Fork bombing a Linux machine as a non-root user

[Felipe Alfaro Solana]

On 19 Mar 2005, at 16:12, Johnathan Bailes 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?

These are mine after running bastille:

core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
file size               (blocks, -f) unlimited
pending signals                 (-i) 4095
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) 8192
cpu time               (seconds, -t) unlimited
max user processes              (-u) 100
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

This is a workstation, so a limit of 100 processes per user are quite 
reasonable.