Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1946429AbWJSUYJ (ORCPT ); Thu, 19 Oct 2006 16:24:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1946442AbWJSUYJ (ORCPT ); Thu, 19 Oct 2006 16:24:09 -0400 Received: from mx1.redhat.com ([66.187.233.31]:54686 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S1946429AbWJSUYH (ORCPT ); Thu, 19 Oct 2006 16:24:07 -0400 Date: Thu, 19 Oct 2006 16:23:54 -0400 From: Dave Jones To: Marcus Meissner Cc: linux-kernel@vger.kernel.org, akpm@osdl.org Subject: Re: [PATCH] binfmt_elf: randomize PIE binaries Message-ID: <20061019202354.GI26530@redhat.com> Mail-Followup-To: Dave Jones , Marcus Meissner , linux-kernel@vger.kernel.org, akpm@osdl.org References: <20061019143547.GA8586@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20061019143547.GA8586@suse.de> User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1381 Lines: 37 On Thu, Oct 19, 2006 at 04:35:47PM +0200, Marcus Meissner wrote: > --- linux-2.6.18/fs/binfmt_elf.c.xx 2006-10-19 11:21:49.000000000 +0200 > +++ linux-2.6.18/fs/binfmt_elf.c 2006-10-19 11:24:58.000000000 +0200 > @@ -856,7 +856,12 @@ static int load_elf_binary(struct linux_ > * default mmap base, as well as whatever program they > * might try to exec. This is because the brk will > * follow the loader, and is not movable. */ > - load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr); > + if (current->flags & PF_RANDOMIZE) > + load_bias = randomize_range(0, ELF_ET_DYN_BASE, > + vaddr); > + else > + load_bias = ELF_ET_DYN_BASE - vaddr; > + load_bias = ELF_PAGESTART(load_bias); > } > > error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt, vaddr seems odd to be using as the len for randomize_range doesn't it ? Should that be randomize_range(0, ELF_ET_DYN_BASE, ELF_ET_DYN_BASE - vaddr); maybe ? Also, when we get to the elf_map(), we add vaddr back again, but in the randomize_range case, we never subtracted it. hmm? Dave -- http://www.codemonkey.org.uk - 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/