[pups] User Mode DoS Attacks (was Re: Issues of AUUGN)

Bill Gunshannon bill at cs.uofs.edu
Fri Oct 6 00:33:19 AEST 2006

>> But you'd need kernel mode for that; this is a DoS attack (one of the
>> first?) launched by a user.
> The userland DoS I remember:
> main() {
> 	while(1)
> 		fork();
> }

Typical "Rabbit Program".

> And in fact I tried it once on the 11/45 I had access to. Not pretty.
> It can be made less disastrous by judicious addition of a wait(); call.
> --Milo, wondering how contemporary UNIX will deal with such
> pathological behavior....

Not necessarily pathological.  I have students do it all the time
in the early parts of the Operating Systems Course.  The only one
it denies service to on contemorary UNIX is the individual who does
it.  Process limits are by user, not by system.


Bill Gunshannon          |  de-moc-ra-cy (di mok' ra see) n.  Three wolves
bill at cs.scranton.edu     |  and a sheep voting on what's for dinner.
University of Scranton   |
Scranton, Pennsylvania   |         #include <std.disclaimer.h>

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