Re: [PATCH] [request for inclusion] Realtime LSM

Jack O'Quin
2005-01-12T01:42:47Z

Chris Wright <chrisw@osdl.org> writes:

> * Paul Davis (paul@linuxaudiosystems.com) wrote:
>> >On Tue, Jan 11, 2005 at 04:38:14PM -0500, Lee Revell wrote:
>> >> Yes but a bug in an app running as root can trash the filesystem. The
>> >> worst you can do with RT privileges is lock up the machine.
>> >
>> >several filesystem and IO threads run at prio -10 but not RT.
>> >That makes me a bit less sure of your statement....
>>
>> Its completely orthogonal. Lee didn't say "tasks running without RT
>> can't mess up filesystems". He said "tasks running as root can trash
>> the filesystem" and "tasks running as RT can lock up the
>> machine". obviously, the intersection point (a root, RT task) is
>> double trouble.
>
> This is straying from the core issue... But, Arjan's saying that an RT
> (non-root) task could trash the filesystem if it deadlocks the machine
> (because those important fs and IO threads don't run).

Lexicographic ambiguity: Lee and Paul are using "trash" for things
like installing a hidden suid root shell or co-opting sendmail into an
open spam relay. Arjan just means crashing the system which forces
reboot to run fsck.
--
joq