From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mp1 ([2001:41d0:2:4a6f::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by ms11 with LMTPS id CHu0Dh1GJGCQUQAA0tVLHw (envelope-from ) for ; Wed, 10 Feb 2021 20:46:21 +0000 Received: from aspmx1.migadu.com ([2001:41d0:2:4a6f::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by mp1 with LMTPS id EMBmCh1GJGAzAgAAbx9fmQ (envelope-from ) for ; Wed, 10 Feb 2021 20:46:21 +0000 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by aspmx1.migadu.com (Postfix) with ESMTPS id 8B99B940481 for ; Wed, 10 Feb 2021 20:46:20 +0000 (UTC) Received: from localhost ([::1]:52266 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l9wNO-0007ly-UT for larch@yhetil.org; Wed, 10 Feb 2021 15:46:19 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:39216) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l9wN8-0007lF-Pu for guix-devel@gnu.org; Wed, 10 Feb 2021 15:46:02 -0500 Received: from fencepost.gnu.org ([2001:470:142:3::e]:55804) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l9wN7-0002UQ-HZ; Wed, 10 Feb 2021 15:46:01 -0500 Received: from [2a01:e0a:1d:7270:af76:b9b:ca24:c465] (port=45612 helo=ribbon) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1l9wN5-0002ur-ND; Wed, 10 Feb 2021 15:46:01 -0500 From: =?utf-8?Q?Ludovic_Court=C3=A8s?= To: Maxime Devos Subject: Re: Potential security weakness in Guix services References: <87k0rrls0z.fsf@gnu.org> <08F0CD76-DDCF-4CFA-AE8D-5FB165A62B25@lepiller.eu> <87o8h2ehy7.fsf@gnu.org> <69968b3a01d872cabdf55a94b6c82d5057e010c9.camel@telenet.be> <87v9b66dm1.fsf@gnu.org> <56adb5efa894304c27beba99b07e2f8cfd8ee7cb.camel@telenet.be> <87sg68zy15.fsf@gnu.org> <3c869a8c38ba8c98e29a06de1404f9dbf8fe7a68.camel@telenet.be> X-URL: http://www.fdn.fr/~lcourtes/ X-Revolutionary-Date: 22 =?utf-8?Q?Pluvi=C3=B4se?= an 229 de la =?utf-8?Q?R=C3=A9volution?= X-PGP-Key-ID: 0x090B11993D9AEBB5 X-PGP-Key: http://www.fdn.fr/~lcourtes/ludovic.asc X-PGP-Fingerprint: 3CE4 6455 8A84 FDC6 9DB4 0CFB 090B 1199 3D9A EBB5 X-OS: x86_64-pc-linux-gnu Date: Wed, 10 Feb 2021 21:45:58 +0100 In-Reply-To: <3c869a8c38ba8c98e29a06de1404f9dbf8fe7a68.camel@telenet.be> (Maxime Devos's message of "Sat, 06 Feb 2021 23:01:49 +0100") Message-ID: <87ft23648p.fsf@gnu.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-BeenThere: guix-devel@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Development of GNU Guix and the GNU System distribution." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: guix-devel@gnu.org Errors-To: guix-devel-bounces+larch=yhetil.org@gnu.org Sender: "Guix-devel" X-Migadu-Flow: FLOW_IN X-Migadu-Spam-Score: -2.86 Authentication-Results: aspmx1.migadu.com; dkim=none; dmarc=pass (policy=none) header.from=gnu.org; spf=pass (aspmx1.migadu.com: domain of guix-devel-bounces@gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=guix-devel-bounces@gnu.org X-Migadu-Queue-Id: 8B99B940481 X-Spam-Score: -2.86 X-Migadu-Scanner: scn0.migadu.com X-TUID: r4YwBZNxo7Oh Hi Maxime, Maxime Devos skribis: > On Sat, 2021-02-06 at 22:28 +0100, Ludovic Court=C3=A8s wrote: >> Maxime Devos skribis: >>=20 >> I just remembered this subtlety: during bootup, the activation code is >> evaluated by the Guile that=E2=80=99s in the initrd, which is a >> statically-linked Guile, and thus we can=E2=80=99t use =E2=80=98dynamic-= link=E2=80=99 & co. in >> there. :-/ > > I remember trying to use make-forkexec-constructor/container from activat= ion > code, which didn't work, due to some uses of dynamic-func ... I see two > possible options to take: > > * extend gnu/packages/patches/guile-linux-syscalls.patch with, say, > a "%extra-function-pointers" procedure returning a vector (or alist, > or something else) of pointers to the relevant C functions. This > allows us to write the FFI code mostly in Scheme, and only write C > code for obtaining function pointer. > > * extend gnu/packages/patches/guile-linux-syscalls.patch with > additional bindings, or write a patch extending guile itself with > fchownat > and other *at support. This (second) patch should be > submitted upstream, but can be kept in gnu/packages/patches until > support for *at > functionality makes it upstream. Like I wrote earlier in <87zh0gzy52.fsf@gnu.org>, I think we can fix this particular issue (=E2=80=98mkdir-p/perms=E2=80=99) without resorting t= o the *at functions, and I think that=E2=80=99s what we should do. Support for *at will be useful, especially if we can make it part of Guile proper, but it=E2=80=99s not an absolute prerequisite for the issue at hand. WDYT? Thanks for looking into this! Ludo=E2=80=99.