Re: forkbombing Linux distributions

From: aq
Date: Wed Mar 23 2005 - 12:07:47 EST


On Wed, 23 Mar 2005 14:54:18 +0100, Natanael Copa <mlists@xxxxxxxxxx> wrote:
> On Wed, 2005-03-23 at 22:04 +0900, aq wrote:
> > On Wed, 23 Mar 2005 13:37:38 +0100, Natanael Copa <mlists@xxxxxxxxxx> wrote:
> > > > > This is an example of a program in C my friends gave me that forkbombs.
> > > > > My previous sysctl.conf hack can't stop this, but the /etc/limits solution
> > > > > enables the owner of the computer to do something about it as root.
> > > > >
> > > > > int main() { while(1) { fork(); } }
> > >
> > > I guess that "fork twice and exit" is worse than this?
> >
> > you meant code like this
> >
> > int main() { while(1) { fork(); fork(); exit(); } }
> >
> > is more harmful ? I dont see why (?)
>
> Because the parent disappears. When things like killall tries to kill
> the process its already gone but there are 2 new with new pids.
>

are you sure? the above forkbomb will stop quickly after just several
spawns because of exit().

I agree that make kernel more restrictive by default is a good approach.

thank you,
aq
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