From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 88BA7C433E1 for ; Tue, 19 May 2020 00:01:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 69F452072C for ; Tue, 19 May 2020 00:01:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726442AbgESABE (ORCPT ); Mon, 18 May 2020 20:01:04 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:53872 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726053AbgESABE (ORCPT ); Mon, 18 May 2020 20:01:04 -0400 Received: from in02.mta.xmission.com ([166.70.13.52]) by out02.mta.xmission.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1japgp-0000OE-IQ; Mon, 18 May 2020 18:00:59 -0600 Received: from ip68-227-160-95.om.om.cox.net ([68.227.160.95] helo=x220.xmission.com) by in02.mta.xmission.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.87) (envelope-from ) id 1japgk-0000i6-TC; Mon, 18 May 2020 18:00:59 -0600 From: ebiederm@xmission.com (Eric W. Biederman) To: Christian Brauner Cc: Jann Horn , Kees Cook , Al Viro , Andrew Morton , Tetsuo Handa , Eric Biggers , Dmitry Vyukov , linux-fsdevel , linux-security-module , Linux API , kernel list References: <20200518055457.12302-1-keescook@chromium.org> <20200518055457.12302-2-keescook@chromium.org> <20200518130251.zih2s32q2rxhxg6f@wittgenstein> <20200518144627.sv5nesysvtgxwkp7@wittgenstein> Date: Mon, 18 May 2020 18:57:15 -0500 In-Reply-To: <20200518144627.sv5nesysvtgxwkp7@wittgenstein> (Christian Brauner's message of "Mon, 18 May 2020 16:46:27 +0200") Message-ID: <87blmk3ig4.fsf@x220.int.ebiederm.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1japgk-0000i6-TC;;;mid=<87blmk3ig4.fsf@x220.int.ebiederm.org>;;;hst=in02.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX19DeuOkpDOKLgt2uTPMIXubiPZdr97oZ0k= X-SA-Exim-Connect-IP: 68.227.160.95 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: Re: [PATCH 1/4] exec: Change uselib(2) IS_SREG() failure to EACCES X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Christian Brauner writes: > On Mon, May 18, 2020 at 04:43:20PM +0200, Jann Horn wrote: >> On Mon, May 18, 2020 at 3:03 PM Christian Brauner >> wrote: >> > Also - gulp (puts on flame proof suit) - may I suggest we check if there >> > are any distros out there that still set CONFIG_USELIB=y >> >> Debian seems to have it enabled on x86... >> >> https://salsa.debian.org/kernel-team/linux/-/blob/master/debian/config/kernelarch-x86/config#L1896 >> >> A random Ubuntu 19.10 VM I have here has it enabled, too. > > I wonder if there's any program - apart from _ancient_ glibc out there > that actually use it... > I looked at uselib in codsearch but the results were quite unspecific > but I didn't look too close. So the thing to do is to have a polite word with people who build Ubuntu and Debian kernels and get them to disable the kernel .config. A quick look suggets it is already disabled in RHEL8. It cannot be disabled in RHEL7. Then in a few years we can come back and discuss removing the uselib system call, base on no distributions having it enabled. If it was only libc4 and libc5 that used the uselib system call then it can probably be removed after enough time. We can probably reorganize the code before the point it is clearly safe to drop support for USELIB to keep it off to the side so USELIB does not have any ongoing mainteance costs. For this patchset I think we need to assume uselib will need to be maintained for a bit longer. Eric