Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755542AbYJCF0m (ORCPT ); Fri, 3 Oct 2008 01:26:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752818AbYJCF0e (ORCPT ); Fri, 3 Oct 2008 01:26:34 -0400 Received: from mylar.outflux.net ([69.93.193.226]:46624 "EHLO mylar.outflux.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751865AbYJCF0e (ORCPT ); Fri, 3 Oct 2008 01:26:34 -0400 Date: Thu, 2 Oct 2008 22:25:39 -0700 From: Kees Cook To: Jakub Jelinek Cc: Roland McGrath , linux-kernel@vger.kernel.org, Ulrich Drepper , libc-alpha@sourceware.org Subject: Re: [PATCH] ELF: implement AT_RANDOM for future glibc use Message-ID: <20081003052539.GR10632@outflux.net> References: <20081001201116.GD12527@outflux.net> <48E3EFD6.2010704@redhat.com> <20081001215657.GH12527@outflux.net> <20081001220948.GC32107@sunsite.ms.mff.cuni.cz> <20081001222706.68E7E1544B4@magilla.localdomain> <20081003001616.GN10632@outflux.net> <20081003004340.GF32682@tyan-ft48-01.lab.bos.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081003004340.GF32682@tyan-ft48-01.lab.bos.redhat.com> Organization: Canonical X-HELO: www.outflux.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1129 Lines: 34 On Fri, Oct 03, 2008 at 02:43:40AM +0200, Jakub Jelinek wrote: > On Thu, Oct 02, 2008 at 05:16:16PM -0700, Kees Cook wrote: > > @@ -196,6 +198,18 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec, > > return -EFAULT; > > } > > > > + rand_size = CONFIG_SECURITY_AUXV_RANDOM_SIZE * sizeof(unsigned long); > > I believe you want sizeof (elf_addr_t) here instead. > > > + u_rand_bytes = NULL; > > + if (rand_size) { > > + unsigned char k_rand_bytes[CONFIG_SECURITY_AUXV_RANDOM_SIZE * > > + sizeof(unsigned long)]; > > And here too, because having a 64-bit kernel supply twice as much random > data to 32-bit programs as a 32-bit kernel would supply would be certainly > unexpected. Ah-ha! I see the 32-vs-64 elf_addr_t magic in fs/compat_binfmt_elf.c now. Excellent, I will send an updated patch. Thanks! -Kees -- Kees Cook Ubuntu Security Team -- 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/