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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4D1A0C433FE for ; Sat, 2 Oct 2021 21:47:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 280B561B23 for ; Sat, 2 Oct 2021 21:47:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234093AbhJBVtR (ORCPT ); Sat, 2 Oct 2021 17:49:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47790 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234069AbhJBVtQ (ORCPT ); Sat, 2 Oct 2021 17:49:16 -0400 Received: from mail-wm1-x331.google.com (mail-wm1-x331.google.com [IPv6:2a00:1450:4864:20::331]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 554F3C0613EC for ; Sat, 2 Oct 2021 14:47:30 -0700 (PDT) Received: by mail-wm1-x331.google.com with SMTP id b192so9888490wmb.2 for ; Sat, 02 Oct 2021 14:47:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rammhold-de.20210112.gappssmtp.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=DsMQk+8XXK1QsERSjLKDCEcVwg6XJ78+oxDV4RX+0p8=; b=MuS1vyAXNZRsOTxEBMpN7525qbmZsfsMfBl8tK4fsejdN07wZjhlezUBmQAbb9CblL wyf8IPNUZwgGUGeRcgf2fJRLTZ2RUP6Fd3KGvnDNlxHMINk9BuXpSIWKOmyOBMHVAOtR g7brUyYpEcQToTIV4Rzx/wTQ50y/2N3j/z68bIDfN0S6spafac5Y06tdOUwewj66Kkz2 3GV9CwRNgNYaLXU5qe/UrsH+jLqrsh/rMpV5a5T9y8GmmH2GnnnW1P3iPEkvIRsTffiU xnlEUqr85xK2DQGAs+eSMshhBOkVaGZ8PP0p0Xxsxrnc8PaZsxzMrIhSkB1wujHS/WkU VmaA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=DsMQk+8XXK1QsERSjLKDCEcVwg6XJ78+oxDV4RX+0p8=; b=cTxZtY1fDh6J0nBN+h7G4zdFPfPfhBDotuqHIoqw9LN9TpzqxhMH2NhsLnIYgnwcmi nUDd8zKtTClqiQ9walHiv2+F5XgAglGzlYVdlibef8cGAQmLCUP1nKuUNOBi53ortaLG gkTmU3ro8lH66c2Vtz8KY0zhkHGFAVY5n8t2L7maIXwUyqpARmCTCfZ+WpVNVlNPlcYh rTZ3iM5S14N2bMzAUSLf6XKzSbLc61/8K4h06MUADgCYw1VYBF3wYhrmppjdHof1yCV2 ShL+1cQABixIja4hZX1hUUreNmxIWM+n7myoxAtEO7YA1yXDZXstLGyeWLZeOEs3Bt95 wAag== X-Gm-Message-State: AOAM530zWLt22DdmyjgC4lgHhA6RoEqSNbFc89o1VDh3aayEmMBjatd5 6KryUZQMv0smHlhF561jMmIK9w== X-Google-Smtp-Source: ABdhPJwdYX14ToIr9FfRr/UP9/URxjMCG5/550hRz7VmbwRlxzR5s/s0klM9Dzz4ZV2ijUyONK3MYg== X-Received: by 2002:a7b:c24c:: with SMTP id b12mr985862wmj.173.1633211248812; Sat, 02 Oct 2021 14:47:28 -0700 (PDT) Received: from localhost ([2a00:e67:5c9:a:5621:d377:9a16:5c6c]) by smtp.gmail.com with ESMTPSA id x9sm9407532wrv.82.2021.10.02.14.47.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 02 Oct 2021 14:47:27 -0700 (PDT) Date: Sat, 2 Oct 2021 23:47:25 +0200 From: Andreas Rammhold To: Mimi Zohar Cc: Ahmad Fatoum , James Bottomley , Jarkko Sakkinen , David Howells , James Morris , "Serge E. Hallyn" , Sumit Garg , linux-integrity@vger.kernel.org, keyrings@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] KEYS: trusted: Fix trusted key backends when building as module Message-ID: <20211002214725.fqmtbfjwtlom745c@wrt> References: <20210730012822.3460913-1-andreas@rammhold.de> <0d42a11a-0117-49a9-d2c9-bc6cc405235d@pengutronix.de> <20210927085104.vq42feghtaqiv6ni@wrt> <856359f263575f01d0ce2fcf8f042321f750b38c.camel@linux.ibm.com> <20210927200835.wvazk73cek3t5tkf@wrt> <2ad2c536367028ef6d9300745586a123cb13d9f1.camel@linux.ibm.com> <20210927205521.7c4psu4vz5eoyfnf@wrt> <81602197662f3e6d032103bd1ac3690342544b7e.camel@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <81602197662f3e6d032103bd1ac3690342544b7e.camel@linux.ibm.com> Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org On 17:31 27.09.21, Mimi Zohar wrote: > On Mon, 2021-09-27 at 22:55 +0200, Andreas Rammhold wrote: > > On 16:33 27.09.21, Mimi Zohar wrote: > > > On Mon, 2021-09-27 at 22:08 +0200, Andreas Rammhold wrote: > > > > On 07:27 27.09.21, Mimi Zohar wrote: > > > > > On Mon, 2021-09-27 at 10:51 +0200, Andreas Rammhold wrote: > > > > > > On 09:47 13.09.21, Ahmad Fatoum wrote: > > > > > > > Dear trusted key maintainers, > > > > > > > > > > > > > > On 30.07.21 03:28, Andreas Rammhold wrote: > > > > > > > > Before this commit the kernel could end up with no trusted key sources > > > > > > > > even though both of the currently supported backends (TPM and TEE) were > > > > > > > > compiled as modules. This manifested in the trusted key type not being > > > > > > > > registered at all. > > > > > > > > > > > > > > > > When checking if a CONFIG_… preprocessor variable is defined we only > > > > > > > > test for the builtin (=y) case and not the module (=m) case. By using > > > > > > > > the IS_REACHABLE() macro we do test for both cases. > > > > > > > > > > > > > > > > Fixes: 5d0682be3189 ("KEYS: trusted: Add generic trusted keys framework") > > > > > > > > Signed-off-by: Andreas Rammhold > > > > > > > > Reviewed-by: Jarkko Sakkinen > > > > > > > Does anyone intend to pick this up? > > > > > > > > > > > > Did this end up in any tree by now? I am wondering if I should resend > > > > > > the patch instead. Perhaps it was just overlooked? > > > > > > > > > > For EVM environments only using trusted and encrypted keys, not file > > > > > signatures, the trusted key is needed to decrypt the "master" key in > > > > > order to verify kernel modules. > > > > > > > > So what you are saying is that right now (before this patch & after this > > > > patch) you could compile a kernel that wouldn't be able to load any > > > > modules when the trusted keychain part is built as module? > > > > > > Before this patch, trusted and encrypted keys are builtin, so verifying > > > kernel modules with security.evm containing an EVM hmac would succeed. > > > Afterwards it would fail, as there's a dependency on the trusted key to > > > verify the integrity of the trusted key module. > > > > But building with =m was a valid configuration which is the original > > reason for me submitting the patch. So perhaps this should not be > > allowed to be a module then? > > My mistake. Trusted and encrypted key types have always been defined > as tristate. Only when EVM selects encrypted keys, and by extension > trusted keys, are they builtin. So how do we go about this patch? Building the TPM support as module has broken actually using the trusted backend. This patch fixes that while still allowing it to be a builtin. If there is some configuration there a module isn't acceptable I am sure that is handled within Kconfig? Andi