Fork bombing a Linux machine as a non-root user

[Markku Kolkka]

Johnathan Bailes kirjoitti viestissään (lähetysaika lauantai, 19. 
maaliskuuta 2005 17:12):
> On Sat, 19 Mar 2005 08:07:42 -0500, Jim Buchanan 
<jbuchana at gmail.com> wrote:
> > I just tried a fork bomb on a reaonably updated fc3 box.
> > Locked it up tight, I had to use the power switch.
> >
> > The default ulimit for user processes was set at 4095.
> >
>
> ulimit -a
> core file size          (blocks, -c) 0
> data seg size           (kbytes, -d) unlimited
> file size               (blocks, -f) unlimited
> pending signals                 (-i) 1024
> max locked memory       (kbytes, -l) 32
> max memory size         (kbytes, -m) unlimited
> open files                      (-n) 1024
> pipe size            (512 bytes, -p) 8
> POSIX message queues     (bytes, -q) 819200
> stack size              (kbytes, -s) 10240
> cpu time               (seconds, -t) unlimited
> max user processes              (-u) 2045
> virtual memory          (kbytes, -v) unlimited
> file locks                      (-x) unlimited
>
> Weird my fairly stock Fedora Core 3 has a ulimit of 2045?

My machine has the limit set at 8191. Looks like it's determined 
dynamically, maybe from RAM size? I have 512MB.

> Is that enough to grind a box to its knees?

Fork bomb jammed my machine with the default limit, with ulimit 
-u 1024 there were no problems.

-- 
 Markku Kolkka
 markku.kolkka at iki.fi