From patchwork Fri Jul 5 16:37:35 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 11033027 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 9A99B14F6 for ; Fri, 5 Jul 2019 16:41:03 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 85AF32892C for ; Fri, 5 Jul 2019 16:41:03 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 79FC628AFD; Fri, 5 Jul 2019 16:41:03 +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=ham 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 DD4C5289C0 for ; Fri, 5 Jul 2019 16:41:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728563AbfGEQlC (ORCPT ); Fri, 5 Jul 2019 12:41:02 -0400 Received: from lhrrgout.huawei.com ([185.176.76.210]:33057 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726302AbfGEQlC (ORCPT ); Fri, 5 Jul 2019 12:41:02 -0400 Received: from LHREML711-CAH.china.huawei.com (unknown [172.18.7.108]) by Forcepoint Email with ESMTP id 01758ED5E91E14B571A7; Fri, 5 Jul 2019 17:41:00 +0100 (IST) Received: from roberto-HP-EliteDesk-800-G2-DM-65W.huawei.com (10.204.65.154) by smtpsuk.huawei.com (10.201.108.34) with Microsoft SMTP Server (TLS) id 14.3.408.0; Fri, 5 Jul 2019 17:40:52 +0100 From: Roberto Sassu To: , , , CC: , , , , , , , , Roberto Sassu Subject: [PATCH] KEYS: trusted: allow module init if TPM is inactive or deactivated Date: Fri, 5 Jul 2019 18:37:35 +0200 Message-ID: <20190705163735.11539-1-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-Originating-IP: [10.204.65.154] X-CFilter-Loop: Reflected Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP Commit c78719203fc6 ("KEYS: trusted: allow trusted.ko to initialize w/o a TPM") allows the trusted module to be loaded even a TPM is not found to avoid module dependency problems. Unfortunately, this does not completely solve the issue, as there could be a case where a TPM is found but is not functional (the TPM commands return an error). Specifically, after the tpm_chip structure is returned by tpm_default_chip() in init_trusted(), the execution terminates after init_digests() returns -EFAULT (due to the fact that tpm_get_random() returns a positive value, but less than TPM_MAX_DIGEST_SIZE). This patch fixes the issue by ignoring the TPM_ERR_DEACTIVATED and TPM_ERR_DISABLED errors. Fixes: 240730437deb ("KEYS: trusted: explicitly use tpm_chip structure...") Signed-off-by: Roberto Sassu --- drivers/char/tpm/tpm.h | 2 -- include/linux/tpm.h | 3 +++ security/keys/trusted.c | 6 +++++- 3 files changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index e503ffc3aa39..a216ac396711 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -54,8 +54,6 @@ enum tpm_addr { #define TPM_WARN_RETRY 0x800 #define TPM_WARN_DOING_SELFTEST 0x802 -#define TPM_ERR_DEACTIVATED 0x6 -#define TPM_ERR_DISABLED 0x7 #define TPM_ERR_INVALID_POSTINIT 38 #define TPM_HEADER_SIZE 10 diff --git a/include/linux/tpm.h b/include/linux/tpm.h index 53c0ea9ec9df..efd3ccbb6aee 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -26,6 +26,9 @@ #define TPM_DIGEST_SIZE 20 /* Max TPM v1.2 PCR size */ #define TPM_MAX_DIGEST_SIZE SHA512_DIGEST_SIZE +#define TPM_ERR_DEACTIVATED 0x6 +#define TPM_ERR_DISABLED 0x7 + struct tpm_chip; struct trusted_key_payload; struct trusted_key_options; diff --git a/security/keys/trusted.c b/security/keys/trusted.c index 9a94672e7adc..430d85090b3b 100644 --- a/security/keys/trusted.c +++ b/security/keys/trusted.c @@ -389,6 +389,10 @@ static int pcrlock(const int pcrnum) if (!capable(CAP_SYS_ADMIN)) return -EPERM; + /* This can happen if the TPM is inactive. */ + if (!digests) + return -EINVAL; + return tpm_pcr_extend(chip, pcrnum, digests) ? -EINVAL : 0; } @@ -1233,7 +1237,7 @@ static int __init init_digests(void) int i; ret = tpm_get_random(chip, digest, TPM_MAX_DIGEST_SIZE); - if (ret < 0) + if (ret < 0 || ret == TPM_ERR_DEACTIVATED || ret == TPM_ERR_DISABLED) return ret; if (ret < TPM_MAX_DIGEST_SIZE) return -EFAULT;