't tamper files in /dev directory.

What prevents them from mounting tmpfs on top of /dev, bypassing your fs?

Also, if they have root there are plenty of ways to prevent an administrator
from logging in, e.g. using iptables or changing the password.

Greetings,

Indan


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux