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=-0.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 E4E99C83001 for ; Thu, 30 Apr 2020 08:07:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C9FA42073E for ; Thu, 30 Apr 2020 08:07:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727789AbgD3IH4 (ORCPT ); Thu, 30 Apr 2020 04:07:56 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:37501 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726453AbgD3IHz (ORCPT ); Thu, 30 Apr 2020 04:07:55 -0400 Received: from ip5f5af183.dynamic.kabel-deutschland.de ([95.90.241.131] helo=wittgenstein) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1jU4EW-0000NO-1I; Thu, 30 Apr 2020 08:07:48 +0000 Date: Thu, 30 Apr 2020 10:07:46 +0200 From: Christian Brauner To: Aleksa Sarai Cc: =?utf-8?Q?Micka=C3=ABl_Sala=C3=BCn?= , linux-kernel@vger.kernel.org, Alexei Starovoitov , Al Viro , Andy Lutomirski , Christian Heimes , Daniel Borkmann , Deven Bowers , Eric Chiang , Florian Weimer , James Morris , Jan Kara , Jann Horn , Jonathan Corbet , Kees Cook , Matthew Garrett , Matthew Wilcox , Michael Kerrisk , =?utf-8?Q?Micka=C3=ABl_Sala=C3=BCn?= , Mimi Zohar , Philippe =?utf-8?Q?Tr=C3=A9buchet?= , Scott Shell , Sean Christopherson , Shuah Khan , Steve Dower , Steve Grubb , Thibaut Sautereau , Vincent Strubel , kernel-hardening@lists.openwall.com, linux-api@vger.kernel.org, linux-security-module@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH v3 0/5] Add support for RESOLVE_MAYEXEC Message-ID: <20200430080746.n26fja2444w6i2db@wittgenstein> References: <20200428175129.634352-1-mic@digikod.net> <20200430015429.wuob7m5ofdewubui@yavin.dot.cyphar.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20200430015429.wuob7m5ofdewubui@yavin.dot.cyphar.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 30, 2020 at 11:54:29AM +1000, Aleksa Sarai wrote: > On 2020-04-28, Mickaël Salaün wrote: > > The goal of this patch series is to enable to control script execution > > with interpreters help. A new RESOLVE_MAYEXEC flag, usable through > > openat2(2), is added to enable userspace script interpreter to delegate > > to the kernel (and thus the system security policy) the permission to > > interpret/execute scripts or other files containing what can be seen as > > commands. > > > > This third patch series mainly differ from the previous one by relying > > on the new openat2(2) system call to get rid of the undefined behavior > > of the open(2) flags. Thus, the previous O_MAYEXEC flag is now replaced > > with the new RESOLVE_MAYEXEC flag and benefits from the openat2(2) > > strict check of this kind of flags. > > My only strong upfront objection is with this being a RESOLVE_ flag. > > RESOLVE_ flags have a specific meaning (they generally apply to all > components, and affect the rules of path resolution). RESOLVE_MAYEXEC > does neither of these things and so seems out of place among the other > RESOLVE_ flags. > > I would argue this should be an O_ flag, but not supported for the I agree. Christian