From owner-freebsd-hackers Wed Jul 15 16:08:11 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id QAA02175 for freebsd-hackers-outgoing; Wed, 15 Jul 1998 16:08:11 -0700 (PDT) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from mail.camalott.com (root@mail.camalott.com [208.203.140.2]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id QAA02162 for ; Wed, 15 Jul 1998 16:08:06 -0700 (PDT) (envelope-from joelh@gnu.org) Received: from detlev.UUCP (tex-112.camalott.com [208.229.74.112]) by mail.camalott.com (8.8.7/8.8.5) with ESMTP id SAA05526; Wed, 15 Jul 1998 18:08:35 -0500 Received: (from joelh@localhost) by detlev.UUCP (8.8.8/8.8.8) id SAA15384; Wed, 15 Jul 1998 18:07:48 -0500 (CDT) (envelope-from joelh) Date: Wed, 15 Jul 1998 18:07:48 -0500 (CDT) Message-Id: <199807152307.SAA15384@detlev.UUCP> To: luoqi@watermarkgroup.com CC: matthew@wolfepub.com, hackers@FreeBSD.ORG In-reply-to: <199807152155.RAA07159@lor.watermarkgroup.com> (message from Luoqi Chen on Wed, 15 Jul 1998 17:55:54 -0400 (EDT)) Subject: Re: Protecting data in memory From: Joel Ray Holveck Reply-to: joelh@gnu.org References: <199807152155.RAA07159@lor.watermarkgroup.com> Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG >>> Is there any way to protect a programs memory space from all users, even >>> root? >> No. root always has access to all memory space. Consider: If it were >> otherwise, root could just patch the kernel and gain whatever access >> was needed. > Actually, if you raise the securelevel to 1 or above, not even root can > access kernel memory space (see init(8)). Er, according to init(8), then root cannot *write* to kernel memory. I am basically familiar with securelevel. I oversimplified my example. Best, joelh -- Joel Ray Holveck - joelh@gnu.org - http://www.wp.com/piquan Fourth law of programming: Anything that can go wrong wi sendmail: segmentation violation - core dumped To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message