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=-5.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,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 371B6C433E0 for ; Fri, 15 May 2020 08:44:14 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 81C3B2054F for ; Fri, 15 May 2020 08:44:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="fKScrmok" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 81C3B2054F 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-18814-kernel-hardening=archiver.kernel.org@lists.openwall.com Received: (qmail 9818 invoked by uid 550); 15 May 2020 08:44:06 -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 9792 invoked from network); 15 May 2020 08:44:05 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1589532233; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=+98viFOd9jTdpHCY3sUvt3t0b4J5Yg6795DHu7DfVIk=; b=fKScrmokPCuiEv3RuFPvqUqtSW4pRmkmMSR+m4lh38ZgD+He292FGbDa0d1vO+m+zQM/FS hZS2ZoMIm6vpaQmRVG+WTcp5H2ZGUlT6LGY28+K/tGKndmvV9ym5GKCV4EXnuQEpX8Wv68 TnnOhRJ7AnJGXiPknOKzEniP49FHPNI= X-MC-Unique: u_nUq3bSN8OR1tg-mmpQdg-1 From: Florian Weimer To: Kees Cook Cc: =?utf-8?Q?Micka=C3=ABl_Sala=C3=BCn?= , Al Viro , Aleksa Sarai , Andy Lutomirski , Mimi Zohar , Stephen Smalley , Christian Heimes , Deven Bowers , Tetsuo Handa , John Johansen , Kentaro Takeda , "Lev R. Oshvang ." , Alexei Starovoitov , Daniel Borkmann , Eric Chiang , James Morris , Jan Kara , Jann Horn , Jonathan Corbet , Lakshmi Ramasubramanian , Matthew Garrett , Matthew Wilcox , Michael Kerrisk , =?utf-8?Q?Micka=C3=ABl_Sala=C3=BCn?= , Philippe =?utf-8?Q?Tr=C3=A9buchet?= , Scott Shell , Sean Christopherson , Shuah Khan , Steve Dower , Steve Grubb , Thibaut Sautereau , Vincent Strubel , linux-kernel , kernel-hardening@lists.openwall.com, linux-api@vger.kernel.org, linux-integrity@vger.kernel.org, LSM List , Linux FS Devel Subject: Re: How about just O_EXEC? (was Re: [PATCH v5 3/6] fs: Enable to enforce noexec mounts or file exec through O_MAYEXEC) References: <20200505153156.925111-1-mic@digikod.net> <20200505153156.925111-4-mic@digikod.net> <202005131525.D08BFB3@keescook> <202005132002.91B8B63@keescook> <202005140830.2475344F86@keescook> <202005142343.D580850@keescook> Date: Fri, 15 May 2020 10:43:34 +0200 In-Reply-To: <202005142343.D580850@keescook> (Kees Cook's message of "Fri, 15 May 2020 01:01:32 -0700") Message-ID: <87a729wpu1.fsf@oldenburg2.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 * Kees Cook: > Maybe I've missed some earlier discussion that ruled this out, but I > couldn't find it: let's just add O_EXEC and be done with it. It actually > makes the execve() path more like openat2() and is much cleaner after > a little refactoring. Here are the results, though I haven't emailed it > yet since I still want to do some more testing: > https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git/log/?h=kspp/o_exec/v1 I think POSIX specifies O_EXEC in such a way that it does not confer read permissions. This seems incompatible with what we are trying to achieve here. Thanks, Florian