From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753156AbdASNka (ORCPT ); Thu, 19 Jan 2017 08:40:30 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:36898 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752728AbdASNf1 (ORCPT ); Thu, 19 Jan 2017 08:35:27 -0500 Subject: Re: [PATCH v4 1/2] tpm: implement TPM 2.0 capability to get active PCR banks To: Jarkko Sakkinen References: <1484729090-16012-1-git-send-email-nayna@linux.vnet.ibm.com> <1484729090-16012-2-git-send-email-nayna@linux.vnet.ibm.com> <20170118134522.ftikno7gy3vttv6w@intel.com> <587F7252.4070808@linux.vnet.ibm.com> <20170119104759.oqobziiuy7lqnzbf@intel.com> Cc: tpmdd-devel@lists.sourceforge.net, peterhuewe@gmx.de, tpmdd@selhorst.net, jgunthorpe@obsidianresearch.com, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org From: Nayna Date: Thu, 19 Jan 2017 19:04:44 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <20170119104759.oqobziiuy7lqnzbf@intel.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 17011913-0020-0000-0000-00000B1F5E3A X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00006461; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000199; SDB=6.00809810; UDB=6.00394548; IPR=6.00587163; BA=6.00005075; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00013980; XFM=3.00000011; UTC=2017-01-19 13:35:20 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17011913-0021-0000-0000-000059588755 Message-Id: <5880C074.9050401@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-01-19_04:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1612050000 definitions=main-1701190178 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/19/2017 04:17 PM, Jarkko Sakkinen wrote: > On Wed, Jan 18, 2017 at 07:19:06PM +0530, Nayna wrote: >> >> >> On 01/18/2017 07:15 PM, Jarkko Sakkinen wrote: >>> On Wed, Jan 18, 2017 at 03:44:49AM -0500, Nayna Jain wrote: >>>> This patch implements the TPM 2.0 capability TPM_CAP_PCRS to >>>> retrieve the active PCR banks from the TPM. This is needed >>>> to enable extending all active banks as recommended by TPM 2.0 >>>> TCG Specification. >>>> >>>> Signed-off-by: Nayna Jain >>>> --- >>>> drivers/char/tpm/tpm.h | 4 ++++ >>>> drivers/char/tpm/tpm2-cmd.c | 57 +++++++++++++++++++++++++++++++++++++++++++++ >>>> 2 files changed, 61 insertions(+) >>>> >>>> diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h >>>> index 1ae9768..dddd573 100644 >>>> --- a/drivers/char/tpm/tpm.h >>>> +++ b/drivers/char/tpm/tpm.h >>>> @@ -127,6 +127,7 @@ enum tpm2_permanent_handles { >>>> }; >>>> >>>> enum tpm2_capabilities { >>>> + TPM2_CAP_PCRS = 5, >>>> TPM2_CAP_TPM_PROPERTIES = 6, >>>> }; >>>> >>>> @@ -187,6 +188,8 @@ struct tpm_chip { >>>> >>>> const struct attribute_group *groups[3]; >>>> unsigned int groups_cnt; >>>> + >>>> + u16 active_banks[7]; >>>> #ifdef CONFIG_ACPI >>>> acpi_handle acpi_dev_handle; >>>> char ppi_version[TPM_PPI_VERSION_LEN + 1]; >>>> @@ -545,4 +548,5 @@ int tpm2_auto_startup(struct tpm_chip *chip); >>>> void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type); >>>> unsigned long tpm2_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal); >>>> int tpm2_probe(struct tpm_chip *chip); >>>> +ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip); >>>> #endif >>>> diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c >>>> index 6eda239..75a7546 100644 >>>> --- a/drivers/char/tpm/tpm2-cmd.c >>>> +++ b/drivers/char/tpm/tpm2-cmd.c >>>> @@ -998,3 +998,60 @@ int tpm2_auto_startup(struct tpm_chip *chip) >>>> rc = -ENODEV; >>>> return rc; >>>> } >>>> + >>>> +struct tpm2_pcr_selection { >>>> + __be16 hash_alg; >>>> + u8 size_of_select; >>>> + u8 pcr_select[3]; >>>> +} __packed; >>>> + >>>> +/** >>>> + * tpm2_get_pcr_allocation() - get TPM active PCR banks. >>>> + * >>>> + * @chip: TPM chip to use. >>>> + * >>>> + * Return: Same as with tpm_transmit_cmd. >>>> + */ >>>> +ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip) >>>> +{ >>>> + struct tpm2_pcr_selection pcr_selection; >>>> + struct tpm_buf buf; >>>> + void *marker; >>>> + unsigned int count = 0; >>> >>> You shouldn't initialize 'count'. >> >> It is initialized for reason below: >> >>> >>>> + int rc; >>>> + int i; >>>> + >>>> + rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY); >>>> + if (rc) >>>> + return rc; >>>> + >>>> + tpm_buf_append_u32(&buf, TPM2_CAP_PCRS); >>>> + tpm_buf_append_u32(&buf, 0); >>>> + tpm_buf_append_u32(&buf, 1); >>>> + >>>> + rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, 0, >>>> + "get tpm pcr allocation"); >>>> + if (rc < 0) >>>> + goto out; >> >> if tpm_transmit_cmd()fails, it jumps to out: >> where count is used in if(..). > > Why the out label is placed there and not after? Since tpm2_get_pcr_allocation() returns from here as failure, chip->active_banks doesn't get anytime initialized. By placing it there, for failure, chip->active_bank[0] is initialized to 0. Then its later use like in tpm_pcr_extend(), it loops on this array till there is a value "0"(considered as invalid) or reaches max size of array. > >> >> Thanks & Regards, >> - Nayna >> >>>> + >>>> + count = be32_to_cpup( >>>> + (__be32 *)&buf.data[TPM_HEADER_SIZE + 5]); >>>> + >>>> + if (count > ARRAY_SIZE(chip->active_banks)) >>>> + return -ENODEV; > > Hey, here's a regression (didn't notice it last time). You > nee to call tpm_buf_destroy(). Oh!! Yes, Thanks !!. I will fix this with: rc = -ENODEV; goto out; Thanks & Regards - Nayna > > >>>> + >>>> + marker = &buf.data[TPM_HEADER_SIZE + 9]; >>>> + for (i = 0; i < count; i++) { >>>> + memcpy(&pcr_selection, marker, sizeof(pcr_selection)); >>>> + chip->active_banks[i] = be16_to_cpu(pcr_selection.hash_alg); >>>> + marker = marker + sizeof(struct tpm2_pcr_selection); >>>> + } >>>> + >>>> +out: >>>> + if (count < ARRAY_SIZE(chip->active_banks)) >>>> + chip->active_banks[count] = 0; >>>> + >>>> + tpm_buf_destroy(&buf); >>>> + >>>> + return rc; >>>> +} >>>> -- >>>> 2.5.0 >>> >>> Otherwise, >>> >>> Reviewed-by: Jarkko Sakkinen >>> >>> /Jarkko >>> >> > > /Jarkko >