From owner-freebsd-bugs Fri Jun 29 10:20: 7 2001 Delivered-To: freebsd-bugs@hub.freebsd.org Received: from freefall.freebsd.org (freefall.freebsd.org [216.136.204.21]) by hub.freebsd.org (Postfix) with ESMTP id 7CFF137B406 for ; Fri, 29 Jun 2001 10:20:03 -0700 (PDT) (envelope-from gnats@FreeBSD.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.11.3/8.11.3) id f5THK3C06110; Fri, 29 Jun 2001 10:20:03 -0700 (PDT) (envelope-from gnats) Date: Fri, 29 Jun 2001 10:20:03 -0700 (PDT) Message-Id: <200106291720.f5THK3C06110@freefall.freebsd.org> To: freebsd-bugs@FreeBSD.org Cc: From: David Malone Subject: Re: misc/28522: The ability to crash any freebsd box with 8 lines of shell script Reply-To: David Malone Sender: owner-freebsd-bugs@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org The following reply was made to PR misc/28522; it has been noted by GNATS. From: David Malone To: Peter Pentchev 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 18:13:50 +0100 > 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...). If you allow you users to use resources of any sort then they can use them - you can't get around that. Some people have done things with fancy schedulers which split CPU time between uids as opposed to between processes - this might be of some help. (Mind you, you can do far worse in terms of making the system unresponisve than running 5 processes by just using 1 process and a few standard shell commands, and that's just what I can think of off the top of my head.) David. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message