From owner-freebsd-security Sun Jul 19 15:04:05 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id PAA29703 for freebsd-security-outgoing; Sun, 19 Jul 1998 15:04:05 -0700 (PDT) (envelope-from owner-freebsd-security@FreeBSD.ORG) Received: from frmug.org (frmug-gw.frmug.org [193.56.58.252]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id PAA29684 for ; Sun, 19 Jul 1998 15:04:01 -0700 (PDT) (envelope-from roberto@keltia.freenix.fr) Received: (from uucp@localhost) by frmug.org (8.9.1/frmug-2.3/nospam) with UUCP id AAA10777 for security@FreeBSD.ORG; Mon, 20 Jul 1998 00:03:42 +0200 (CEST) (envelope-from roberto@keltia.freenix.fr) Received: (from roberto@localhost) by keltia.freenix.fr (8.9.0.Beta4/keltia-2.14/nospam) id XAA09116 for security@FreeBSD.ORG; Sun, 19 Jul 1998 23:55:32 +0200 (CEST) (envelope-from roberto) Message-ID: <19980719235532.A8630@keltia.freenix.fr> Date: Sun, 19 Jul 1998 23:55:32 +0200 From: Ollivier Robert To: security@FreeBSD.ORG Subject: Re: The 99,999-bug question: Why can you execute from the stack? Mail-Followup-To: security@FreeBSD.ORG References: <199807192047.OAA02264@lariat.lariat.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.93i In-Reply-To: <199807192047.OAA02264@lariat.lariat.org>; from Brett Glass on Sun, Jul 19, 1998 at 02:47:25PM -0600 X-Operating-System: FreeBSD 3.0-CURRENT ctm#4462 AMD-K6 MMX @ 225 MHz Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org According to Brett Glass: > segmentation model normally prevents this, and there's additional hardware > in the MMU that's supposed to be able to preclude it. Why does the OS leave > this gigantic hole open? Why not just close it? As it has been said several times already, gcc itself make code on the stack a bit difficult to forbid. It generates code on the stack for "trampolines". -- Ollivier ROBERT -=- FreeBSD: The Power to Serve! -=- roberto@keltia.freenix.fr FreeBSD keltia.freenix.fr 3.0-CURRENT #61: Sun Jul 12 14:38:23 CEST 1998 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe security" in the body of the message