From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753413AbcHQEbY (ORCPT ); Wed, 17 Aug 2016 00:31:24 -0400 Received: from mga03.intel.com ([134.134.136.65]:20007 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752266AbcHQEbW (ORCPT ); Wed, 17 Aug 2016 00:31:22 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.28,529,1464678000"; d="scan'208";a="749751184" Date: Wed, 17 Aug 2016 07:31:13 +0300 From: Jarkko Sakkinen To: Peter Huewe Cc: linux-security-module@vger.kernel.org, stable@vger.kernel.org, Marcel Selhorst , Jason Gunthorpe , "moderated list:TPM DEVICE DRIVER" , open list Subject: Re: [PATCH] tpm: fix a race condition tpm2_unseal_trusted() Message-ID: <20160817043113.GA11281@intel.com> References: <1471376302-25365-1-git-send-email-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1471376302-25365-1-git-send-email-jarkko.sakkinen@linux.intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 16, 2016 at 10:38:22PM +0300, Jarkko Sakkinen wrote: > Unseal and load operations should be done as an atomic operation. This > commit introduces unlocked tpm_transmit() so that tpm2_unseal_trusted() > can do the locking by itself. > > v2: Introduced an unlocked unseal operation instead of changing locking > strategy in order to make less intrusive bug fix and thus more > backportable. > > CC: stable@vger.kernel.org > Fixes: 954650efb79f ("tpm: seal/unseal for TPM 2.0") > Signed-off-by: Jarkko Sakkinen > --- > drivers/char/tpm/tpm-dev.c | 2 +- > drivers/char/tpm/tpm-interface.c | 14 ++++++++------ > drivers/char/tpm/tpm.h | 18 ++++++++++++++---- > drivers/char/tpm/tpm2-cmd.c | 13 +++++++++---- > 4 files changed, 32 insertions(+), 15 deletions(-) > > diff --git a/drivers/char/tpm/tpm-dev.c b/drivers/char/tpm/tpm-dev.c > index f5d4521..8df8846 100644 > --- a/drivers/char/tpm/tpm-dev.c > +++ b/drivers/char/tpm/tpm-dev.c > @@ -145,7 +145,7 @@ static ssize_t tpm_write(struct file *file, const char __user *buf, > return -EPIPE; > } > out_size = tpm_transmit(priv->chip, priv->data_buffer, > - sizeof(priv->data_buffer)); > + sizeof(priv->data_buffer), TPM_TRANSMIT_LOCK); > > tpm_put_ops(priv->chip); > if (out_size < 0) { > diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c > index 43ef0ef..627daa7 100644 > --- a/drivers/char/tpm/tpm-interface.c > +++ b/drivers/char/tpm/tpm-interface.c > @@ -331,7 +331,7 @@ EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration); > * Internal kernel interface to transmit TPM commands > */ > ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf, > - size_t bufsiz) > + size_t bufsiz, unsigned int flags) > { > ssize_t rc; > u32 count, ordinal; > @@ -350,7 +350,8 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf, > return -E2BIG; > } > > - mutex_lock(&chip->tpm_mutex); > + if (flags & TPM_TRANSMIT_LOCK) > + mutex_lock(&chip->tpm_mutex); > > rc = chip->ops->send(chip, (u8 *) buf, count); > if (rc < 0) { > @@ -393,20 +394,21 @@ out_recv: > dev_err(&chip->dev, > "tpm_transmit: tpm_recv: error %zd\n", rc); > out: > - mutex_unlock(&chip->tpm_mutex); > + if (flags & TPM_TRANSMIT_LOCK) > + mutex_unlock(&chip->tpm_mutex); > return rc; > } > > #define TPM_DIGEST_SIZE 20 > #define TPM_RET_CODE_IDX 6 > > -ssize_t tpm_transmit_cmd(struct tpm_chip *chip, void *cmd, > - int len, const char *desc) > +ssize_t __tpm_transmit_cmd(struct tpm_chip *chip, void *cmd, > + int len, const char *desc, unsigned int flags) > { > struct tpm_output_header *header; > int err; > > - len = tpm_transmit(chip, (u8 *) cmd, len); > + len = tpm_transmit(chip, cmd, len, flags); > if (len < 0) > return len; > else if (len < TPM_HEADER_SIZE) > diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h > index 6e002c4..b9383fd 100644 > --- a/drivers/char/tpm/tpm.h > +++ b/drivers/char/tpm/tpm.h > @@ -476,12 +476,22 @@ extern dev_t tpm_devt; > extern const struct file_operations tpm_fops; > extern struct