From owner-freebsd-stable@FreeBSD.ORG Wed Apr 4 17:34:31 2012 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 0FFCD1065670 for ; Wed, 4 Apr 2012 17:34:31 +0000 (UTC) (envelope-from freebsd-stable@m.gmane.org) Received: from plane.gmane.org (plane.gmane.org [80.91.229.3]) by mx1.freebsd.org (Postfix) with ESMTP id B18278FC08 for ; Wed, 4 Apr 2012 17:34:30 +0000 (UTC) Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1SFU6E-0002Me-TJ for freebsd-stable@freebsd.org; Wed, 04 Apr 2012 19:34:27 +0200 Received: from np-19-75.prenet.pl ([np-19-75.prenet.pl]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 04 Apr 2012 19:34:26 +0200 Received: from jb.1234abcd by np-19-75.prenet.pl with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 04 Apr 2012 19:34:26 +0200 X-Injected-Via-Gmane: http://gmane.org/ To: freebsd-stable@freebsd.org From: jb Date: Wed, 4 Apr 2012 17:34:12 +0000 (UTC) Lines: 21 Message-ID: References: <4F766F29.2030803@cs.stonybrook.edu> <4F79D88B.3040102@cs.stonybrook.edu> <4F79E27E.3000509@cs.stonybrook.edu> <4F79FCB8.1090003@cs.stonybrook.edu> <4F7A05C4.9070808@cs.stonybrook.edu> <20120403170259.GA94837@neutralgood.org> <1333550029.1090.67.camel@revolution.hippie.lan> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Complaints-To: usenet@dough.gmane.org X-Gmane-NNTP-Posting-Host: sea.gmane.org User-Agent: Loom/3.14 (http://gmane.org/) X-Loom-IP: 79.139.19.75 (Mozilla/5.0 (X11; FreeBSD i386; rv:10.0.2) Gecko/20100101 Firefox/10.0.2) Subject: Re: Text relocations in kernel modules X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 04 Apr 2012 17:34:31 -0000 Peter Wemm wemm.org> writes: > ... > There is no way to interfere because it is done outside of user space > entirely, **after** the file has been copied out of the file system. > You can do whatever you like to the file, but it has no effect because > all the relocation is done in a private kernel copy. > ... What if attack code (broadly understood) is part of module code, and is based on either or both of: - hidden (as to meaning and reloc targets) arrangement of relocations needed - has an ability of (self) activation during load/link and *relocations* process already under the privilege of the kernel ? Is that possible at all ? Would there be any protection against it (except giving up relocations as an enabling vehicle) ? jb