From owner-freebsd-security Tue Sep 15 07:42:25 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id HAA20275 for freebsd-security-outgoing; Tue, 15 Sep 1998 07:42:25 -0700 (PDT) (envelope-from owner-freebsd-security@FreeBSD.ORG) Received: from ns0.fast.net.uk (ns0.fast.net.uk [194.207.104.1]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id HAA20264 for ; Tue, 15 Sep 1998 07:42:22 -0700 (PDT) (envelope-from netadmin@fastnet.co.uk) Received: from bofh.fast.net.uk (bofh.fast.net.uk [194.207.104.22]) by ns0.fast.net.uk (8.9.0/8.8.7) with ESMTP id PAA00879; Tue, 15 Sep 1998 15:41:58 +0100 (BST) Received: from bofh.fast.net.uk (bofh.fast.net.uk [194.207.104.22]) by bofh.fast.net.uk (8.9.1/8.8.8) with SMTP id PAA00996; Tue, 15 Sep 1998 15:41:57 +0100 (BST) (envelope-from netadmin@fastnet.co.uk) Date: Tue, 15 Sep 1998 15:41:57 +0100 (BST) From: Jay Tribick X-Sender: netadmin@bofh.fast.net.uk To: "Jason J. Horton" cc: security@FreeBSD.ORG Subject: Re: grep ohdear /dev/zero in a tight loop freezes FreeBSD && OpenBSD In-Reply-To: <35FE7C66.5E73C4B6@intercom.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org | > Problem | > ------- | > Executing the following shell script effectively freezes a | > BSD box (tested on FreeBSD 2.2.6 & latest OpenBSD) regardless of the above | > process, cpu and memory restrictions within 15-30 seconds: | > | > #!/bin/bash | > while() do | > grep ohdear /dev/zero & | > done | > | > Any ideas on how to fix this or secure against it? | Don't allow users on your system. I don't, it's just something I noticed while I was trying to break my system :) Hehe.. The resource limits are fine for protecting against things like fork() rabbits etc. but for some reason the above overrides them. Regards, Jay Tribick -- [| Network Admin | FastNet International | http://fast.net.uk/ |] [| Finger netadmin@fastnet.co.uk for contact info & PGP PubKey |] [| +44 (0)1273 T: 677633 F: 621631 e: netadmin@fast.net.uk |] To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message