From owner-freebsd-hackers Wed Sep 9 19:34:53 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id TAA10084 for freebsd-hackers-outgoing; Wed, 9 Sep 1998 19:34:53 -0700 (PDT) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from rover.village.org (rover.village.org [204.144.255.49]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id TAA10066 for ; Wed, 9 Sep 1998 19:34:50 -0700 (PDT) (envelope-from imp@village.org) Received: from harmony [10.0.0.6] by rover.village.org with esmtp (Exim 1.71 #1) id 0zGwZ5-0005aX-00; Wed, 9 Sep 1998 20:34:31 -0600 Received: from harmony.village.org (localhost.village.org [127.0.0.1]) by harmony.village.org (8.9.1/8.8.3) with ESMTP id UAA08517 for ; Wed, 9 Sep 1998 20:35:30 -0600 (MDT) Message-Id: <199809100235.UAA08517@harmony.village.org> To: freebsd-hackers@FreeBSD.ORG Subject: syscalls and the stack Date: Wed, 09 Sep 1998 20:35:29 -0600 From: Warner Losh Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Question: do system calls need to be made from the executable stack? If this were disallowed, what would break? I know that a system like this wouldn't give total security, but it seems that at the cost of a few instructions per system call (which could be disabled, if you wanted), one could stop the smash the stack attacks cold. This would have the same vulnerabilities as the Solar Designer patches for Linux. However, a door that takes extra care to open is better than no door at all... Warner To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message