From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751800AbdKQSKU (ORCPT ); Fri, 17 Nov 2017 13:10:20 -0500 Received: from mail-wm0-f67.google.com ([74.125.82.67]:46909 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751436AbdKQSKM (ORCPT ); Fri, 17 Nov 2017 13:10:12 -0500 X-Google-Smtp-Source: AGs4zMb4Ck1/63V/o7NG9nxEZsn7WYA1fqEcqVcWcKhSKazfz4oBculXYIQdvZETlvuS2RADbzCcaw== Subject: Re: [RFC PATCH] tpm: don't return -EINVAL if TPM command validation fails To: Jason Gunthorpe Cc: linux-kernel@vger.kernel.org, Jarkko Sakkinen , Peter Huewe , Philip Tricca , linux-integrity@vger.kernel.org, William Roberts References: <20171117100724.19257-1-javierm@redhat.com> <20171117165742.GH4276@ziepe.ca> <0e88aaa8-7d17-9cf7-c208-e31604a0e764@redhat.com> <20171117175834.GK4276@ziepe.ca> From: Javier Martinez Canillas Message-ID: <7f4e7c86-ef04-ea41-892f-1183a1d44a7b@redhat.com> Date: Fri, 17 Nov 2017 19:10:09 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: <20171117175834.GK4276@ziepe.ca> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/17/2017 06:58 PM, Jason Gunthorpe wrote: > On Fri, Nov 17, 2017 at 06:56:09PM +0100, Javier Martinez Canillas wrote: > >> Yes, the problem with that is user-space not having enough information about >> what went wrong. Right now the TCTI layer just reports TSS2_BASE_RC_IO_ERROR >> in this case and can't be blamed. > > Well, if you care about the differnce between a transport failure and > a kernel rejection due to validation, then it needs to report a > different code :) > Fair enough, the hard part I guess would be to decide which errno codes to use that could better map to the actual TPM_RC_COMMAND_{CODE,SIZE} response codes. I'll give some thought to this and also discuss with the tpm2 tools/tss folks. >>> Regarding your specific issue, can you make the command you want to >>> use validate? Would that make sense? >> >> Sorry, I'm not sure to understand what you meant. Could you please elaborate? > > Make it so tpm_validate will accept the command being sent. > Right, that's what I understood indeed but wanted to be sure. The problem with that approach is that would not scale. Since this particular TPM2 doesn't have support for the TPM2_EncryptDecrypt2 command, but some chips may not support others commands. So I rather prefer to have a consistent way for the kernel to report when a command is found to not be supported and user-space to understand it. > Jason > Best regards, -- Javier Martinez Canillas Software Engineer - Desktop Hardware Enablement Red Hat