Date: Fri, 29 Jun 2001 10:10:05 -0700 (PDT) From: Peter Pentchev <roam@orbitel.bg> To: freebsd-bugs@FreeBSD.org Subject: Re: misc/28522: The ability to crash any freebsd box with 8 lines of shell script Message-ID: <200106291710.f5THA5V02424@freefall.freebsd.org>
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The following reply was made to PR misc/28522; it has been noted by GNATS. From: Peter Pentchev <roam@orbitel.bg> To: David Malone <dwmalone@maths.tcd.ie> Cc: freebsd-gnats-submit@FreeBSD.org Subject: Re: misc/28522: The ability to crash any freebsd box with 8 lines of shell script Date: Fri, 29 Jun 2001 20:08:29 +0300 On Fri, Jun 29, 2001 at 10:00:19AM -0700, David Malone wrote: > The following reply was made to PR misc/28522; it has been noted by GNATS. > > From: David Malone <dwmalone@maths.tcd.ie> > To: Ryan Malek <squirl@exotica.mach3ww.com> > Cc: freebsd-gnats-submit@FreeBSD.org > Subject: Re: misc/28522: The ability to crash any freebsd box with 8 lines of shell script > Date: Fri, 29 Jun 2001 17:54:34 +0100 > > On Fri, Jun 29, 2001 at 09:11:32AM -0700, Ryan Malek wrote: > > I wrote a small paper documenting this problem. I _think_ its quite a serious problem considering the fact that I can drop any FreeBSD box with 7 or 8 lines of shell scripting. Here is the paper I wrote on it: > > > > http://exotica.mach3ww.com/~squirl/devzero-vuln.txt > > You seem to have rediscovered the fork bomb - if the admin has > suitable process limits set then this shouldn't be a problem. Try > saying "limit maxproc 10" and running the catbomb, you should find > it is less effective. > > (I'll close the PR unless there is more to the problem than this). But is it really ineffective? Just five instances of 'cat' would consume quite a lot of kernel resources (fake read, fake write, two syscalls, data copies to userspace and back...). G'luck, Peter -- I am the thought you are now thinking. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message
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