Re: forkbombing Linux distributions

Felipe Alfaro Solana
2005-03-30T23:47:19Z

On Mon, 28 Mar 2005 19:28:20 +0200, Matthieu Castet
<mat@ensilinx1.imag.fr> wrote:
> > The memory limits aren't good enough either: if you set them low
> > enough that memory-forkbombs are unperilous for
> > RLIMIT_NPROC*RLIMIT_DATA, it's probably too low for serious
> > applications.
>
> yes, if you want to run application like openoffice.org you need at
> least 200Mo. If you want that your system is usable, you need at least 40 process per user. So 40*200 = 8Go, and it don't think you have all this memory...
>
> I think per user limit could be a solution.
>
> attached a small fork-memory bombing.

Doesn't do anything on my machine:

# ulimits -a
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

it tops at 100 processes and eats a little CPU... although the system
is under load, it's completely responsive.