19 Mar
2003
19 Mar
'03
10:29 a.m.
the problem i see with it is that, for this to be
useful, (ie, help
the people for which the capsys stuff is too much trouble), it has to
be in the kernel that comes with their distribution. but i really
don't see this getting into the mainline kernel...though perhaps media
friendly distros will put it in.
why do you see it this way?
if someone has already cracked security such that they can write to
(say) /proc/sys/kernel/rtuser, they already have the power to do more
or less anything to the machine. they can *already* run SCHED_FIFO
tasks, install trojans, shutdown the system, repartition and/or
overwrite the hard drive. adding the capacity to let non-root users
run SCHED_FIFO and call mlockall is already included in the set of
things they can do - the /proc file just makes it simpler.
in addition, if you add resource limits so that things can still be
killed, having user tasks running like this actually isn't much of a
problem - SCHED_FIFO and mlockall only represent a denial of service
attack if you can't kill them (as is the case at the moment).
--p