From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1035916AbdEXVkV (ORCPT ); Wed, 24 May 2017 17:40:21 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:40285 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1033533AbdEXVkE (ORCPT ); Wed, 24 May 2017 17:40:04 -0400 From: Stefan Berger To: jarkko.sakkinen@linux.intel.com, tpmdd-devel@lists.sourceforge.net Cc: linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, jgunthorpe@obsidianresearch.com, Stefan Berger Subject: [PATCH v6 3/3] tpm: vtpm_proxy: Prevent userspace from sending driver command Date: Wed, 24 May 2017 17:39:41 -0400 X-Mailer: git-send-email 2.5.5 In-Reply-To: <1495661981-27249-1-git-send-email-stefanb@linux.vnet.ibm.com> References: <1495661981-27249-1-git-send-email-stefanb@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 17052421-0040-0000-0000-00000348C2F6 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007112; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000212; SDB=6.00865133; UDB=6.00429542; IPR=6.00644914; BA=6.00005372; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00015571; XFM=3.00000015; UTC=2017-05-24 21:40:01 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17052421-0041-0000-0000-0000073CF841 Message-Id: <1495661981-27249-4-git-send-email-stefanb@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-05-24_14:,, 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=8.0.1-1703280000 definitions=main-1705240115 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org To prevent userspace from sending the TPM driver command to set the locality, we need to check every command that is sent from user space. To distinguish user space commands from internally sent commands we introduce an additional state flag STATE_DRIVER_COMMAND that is set while the driver sends this command. Similar to the TPM 2 space commands we return an error code when this command is detected. Signed-off-by: Stefan Berger --- drivers/char/tpm/tpm_vtpm_proxy.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c index 66024bf..1d877cc 100644 --- a/drivers/char/tpm/tpm_vtpm_proxy.c +++ b/drivers/char/tpm/tpm_vtpm_proxy.c @@ -43,6 +43,7 @@ struct proxy_dev { #define STATE_OPENED_FLAG BIT(0) #define STATE_WAIT_RESPONSE_FLAG BIT(1) /* waiting for emulator response */ #define STATE_REGISTERED_FLAG BIT(2) +#define STATE_DRIVER_COMMAND BIT(3) /* sending a driver specific command */ size_t req_len; /* length of queued TPM request */ size_t resp_len; /* length of queued TPM response */ @@ -299,6 +300,28 @@ static int vtpm_proxy_tpm_op_recv(struct tpm_chip *chip, u8 *buf, size_t count) return len; } +static int vtpm_proxy_is_driver_command(struct tpm_chip *chip, + u8 *buf, size_t count) +{ + struct tpm_input_header *hdr = (struct tpm_input_header *)buf; + + if (count < sizeof(struct tpm_input_header)) + return 0; + + if (chip->flags & TPM_CHIP_FLAG_TPM2) { + switch (be32_to_cpu(hdr->ordinal)) { + case TPM2_CC_SET_LOCALITY: + return 1; + } + } else { + switch (be32_to_cpu(hdr->ordinal)) { + case TPM_ORD_SET_LOCALITY: + return 1; + } + } + return 0; +} + /* * Called when core TPM driver forwards TPM requests to 'server side'. * @@ -321,6 +344,10 @@ static int vtpm_proxy_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t count) return -EIO; } + if (!(proxy_dev->state & STATE_DRIVER_COMMAND) && + vtpm_proxy_is_driver_command(chip, buf, count)) + return -EFAULT; + mutex_lock(&proxy_dev->buf_lock); if (!