Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751164AbWIYU7H (ORCPT ); Mon, 25 Sep 2006 16:59:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751178AbWIYU7G (ORCPT ); Mon, 25 Sep 2006 16:59:06 -0400 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:12256 "EHLO amd.ucw.cz") by vger.kernel.org with ESMTP id S1751191AbWIYU7F (ORCPT ); Mon, 25 Sep 2006 16:59:05 -0400 Date: Mon, 25 Sep 2006 12:53:55 +0200 From: Pavel Machek To: David Wagner Cc: linux-kernel@vger.kernel.org Subject: Re: [patch] remove MNT_NOEXEC check for PROT_EXEC mmaps Message-ID: <20060925105355.GA4390@elf.ucw.cz> References: <45150CD7.4010708@aknet.ru> <4516B2C8.4050202@aknet.ru> <4516B721.5070801@redhat.com> <4516C9D0.3080606@aknet.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.11+cvs20060126 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 996 Lines: 25 Hi! > >> The consensus has been to add the same checks to mprotect. They were > >> not left out intentionally. > > > >But how about the anonymous mmap with PROT_EXEC set? > > I'm curious about this, too. ld-linux.so is a purely unprivileged > program. It isn't setuid root. Can you write a variant of ld-linux.so > that reads an executable into memory off of a partition mounted noexec and > then begins executing that code? (perhaps by using anonymous mmap > with Yes, you can, but to execute your ld-linux-ignore-noexec.so variant, you need to put it somewhere with exec permissions, right? Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/