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Subject: Re: Is it possible to give the user the option to cancel forkbombs?
Date: Thu, 22 Nov 2007 00:05:32 +0000
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From: "(=?utf-8?q?=60=60-=5F-=C2=B4=C2=B4?=) -- Fernando" 
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On Saturday 17 November 2007 07:04:48 Martin Olsson wrote:
> Repro steps:
>=20
> 1. Install gutsy gibbon (or probably any ubuntu)
> 2. Start a gnome terminal
> 3. Run this command:
>=20
>     :(){ :|:& };:
>=20
> 4. Ubuntu starts to work furiously, after less than a second terminal=20
> gets flooded with "low resources" message, and within a few seconds the=20
> whole machine breaks down complete to the point where no a single pixel=20
> is updated and the mouse cannot be moved at all. It's not possible to=20
> escape to a ALT-Fn console terminal and CTRL-ALT-DEL does not work.
>=20
> Okay, so this is not as bad as winnuke.exe because it's not remote but I=
=20
> just did it on my shared hosting co and their server went down. And I=20
> mean seriously, there should be a way for a user to abort stuff that=20
> hogs resources this type of complete breakdown is NEVER acceptible. I=20
> had to power of the machine and my file system got royally screwed (long=
=20
> fsck etc).
>=20
> Some of you might say this is like the oldest trick in the book, yada=20
> yada yada...
>=20
> 		Martin

I used to see stuff like this happening on my University students test serv=
ers. Once they started doing forks inside for(;;), the server would go down.
Then they replaced the servers by vwmare machines, and now reboots are fast=
er.

But I would like to see installed by default some script like AND(Auto Nice=
 Daemon) or CpuLimit locking any and every process to a maximum of 90% afte=
r X seconds. That way one could allways launch a new command and kill it.
Of course, this is assuming that disk I/O is not our main prob, 'cause if t=
hat happens there's no way out.

=2D-=20
BUGabundo  :o)
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