(proxy_dev->state & STATE_OPENED_FLAG)) { @@ -376,6 +403,7 @@ static int vtpm_proxy_request_locality(struct tpm_chip *chip, int locality) struct tpm_buf buf; int rc; const struct tpm_output_header *header; + struct proxy_dev *proxy_dev = dev_get_drvdata(&chip->dev); if (chip->flags & TPM_CHIP_FLAG_TPM2) rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, @@ -387,9 +415,14 @@ static int vtpm_proxy_request_locality(struct tpm_chip *chip, int locality) return rc; tpm_buf_append_u8(&buf, locality); + proxy_dev->state |= STATE_DRIVER_COMMAND; + rc = tpm_transmit_cmd(chip, NULL, buf.data, tpm_buf_length(&buf), 0, TPM_TRANSMIT_UNLOCKED | TPM_TRANSMIT_RAW, "attempting to set locality"); + + proxy_dev->state &= ~STATE_DRIVER_COMMAND; + if (rc < 0) { locality = rc; goto out; -- 2.4.3 From mboxrd@z Thu Jan 1 00:00:00 1970 From: stefanb@linux.vnet.ibm.com (Stefan Berger) Date: Wed, 24 May 2017 17:39:41 -0400 Subject: [PATCH v6 3/3] tpm: vtpm_proxy: Prevent userspace from sending driver command In-Reply-To: <1495661981-27249-1-git-send-email-stefanb@linux.vnet.ibm.com> References: <1495661981-27249-1-git-send-email-stefanb@linux.vnet.ibm.com> Message-ID: <1495661981-27249-4-git-send-email-stefanb@linux.vnet.ibm.com> To: linux-security-module@vger.kernel.org List-Id: linux-security-module.vger.kernel.org To prevent userspace from sending the TPM driver command to set the locality, we need to check every command that is sent from user space. To distinguish user space commands from internally sent commands we introduce an additional state flag STATE_DRIVER_COMMAND that is set while the driver sends this command. Similar to the TPM 2 space commands we return an error code when this command is detected. Signed-off-by: Stefan Berger --- drivers/char/tpm/tpm_vtpm_proxy.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c index 66024bf..1d877cc 100644 --- a/drivers/char/tpm/tpm_vtpm_proxy.c +++ b/drivers/char/tpm/tpm_vtpm_proxy.c @@ -43,6 +43,7 @@ struct proxy_dev { #define STATE_OPENED_FLAG BIT(0) #define STATE_WAIT_RESPONSE_FLAG BIT(1) /* waiting for emulator response */ #define STATE_REGISTERED_FLAG BIT(2) +#define STATE_DRIVER_COMMAND BIT(3) /* sending a driver specific command */ size_t req_len; /* length of queued TPM request */ size_t resp_len; /* length of queued TPM response */ @@ -299,6 +300,28 @@ static int vtpm_proxy_tpm_op_recv(struct tpm_chip *chip, u8 *buf, size_t count) return len; } +static int vtpm_proxy_is_driver_command(struct tpm_chip *chip, + u8 *buf, size_t count) +{ + struct tpm_input_header *hdr = (struct tpm_input_header *)buf; + + if (count < sizeof(struct tpm_input_header)) + return 0; + + if (chip->flags & TPM_CHIP_FLAG_TPM2) { + switch (be32_to_cpu(hdr->ordinal)) { + case TPM2_CC_SET_LOCALITY: + return 1; + } + } else { + switch (be32_to_cpu(hdr->ordinal)) { + case TPM_ORD_SET_LOCALITY: + return 1; + } + } + return 0; +} + /* * Called when core TPM driver forwards TPM requests to 'server side'. * @@ -321,6 +344,10 @@ static int vtpm_proxy_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t count) return -EIO; } + if (!(proxy_dev->state & STATE_DRIVER_COMMAND) && + vtpm_proxy_is_driver_command(chip, buf, count)) + return -EFAULT; + mutex_lock(&proxy_dev->buf_lock); if (!(proxy_dev->state & STATE_OPENED_FLAG)) { @@ -376,6 +403,7 @@ static int vtpm_proxy_request_locality(struct tpm_chip *chip, int locality) struct tpm_buf buf; int rc; const struct tpm_output_header *header; + struct proxy_dev *proxy_dev = dev_get_drvdata(&chip->dev); if (chip->flags & TPM_CHIP_FLAG_TPM2) rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, @@ -387,9 +415,14 @@ static int vtpm_proxy_request_locality(struct tpm_chip *chip, int locality) return rc; tpm_buf_append_u8(&buf, locality); + proxy_dev->state |= STATE_DRIVER_COMMAND; + rc = tpm_transmit_cmd(chip, NULL, buf.data, tpm_buf_length(&buf), 0, TPM_TRANSMIT_UNLOCKED | TPM_TRANSMIT_RAW, "attempting to set