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=-6.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 75A4DC4363D for ; Wed, 23 Sep 2020 23:05:53 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 07D0D20759 for ; Wed, 23 Sep 2020 23:05:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="waPeeiCl"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="muj4KSg6" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 07D0D20759 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=m0t+SQ8b5GHFmHMkuYOS35vo88tkzYd3ZUFLvY7Bj7Q=; b=waPeeiClUIMFlkMpFgXVHFui6 FHq0yOooPnIhjacNocML7wVFTUN+lz8Lf9vMO9L9Wu1eMR7n/87o77MElpU1OfObHFzQux+fyVgXI LyAOs2ezHIS4RZSdcQOmzQ/YmmnJi/eEEEHpVuTJjAZYDNuYO7+7GMlKIz660EmdCZqNT1dUgzIQc ZK0sQLDnvLx/k+mR+fgKLgTeBQdL1lhPeJ0ewzvX83oXXgrBAG/nVPa1APcS+er9B72delYy3np5z Jfngv2EBDns6RQPcHfYsqEVJiHXyIwyMDXXy4Xe249UTQmdlLr/jbfZUejYlCmBlWqMTg7d82gM1G AO+YRUhMw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kLDo7-0006R1-57; Wed, 23 Sep 2020 23:04:15 +0000 Received: from linux.microsoft.com ([13.77.154.182]) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kLDo4-0006Q6-JZ for linux-arm-kernel@lists.infradead.org; Wed, 23 Sep 2020 23:04:13 +0000 Received: from [192.168.254.38] (unknown [47.187.206.220]) by linux.microsoft.com (Postfix) with ESMTPSA id 8074320B7179; Wed, 23 Sep 2020 16:04:09 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 8074320B7179 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1600902250; bh=HgpNPjY5iVu1CzxgcR4kgt+n2CI09GHM7/xa0p1o1Kk=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=muj4KSg6D89EDGio3heOxHCQwEdt6gWLUvMQcKlmrgOQqUz62EUPYL8kaIGhY51c7 BiX3Nbq3xO6O7AV7JtpP/RXJguNQGwEe7nrqG4qvPO8M3K1jLBNuvwOX52gI+DcYSx kyoUN+2J9pxrSBa9emDc+4CJsNIRwh9UwZhyvp0k= Subject: Re: [PATCH v2 0/4] [RFC] Implement Trampoline File Descriptor To: Pavel Machek References: <210d7cd762d5307c2aa1676705b392bd445f1baa> <20200922215326.4603-1-madvenka@linux.microsoft.com> <20200923084232.GB30279@amd> <34257bc9-173d-8ef9-0c97-fb6bd0f69ecb@linux.microsoft.com> <20200923205156.GA12034@duo.ucw.cz> From: "Madhavan T. Venkataraman" Message-ID: Date: Wed, 23 Sep 2020 18:04:08 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200923205156.GA12034@duo.ucw.cz> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200923_190412_781075_5F2AAB2F X-CRM114-Status: GOOD ( 19.96 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: fweimer@redhat.com, mark.rutland@arm.com, kernel-hardening@lists.openwall.com, linux-api@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, oleg@redhat.com, mic@digikod.net, linux-security-module@vger.kernel.org, David.Laight@ACULAB.COM, luto@kernel.org, linux-fsdevel@vger.kernel.org, linux-integrity@vger.kernel.org, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 9/23/20 3:51 PM, Pavel Machek wrote: > Hi! > >>>> Scenario 2 >>>> ---------- >>>> >>>> We know what code we need in advance. User trampolines are a good example of >>>> this. It is possible to define such code statically with some help from the >>>> kernel. >>>> >>>> This RFC addresses (2). (1) needs a general purpose trusted code generator >>>> and is out of scope for this RFC. >>> >>> This is slightly less crazy talk than introduction talking about holes >>> in W^X. But it is very, very far from normal Unix system, where you >>> have selection of interpretters to run your malware on (sh, python, >>> awk, emacs, ...) and often you can even compile malware from sources. >>> >>> And as you noted, we don't have "a general purpose trusted code >>> generator" for our systems. >>> >>> I believe you should simply delete confusing "introduction" and >>> provide details of super-secure system where your patches would be >>> useful, instead. >> >> This RFC talks about converting dynamic code (which cannot be authenticated) >> to static code that can be authenticated using signature verification. That >> is the scope of this RFC. >> >> If I have not been clear before, by dynamic code, I mean machine code that is >> dynamic in nature. Scripts are beyond the scope of this RFC. >> >> Also, malware compiled from sources is not dynamic code. That is orthogonal >> to this RFC. If such malware has a valid signature that the kernel permits its >> execution, we have a systemic problem. >> >> I am not saying that script authentication or compiled malware are not problems. >> I am just saying that this RFC is not trying to solve all of the security problems. >> It is trying to define one way to convert dynamic code to static code to address >> one class of problems. > > Well, you don't have to solve all problems at once. > > But solutions have to exist, and AFAIK in this case they don't. You > are armoring doors, but ignoring open windows. > I am afraid I don't agree that the other open security issues must be addressed for this RFC to make sense. If you think that any of those issues actually has a bad interaction/intersection with this RFC, let me know how and I will address it. > Or very probably you are thinking about something different than > normal desktop distros (Debian 10). Because on my systems, I have > python, gdb and gcc... > > It would be nice to specify what other pieces need to be present for > this to make sense -- because it makes no sense on Debian 10. > Since this RFC pertains to converting dynamic machine code to static code, it has nothing to do with the other items you have mentioned. I am not disagreeing that the other items need to be addressed. But they are orthogonal. Madhavan _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel