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 3ECB7C43331 for ; Fri, 6 Sep 2019 18:57:29 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 87A37208C3 for ; Fri, 6 Sep 2019 18:57:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 87A37208C3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernel-hardening-return-16860-kernel-hardening=archiver.kernel.org@lists.openwall.com Received: (qmail 26065 invoked by uid 550); 6 Sep 2019 18:57:22 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Received: (qmail 26037 invoked from network); 6 Sep 2019 18:57:21 -0000 From: Florian Weimer To: Steve Grubb Cc: =?utf-8?Q?Micka=C3=ABl_Sala=C3=BCn?= , linux-kernel@vger.kernel.org, Aleksa Sarai , Alexei Starovoitov , Al Viro , Andy Lutomirski , Christian Heimes , Daniel Borkmann , Eric Chiang , 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 , Song Liu , Steve Dower , 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: [PATCH v2 0/5] Add support for O_MAYEXEC References: <20190906152455.22757-1-mic@digikod.net> <2989749.1YmIBkDdQn@x2> Date: Fri, 06 Sep 2019 20:57:00 +0200 In-Reply-To: <2989749.1YmIBkDdQn@x2> (Steve Grubb's message of "Fri, 06 Sep 2019 14:50:02 -0400") Message-ID: <87mufhckxv.fsf@oldenburg2.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.6.2 (mx1.redhat.com [10.5.110.66]); Fri, 06 Sep 2019 18:57:10 +0000 (UTC) * Steve Grubb: > Now with LD_AUDIT > $ LD_AUDIT=/home/sgrubb/test/openflags/strip-flags.so.0 strace ./test 2>&1 | grep passwd > openat(3, "passwd", O_RDONLY) = 4 > > No O_CLOEXEC flag. I think you need to explain in detail why you consider this a problem. With LD_PRELOAD and LD_AUDIT, you can already do anything, including scanning other loaded objects for a system call instruction and jumping to that (in case a security module in the kernel performs a PC check to confer additional privileges). Thanks, Florian