locality"); + + proxy_dev->state &= ~STATE_DRIVER_COMMAND; + if (rc < 0) { locality = rc; goto out; -- 2.4.3 -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo at vger.kernel.org More majordomo info@ http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Berger Subject: [PATCH v6 3/3] tpm: vtpm_proxy: Prevent userspace from sending driver command Date: Wed, 24 May 2017 17:39:41 -0400 Message-ID: <1495661981-27249-4-git-send-email-stefanb@linux.vnet.ibm.com> References: <1495661981-27249-1-git-send-email-stefanb@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1495661981-27249-1-git-send-email-stefanb-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: tpmdd-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org, tpmdd-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Cc: linux-security-module-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: tpmdd-devel@lists.sourceforge.net To prevent userspace from sending the TPM driver command to set the locality, we need to check every command that is sent from user space. To distinguish user space commands from internally sent commands we introduce an additional state flag STATE_DRIVER_COMMAND that is set while the driver sends this command. Similar to the TPM 2 space commands we return an error code when this command is detected. Signed-off-by: Stefan Berger --- drivers/char/tpm/tpm_vtpm_proxy.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c index 66024bf..1d877cc 100644 --- a/drivers/char/tpm/tpm_vtpm_proxy.c +++ b/drivers/char/tpm/tpm_vtpm_proxy.c @@ -43,6 +43,7 @@ struct proxy_dev { #define STATE_OPENED_FLAG BIT(0) #define STATE_WAIT_RESPONSE_FLAG BIT(1) /* waiting for emulator response */ #define STATE_REGISTERED_FLAG BIT(2) +#define STATE_DRIVER_COMMAND BIT(3) /* sending a driver specific command */ size_t req_len; /* length of queued TPM request */ size_t resp_len; /* length of queued TPM response */ @@ -299,6 +300,28 @@ static int vtpm_proxy_tpm_op_recv(struct tpm_chip *chip, u8 *buf, size_t count) return len; } +static int vtpm_proxy_is_driver_command(struct tpm_chip *chip, + u8 *buf, size_t count) +{ + struct tpm_input_header *hdr = (struct tpm_input_header *)buf; + + if (count < sizeof(struct tpm_input_header)) + return 0; + + if (chip->flags & TPM_CHIP_FLAG_TPM2) { + switch (be32_to_cpu(hdr->ordinal)) { + case TPM2_CC_SET_LOCALITY: + return 1; + } + } else { + switch (be32_to_cpu(hdr->ordinal)) { + case TPM_ORD_SET_LOCALITY: + return 1; + } + } + return 0; +} + /* * Called when core TPM driver forwards TPM requests to 'server side'. * @@ -321,6 +344,10 @@ static int vtpm_proxy_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t count) return -EIO; } + if (!(proxy_dev->state & STATE_DRIVER_COMMAND) && + vtpm_proxy_is_driver_command(chip, buf, count)) + return -EFAULT; + mutex_lock(&proxy_dev->buf_lock); if (!(proxy_dev->state & STATE_OPENED_FLAG)) { @@ -376,6 +403,7 @@ static int vtpm_proxy_request_locality(struct tpm_chip *chip, int locality) struct tpm_buf buf; int rc; const struct tpm_output_header *header; + struct proxy_dev *proxy_dev = dev_get_drvdata(&chip->dev); if (chip->flags & TPM_CHIP_FLAG_TPM2) rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, @@ -387,9 +415,14 @@ static int vtpm_proxy_request_locality(struct tpm_chip *chip, int locality) return rc; tpm_buf_append_u8(&buf, locality); + proxy_dev->state |= STATE_DRIVER_COMMAND; + rc = tpm_transmit_cmd(chip, NULL, buf.data, tpm_buf_length(&buf), 0, TPM_TRANSMIT_UNLOCKED | TPM_TRANSMIT_RAW, "attempting to set locality"); + + proxy_dev->state &= ~STATE_DRIVER_COMMAND; + if (rc < 0) { locality = rc; goto out; -- 2.4.3 ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot