From owner-freebsd-security Sun Jul 19 18:03:04 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id SAA20392 for freebsd-security-outgoing; Sun, 19 Jul 1998 18:03:04 -0700 (PDT) (envelope-from owner-freebsd-security@FreeBSD.ORG) Received: from whistle.com (s205m131.whistle.com [207.76.205.131]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id SAA20384 for ; Sun, 19 Jul 1998 18:02:59 -0700 (PDT) (envelope-from archie@whistle.com) Received: (from smap@localhost) by whistle.com (8.7.5/8.6.12) id SAA27768; Sun, 19 Jul 1998 18:02:05 -0700 (PDT) Received: from bubba.whistle.com(207.76.205.7) by whistle.com via smap (V1.3) id sma027766; Sun Jul 19 18:02:04 1998 Received: (from archie@localhost) by bubba.whistle.com (8.8.7/8.6.12) id SAA07953; Sun, 19 Jul 1998 18:02:04 -0700 (PDT) From: Archie Cobbs Message-Id: <199807200102.SAA07953@bubba.whistle.com> Subject: Re: The 99,999-bug question: Why can you execute from the stack? In-Reply-To: <199807192047.OAA02264@lariat.lariat.org> from Brett Glass at "Jul 19, 98 02:47:25 pm" To: brett@lariat.org (Brett Glass) Date: Sun, 19 Jul 1998 18:02:04 -0700 (PDT) Cc: security@FreeBSD.ORG X-Mailer: ELM [version 2.4ME+ PL38 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Brett Glass writes: > What I CAN'T understand is why FreeBSD allows the hack to occur. Why on > Earth would one want to allow code to be executed from the stack? The Intel As an almost-example of why executing on the stack is not completely crazy, consider JIT-compiling Java runtimes like kaffe. These dynamically compile Java methods into i386 executable instructions, then execute those methods. Kaffe actually does this on the heap I think, but it just as reasonable if it wanted to do it on the stack (eg, perhaps some kind of temporary method, trampoline code to get things going, etc). -Archie ___________________________________________________________________________ Archie Cobbs * Whistle Communications, Inc. * http://www.whistle.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe security" in the body of the message