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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 EC478C43142 for ; Thu, 21 Jun 2018 20:53:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A296521D62 for ; Thu, 21 Jun 2018 20:53:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A296521D62 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.vnet.ibm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933569AbeFUUxx (ORCPT ); Thu, 21 Jun 2018 16:53:53 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:51658 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933421AbeFUUxv (ORCPT ); Thu, 21 Jun 2018 16:53:51 -0400 Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w5LKnTTe062518 for ; Thu, 21 Jun 2018 16:53:51 -0400 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0b-001b2d01.pphosted.com with ESMTP id 2jrk6hggej-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 21 Jun 2018 16:53:51 -0400 Received: from localhost by e06smtp05.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 21 Jun 2018 21:53:49 +0100 Received: from b06cxnps3074.portsmouth.uk.ibm.com (9.149.109.194) by e06smtp05.uk.ibm.com (192.168.101.135) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Thu, 21 Jun 2018 21:53:47 +0100 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w5LKrkWU28180712 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 21 Jun 2018 20:53:46 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 9347552059; Thu, 21 Jun 2018 21:53:44 +0100 (BST) Received: from dhcp-9-31-103-18.watson.ibm.com (unknown [9.31.103.18]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id EFF6A52057; Thu, 21 Jun 2018 21:53:43 +0100 (BST) Subject: Re: [PATCH v2 3/4] ima: Use tpm_chip_find() and access TPM functions using it From: Mimi Zohar To: Stefan Berger , linux-integrity@vger.kernel.org, jarkko.sakkinen@linux.intel.com Cc: jgg@ziepe.ca, linux-kernel@vger.kernel.org Date: Thu, 21 Jun 2018 16:53:45 -0400 In-Reply-To: <20180620204236.1572523-4-stefanb@linux.vnet.ibm.com> References: <20180620204236.1572523-1-stefanb@linux.vnet.ibm.com> <20180620204236.1572523-4-stefanb@linux.vnet.ibm.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.20.5 (3.20.5-1.fc24) Mime-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 18062120-0020-0000-0000-0000029D8004 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18062120-0021-0000-0000-000020E9DC07 Message-Id: <1529614425.23843.20.camel@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-06-21_09:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=3 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1805220000 definitions=main-1806210224 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2018-06-20 at 16:42 -0400, Stefan Berger wrote: > Rather than accessing the TPM functions using a NULL pointer, which > causes a lookup for a suitable chip every time, get a hold of a tpm_chip > and access the TPM functions using this chip. We call the tpm_chip > ima_tpm_chip and protect it, once initialization is done, using a > rw_semaphore called ima_tpm_chip_lock. > > Use ima_shutdown to release the tpm_chip. > > Signed-off-by: Stefan Berger > --- > security/integrity/ima/ima.h | 3 +++ > security/integrity/ima/ima_crypto.c | 12 ++++++++++-- > security/integrity/ima/ima_init.c | 19 ++++++++++++------- > security/integrity/ima/ima_queue.c | 7 +++++-- > 4 files changed, 30 insertions(+), 11 deletions(-) > > diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h > index 354bb5716ce3..53a88d578ca5 100644 > --- a/security/integrity/ima/ima.h > +++ b/security/integrity/ima/ima.h > @@ -24,6 +24,7 @@ > #include > #include > #include > +#include > #include > > #include "../integrity.h" > @@ -56,6 +57,8 @@ extern int ima_policy_flag; > extern int ima_used_chip; > extern int ima_hash_algo; > extern int ima_appraise; > +extern struct rw_semaphore ima_tpm_chip_lock; > +extern struct tpm_chip *ima_tpm_chip; ima_add_templatE_entry() synchronizes appending a measurement to the measurement list and extending the TPM by taking a lock.  Do we really need to introduce another lock? Mimi > > /* IMA event related data */ > struct ima_event_data { > diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c > index 4e085a17124f..da7715240476 100644 > --- a/security/integrity/ima/ima_crypto.c > +++ b/security/integrity/ima/ima_crypto.c > @@ -631,10 +631,18 @@ int ima_calc_buffer_hash(const void *buf, loff_t len, > > static void __init ima_pcrread(int idx, u8 *pcr) > { > + int result = 0; > + > + down_read(&ima_tpm_chip_lock); > + > if (!ima_used_chip) > - return; > + goto out; > + > + result = tpm_pcr_read(ima_tpm_chip, idx, pcr); > +out: > + up_read(&ima_tpm_chip_lock); > > - if (tpm_pcr_read(NULL, idx, pcr) != 0) > + if (result != 0) > pr_err("Error Communicating to TPM chip\n"); > } > > diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c > index 8a5258eb32b6..24db06c4f463 100644 > --- a/security/integrity/ima/ima_init.c > +++ b/security/integrity/ima/ima_init.c > @@ -28,6 +28,8 @@ > /* name for boot aggregate entry */ > static const char *boot_aggregate_name = "boot_aggregate"; > int ima_used_chip; > +struct rw_semaphore ima_tpm_chip_lock = __RWSEM_INITIALIZER(ima_tpm_chip_lock); > +struct tpm_chip *ima_tpm_chip; > > /* Add the boot aggregate to the IMA measurement list and extend > * the PCR register. > @@ -108,6 +110,13 @@ void __init ima_load_x509(void) > static int ima_shutdown(struct notifier_block *this, unsigned long action, > void *data) > { > + down_write(&ima_tpm_chip_lock); > + if (ima_tpm_chip) { > + tpm_chip_put(ima_tpm_chip); > + ima_tpm_chip = NULL; > + ima_used_chip = 0; > + } > + up_write(&ima_tpm_chip_lock); > return NOTIFY_DONE; > } > > @@ -118,19 +127,15 @@ static struct notifier_block ima_reboot_notifier = { > > int __init ima_init(void) > { > - u8 pcr_i[TPM_DIGEST_SIZE]; > int rc; > > register_reboot_notifier(&ima_reboot_notifier); > > - ima_used_chip = 0; > - rc = tpm_pcr_read(NULL, 0, pcr_i); > - if (rc == 0) > - ima_used_chip = 1; > + ima_tpm_chip = tpm_chip_find(); > > + ima_used_chip = (ima_tpm_chip != NULL); > if (!ima_used_chip) > - pr_info("No TPM chip found, activating TPM-bypass! (rc=%d)\n", > - rc); > + pr_info("No TPM chip found, activating TPM-bypass!\n"); > > rc = integrity_init_keyring(INTEGRITY_KEYRING_IMA); > if (rc) > diff --git a/security/integrity/ima/ima_queue.c b/security/integrity/ima/ima_queue.c > index 418f35e38015..6c9427939a28 100644 > --- a/security/integrity/ima/ima_queue.c > +++ b/security/integrity/ima/ima_queue.c > @@ -142,10 +142,13 @@ static int ima_pcr_extend(const u8 *hash, int pcr) > { > int result = 0; > > + down_read(&ima_tpm_chip_lock); > if (!ima_used_chip) > - return result; > + goto out; > > - result = tpm_pcr_extend(NULL, pcr, hash); > + result = tpm_pcr_extend(ima_tpm_chip, pcr, hash); > +out: > + up_read(&ima_tpm_chip_lock); > if (result != 0) > pr_err("Error Communicating to TPM chip, result: %d\n", result); > return result;