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=-0.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=unavailable 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 63C81C65BAE for ; Thu, 13 Dec 2018 05:22:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 20E6820873 for ; Thu, 13 Dec 2018 05:22:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 20E6820873 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726849AbeLMFWI convert rfc822-to-8bit (ORCPT ); Thu, 13 Dec 2018 00:22:08 -0500 Received: from mx1.redhat.com ([209.132.183.28]:44472 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726226AbeLMFWH (ORCPT ); Thu, 13 Dec 2018 00:22:07 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 624738E588; Thu, 13 Dec 2018 05:22:07 +0000 (UTC) Received: from oldenburg2.str.redhat.com (ovpn-116-82.ams2.redhat.com [10.36.116.82]) by smtp.corp.redhat.com (Postfix) with ESMTPS id CF8C85D9C7; Thu, 13 Dec 2018 05:22:02 +0000 (UTC) From: Florian Weimer To: Matthew Wilcox Cc: =?utf-8?Q?Micka=C3=ABl_Sala=C3=BCn?= , linux-kernel@vger.kernel.org, Al Viro , James Morris , Jonathan Corbet , Kees Cook , Matthew Garrett , Michael Kerrisk , =?utf-8?Q?Micka=C3=ABl_Sala=C3=BCn?= , Mimi Zohar , Philippe =?utf-8?Q?Tr=C3=A9buchet?= , Shuah Khan , Thibaut Sautereau , Vincent Strubel , Yves-Alexis Perez , kernel-hardening@lists.openwall.com, linux-api@vger.kernel.org, linux-security-module@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [RFC PATCH v1 0/5] Add support for O_MAYEXEC References: <20181212081712.32347-1-mic@digikod.net> <20181213030228.GM6830@bombadil.infradead.org> Date: Thu, 13 Dec 2018 06:22:00 +0100 In-Reply-To: <20181213030228.GM6830@bombadil.infradead.org> (Matthew Wilcox's message of "Wed, 12 Dec 2018 19:02:28 -0800") Message-ID: <87bm5qovbb.fsf@oldenburg2.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Thu, 13 Dec 2018 05:22:07 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Matthew Wilcox: > On Wed, Dec 12, 2018 at 09:17:07AM +0100, Mickaël Salaün wrote: >> The goal of this patch series is to control script interpretation. A >> new O_MAYEXEC flag used by sys_open() is added to enable userland script >> interpreter to delegate to the kernel (and thus the system security >> policy) the permission to interpret scripts or other files containing >> what can be seen as commands. > > I don't have a problem with the concept, but we're running low on O_ bits. > Does this have to be done before the process gets a file descriptor, > or could we have a new syscall? Since we're going to be changing the > interpreters anyway, it doesn't seem like too much of an imposition to > ask them to use: > > int verify_for_exec(int fd) > > instead of adding an O_MAYEXEC. Will this work for auditing? Maybe add an interface which explicitly upgrades O_PATH descriptors, and give that a separate flag argument? I suppose that would be more friendly to auditing. Thanks, Florian From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Weimer Subject: Re: [RFC PATCH v1 0/5] Add support for O_MAYEXEC Date: Thu, 13 Dec 2018 06:22:00 +0100 Message-ID: <87bm5qovbb.fsf@oldenburg2.str.redhat.com> References: <20181212081712.32347-1-mic@digikod.net> <20181213030228.GM6830@bombadil.infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Return-path: In-Reply-To: <20181213030228.GM6830@bombadil.infradead.org> (Matthew Wilcox's message of "Wed, 12 Dec 2018 19:02:28 -0800") Sender: linux-kernel-owner@vger.kernel.org To: Matthew Wilcox Cc: =?utf-8?Q?Micka=C3=ABl_Sala=C3=BCn?= , linux-kernel@vger.kernel.org, Al Viro , James Morris , Jonathan Corbet , Kees Cook , Matthew Garrett , Michael Kerrisk , =?utf-8?Q?Micka=C3=ABl_Sala=C3=BCn?= , Mimi Zohar , Philippe =?utf-8?Q?Tr=C3=A9buchet?= , Shuah Khan , Thibaut Sautereau , Vincent Strubel , Yves-Alexis Perez , kernel-hardening@lists.openwall.com, linux-api@vger.kernel.org, linux-security-module@vger.kernel.org, linux-fsdev List-Id: linux-api@vger.kernel.org * Matthew Wilcox: > On Wed, Dec 12, 2018 at 09:17:07AM +0100, Mickaël Salaün wrote: >> The goal of this patch series is to control script interpretation. A >> new O_MAYEXEC flag used by sys_open() is added to enable userland script >> interpreter to delegate to the kernel (and thus the system security >> policy) the permission to interpret scripts or other files containing >> what can be seen as commands. > > I don't have a problem with the concept, but we're running low on O_ bits. > Does this have to be done before the process gets a file descriptor, > or could we have a new syscall? Since we're going to be changing the > interpreters anyway, it doesn't seem like too much of an imposition to > ask them to use: > > int verify_for_exec(int fd) > > instead of adding an O_MAYEXEC. Will this work for auditing? Maybe add an interface which explicitly upgrades O_PATH descriptors, and give that a separate flag argument? I suppose that would be more friendly to auditing. Thanks, Florian