Fork bombing a Linux machine as a non-root user

[Antonio Olivares]

--- Johnathan Bailes <johnathan.bailes at gmail.com>
wrote:
> On Sat, 19 Mar 2005 08:07:42 -0500, Jim Buchanan
> <jbuchana at gmail.com> wrote:
> > On Fri, 18 Mar 2005 13:08:31 -0500, M.Rudra
> <dr.rudra at gmail.com> wrote:
> > > So I googled "fork bombing" and after reading
> them, I have some doubts :
> > >
> > > 1] Is this applicable to newer version of FC3/4
> or will this affect
> > 
> > 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.
> > 
> > As many said, if you are worried, it is trivial to
> reduce this.
> > 
> 
> 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?
> 
> Is that enough to grind a box to its knees?
> 
> I put the ulimit to 1000 in the iptables script for
> my next kernel
> update reboot.
> 
> ulimit -u 1000
> 
> Is that is all that is needed?
> 
> -- 
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> 

I did the same and I get another number greater than
4095.  I am not concerned about this, but I would like
to share my data

[olivares at localhost ~]$ 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) 7677
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited
[olivares at localhost ~]$

Regards,

Antonio 


		
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