From patchwork Tue Oct 30 15:47:06 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 10661153 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0791D13B5 for ; Tue, 30 Oct 2018 15:50:42 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EB8782A790 for ; Tue, 30 Oct 2018 15:50:41 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E98C22A7DB; Tue, 30 Oct 2018 15:50:41 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9DE672A7D2 for ; Tue, 30 Oct 2018 15:50:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727596AbeJaAoR (ORCPT ); Tue, 30 Oct 2018 20:44:17 -0400 Received: from lhrrgout.huawei.com ([185.176.76.210]:32703 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725853AbeJaAoQ (ORCPT ); Tue, 30 Oct 2018 20:44:16 -0400 Received: from lhreml703-cah.china.huawei.com (unknown [172.18.7.106]) by Forcepoint Email with ESMTP id A24C8950F1832; Tue, 30 Oct 2018 15:50:12 +0000 (GMT) Received: from roberto-HP-EliteDesk-800-G2-DM-65W.huawei.com (10.204.65.153) by smtpsuk.huawei.com (10.201.108.44) with Microsoft SMTP Server (TLS) id 14.3.408.0; Tue, 30 Oct 2018 15:50:05 +0000 From: Roberto Sassu To: , CC: , , , , Roberto Sassu Subject: [PATCH v3 0/5] tpm: retrieve digest size of unknown algorithms from TPM Date: Tue, 30 Oct 2018 16:47:06 +0100 Message-ID: <20181030154711.2782-1-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-Originating-IP: [10.204.65.153] X-CFilter-Loop: Reflected Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP The TPM driver currently relies on the crypto subsystem to determine the digest size of supported TPM algorithms. In the future, TPM vendors might implement new algorithms in their chips, and those algorithms might not be supported by the crypto subsystem. Usually, vendors provide patches for the new hardware, and likely the crypto subsystem will be updated before the new algorithm is introduced. However, old kernels might be updated later, after patches are included in the mainline kernel. This would leave the opportunity for attackers to misuse PCRs, as PCR banks with an unknown algorithm are not extended. This patch set provides a long term solution for this issue. If a TPM algorithm is not known by the crypto subsystem, the TPM driver retrieves the digest size from the TPM with a PCR read. All the PCR banks are extended, even if the algorithm is not yet supported by the crypto subsystem. PCR bank information (TPM algorithm ID, digest size, crypto subsystem ID) is stored in the tpm_chip structure and available for users of the TPM driver. Changelog v2: - change the end marker of the active_banks array - check digest size from output of PCR read command - remove count parameter from tpm_pcr_read() and tpm2_pcr_read() v1: - modify definition of tpm_pcr_read() - move hash algorithms and definition of tpm2_digest to include/linux/tpm.h Roberto Sassu (5): tpm: change the end marker of the active_banks array to zero tpm: rename and export tpm2_digest and tpm2_algorithms tpm: modify tpm_pcr_read() definition to pass a TPM hash algorithm tpm: retrieve digest size of unknown algorithms with PCR read tpm: ensure that output of PCR read contains the correct digest size drivers/char/tpm/tpm-interface.c | 19 ++++-- drivers/char/tpm/tpm.h | 18 ++---- drivers/char/tpm/tpm2-cmd.c | 99 +++++++++++++++++++++-------- include/linux/tpm.h | 30 ++++++++- include/linux/tpm_eventlog.h | 9 +-- security/integrity/ima/ima_crypto.c | 10 +-- 6 files changed, 122 insertions(+), 63 deletions(-)