From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752455AbdAZMXW (ORCPT ); Thu, 26 Jan 2017 07:23:22 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:45540 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750998AbdAZMXV (ORCPT ); Thu, 26 Jan 2017 07:23:21 -0500 Subject: Re: [tpmdd-devel] [PATCH v6 1/2] tpm: implement TPM 2.0 capability to get active PCR banks To: Nayna Jain , tpmdd-devel@lists.sourceforge.net References: <1484931913-24909-1-git-send-email-nayna@linux.vnet.ibm.com> <1484931913-24909-2-git-send-email-nayna@linux.vnet.ibm.com> Cc: linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org From: Stefan Berger Date: Thu, 26 Jan 2017 07:23:15 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.1.1 MIME-Version: 1.0 In-Reply-To: <1484931913-24909-2-git-send-email-nayna@linux.vnet.ibm.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: 17012612-0016-0000-0000-000005FAB381 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00006501; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000200; SDB=6.00812951; UDB=6.00396526; IPR=6.00590366; BA=6.00005091; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00014057; XFM=3.00000011; UTC=2017-01-26 12:23:18 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17012612-0017-0000-0000-000036D4ED72 Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-01-26_08:,, 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-1701260125 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/20/2017 12:05 PM, 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 > Reviewed-by: Jarkko Sakkinen > --- > drivers/char/tpm/tpm.h | 5 ++++ > drivers/char/tpm/tpm2-cmd.c | 59 +++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 64 insertions(+) > > diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h > index 1ae9768..c291f19 100644 > --- a/drivers/char/tpm/tpm.h > +++ b/drivers/char/tpm/tpm.h > @@ -97,6 +97,7 @@ enum tpm2_return_codes { > }; > > enum tpm2_algorithms { > + TPM2_ALG_ERROR = 0x0000, > TPM2_ALG_SHA1 = 0x0004, > TPM2_ALG_KEYEDHASH = 0x0008, > TPM2_ALG_SHA256 = 0x000B, > @@ -127,6 +128,7 @@ enum tpm2_permanent_handles { > }; > > enum tpm2_capabilities { > + TPM2_CAP_PCRS = 5, > TPM2_CAP_TPM_PROPERTIES = 6, > }; > > @@ -187,6 +189,8 @@ 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 +549,5 @@ 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..0e000a3 100644 > --- a/drivers/char/tpm/tpm2-cmd.c > +++ b/drivers/char/tpm/tpm2-cmd.c > @@ -998,3 +998,62 @@ 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; > + 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; > + > + count = be32_to_cpup( > + (__be32 *)&buf.data[TPM_HEADER_SIZE + 5]); > + > + if (count > ARRAY_SIZE(chip->active_banks)) { > + rc = -ENODEV; > + goto out; > + } > + > + marker = &buf.data[TPM_HEADER_SIZE + 9]; Now that we are checking access to the returned buffer, we should do an additional check here: end = &buf.data[TPM_HEADER_SIZE + rc]; > + for (i = 0; i < count; i++) { if (marker + sizeof(pcr_selection) >= end) { rc = -EFAULT; goto out; } > + 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)) if (rc < 0 || count < ARRAY_SIZE(...)) I can send a separate patch for this. Let me know. > + chip->active_banks[count] = TPM2_ALG_ERROR; > + > + tpm_buf_destroy(&buf); > + > + return rc; > +}