idr dev_nums_idr; > > +enum tpm_transmit_flags { > + TPM_TRANSMIT_LOCK, > +}; > + > +ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf, > + size_t bufsiz, unsigned int flags); > +ssize_t __tpm_transmit_cmd(struct tpm_chip *chip, void *cmd, int len, > + const char *desc, unsigned int flags); > +static inline ssize_t tpm_transmit_cmd(struct tpm_chip *chip, void *cmd, > + int len, const char *desc) > +{ > + return __tpm_transmit_cmd(chip, cmd, len, desc, TPM_TRANSMIT_LOCK); > +} > + > ssize_t tpm_getcap(struct tpm_chip *chip, __be32 subcap_id, cap_t *cap, > const char *desc); > -ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf, > - size_t bufsiz); By having also __tpm_transmit() the patch would be more localized, which would make it easier to backport. I think I'll add that. /Jarkko > -ssize_t tpm_transmit_cmd(struct tpm_chip *chip, void *cmd, int len, > - const char *desc); > int tpm_get_timeouts(struct tpm_chip *chip); > int tpm1_auto_startup(struct tpm_chip *chip); > int tpm_do_selftest(struct tpm_chip *chip); > diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c > index 499f405..99007d8 100644 > --- a/drivers/char/tpm/tpm2-cmd.c > +++ b/drivers/char/tpm/tpm2-cmd.c > @@ -576,7 +576,7 @@ static int tpm2_load(struct tpm_chip *chip, > goto out; > } > > - rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "loading blob"); > + rc = __tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "loading blob", 0); > if (!rc) > *blob_handle = be32_to_cpup( > (__be32 *) &buf.data[TPM_HEADER_SIZE]); > @@ -604,7 +604,8 @@ static void tpm2_flush_context(struct tpm_chip *chip, u32 handle) > > tpm_buf_append_u32(&buf, handle); > > - rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "flushing context"); > + rc = __tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "flushing context", > + 0); > if (rc) > dev_warn(&chip->dev, "0x%08x was not flushed, rc=%d\n", handle, > rc); > @@ -635,7 +636,7 @@ static int tpm2_unseal(struct tpm_chip *chip, > options->blobauth /* hmac */, > TPM_DIGEST_SIZE); > > - rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "unsealing"); > + rc = __tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "unsealing", 0); > if (rc > 0) > rc = -EPERM; > > @@ -668,13 +669,17 @@ int tpm2_unseal_trusted(struct tpm_chip *chip, > u32 blob_handle; > int rc; > > + mutex_lock(&chip->tpm_mutex); > rc = tpm2_load(chip, payload, options, &blob_handle); > - if (rc) > + if (rc) { > + mutex_unlock(&chip->tpm_mutex); > return rc; > + } > > rc = tpm2_unseal(chip, payload, options, blob_handle); > > tpm2_flush_context(chip, blob_handle); > + mutex_unlock(&chip->tpm_mutex); > > return rc; > } > -- > 2.7.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-security-module" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 17 Aug 2016 07:31:13 +0300 From: Jarkko Sakkinen To: Peter Huewe Cc: linux-security-module@vger.kernel.org, stable@vger.kernel.org, Marcel Selhorst , Jason Gunthorpe , "moderated list:TPM DEVICE DRIVER" , open list Subject: Re: [PATCH] tpm: fix a race condition tpm2_unseal_trusted() Message-ID: <20160817043113.GA11281@intel.com> References: <1471376302-25365-1-git-send-email-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1471376302-25365-1-git-send-email-jarkko.sakkinen@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: On Tue, Aug 16, 2016 at 10:38:22PM +0300, Jarkko Sakkinen wrote: > Unseal and load operations should be done as an atomic operation. This > commit introduces unlocked tpm_transmit() so that tpm2_unseal_trusted() > can do the locking by itself. > > v2: Introduced an unlocked unseal operation instead of changing locking > strategy in order to make less intrusive bug fix and thus more > backportable. > > CC: stable@vger.kernel.org > Fixes: 954650efb79f ("tpm: seal/unseal for TPM 2.0") > Signed-off-by: Jarkko Sakkinen > --- > drivers/char/tpm/tpm-dev.c | 2 +- > drivers/char/tpm/tpm-interface.c | 14 ++++++++------ > drivers/char/tpm/tpm.h | 18 ++++++++++++++---- > drivers/char/tpm/tpm2-cmd.c | 13 +++++++++---- > 4 files changed, 32 insertions(+), 15 deletions(-) > > diff --git a/drivers/char/tpm/tpm-dev.c b/drivers/char/tpm/tpm-dev.c > index f5d4521..8df8846 100644 > --- a/drivers/char/tpm/tpm-dev.c > +++ b/drivers/char/tpm/tpm-dev.c > @@ -145,7 +145,7 @@ static ssize_t tpm_write(struct file *file, const char __user *buf, > return -EPIPE; > } > out_size = tpm_transmit(priv->chip, priv->data_buffer, > - sizeof(priv->data_buffer)); > + sizeof(priv->data_buffer), TPM_TRANSMIT_LOCK); > > tpm_put_ops(priv->chip); > if (out_size < 0) { > diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c > index 43ef0ef..627daa7 100644 > --- a/drivers/char/tpm/tpm-interface.c > +++ b/drivers/char/tpm/tpm-interface.c > @@ -331,7 +331,7 @@ EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration); > * Internal kernel interface to transmit TPM commands > */ > ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf, > - size_t bufsiz) > + size_t bufsiz, unsigned int flags) > { > ssize_t rc; > u32 count, ordinal; > @@ -350,7 +350,8 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf, > return -E2BIG; > } > > - mutex_lock(&chip->tpm_mutex); > + if (flags & TPM_TRANSMIT_LOCK) > + mutex_lock(&chip->tpm_mutex); > > rc = chip->ops->send(chip, (u8 *) buf, count); > if (rc < 0) { > @@ -393,20 +394,21 @@ out_recv: > dev_err(&chip->dev, > "tpm_transmit: tpm_recv: error %zd\n", rc); > out: > - mutex_unlock(&chip->tpm_mutex); > + if (flags & TPM_TRANSMIT_LOCK) > + mutex_unlock(&chip->tpm_mutex); > return rc; > } > > #define TPM_DIGEST_SIZE 20 > #define TPM_RET_CODE_IDX 6 > > -ssize_t tpm_transmit_cmd(struct tpm_chip *chip, void *cmd, > - int len, const char *desc) > +ssize_t __tpm_transmit_cmd(struct tpm_chip *chip, void *cmd, > + int len, const char *desc, unsigned int flags) > { > struct tpm_output_header *header; > int err; > > - len = tpm_transmit(chip, (u8 *) cmd, len); > + len = tpm_transmit(chip, cmd, len, flags); > if (len < 0) > return len; > else if (len < TPM_HEADER_SIZE) > diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h > index 6e002c4..b9383fd 100644 > --- a/drivers/char/tpm/tpm.h > +++ b/drivers/char/tpm/tpm.h > @@ -476,12 +476,22 @@ extern dev_t tpm_devt; > extern const struct file_operations tpm_fops; > extern struct idr dev_nums_idr; > > +enum tpm_transmit_flags { > + TPM_TRANSMIT_LOCK, > +}; > + > +ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf, > + size_t bufsiz, unsigned int flags); > +ssize_t __tpm_transmit_cmd(struct tpm_chip *chip, void *cmd, int len, > + const char *desc, unsigned int flags); > +static inline ssize_t tpm_transmit_cmd(struct tpm_chip *chip, void *cmd, > + int len, const char *desc) > +{ > + return __tpm_transmit_cmd(chip, cmd, len, desc, TPM_TRANSMIT_LOCK); > +} > + > ssize_t tpm_getcap(struct tpm_chip *chip, __be32 subcap_id, cap_t *cap, > const char *desc); > -ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf, > - size_t bufsiz); By having also __tpm_transmit() the patch would be more localized, which would make it easier to backport. I think I'll add that. /Jarkko > -ssize_t tpm_transmit_cmd(struct tpm_chip *chip, void *cmd, int len, > - const char *desc); > int tpm_get_timeouts(struct tpm_chip *chip); > int tpm1_auto_startup(struct tpm_chip *chip); > int tpm_do_selftest(struct tpm_chip *chip); > diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c > index 499f405..99007d8 100644 > --- a/drivers/char/tpm/tpm2-cmd.c > +++ b/drivers/char/tpm/tpm2-cmd.c > @@ -576,7 +576,7 @@ static int tpm2_load(struct tpm_chip *chip, > goto out; > } > > - rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "loading blob"); > + rc = __tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "loading blob", 0); > if (!rc) > *blob_handle = be32_to_cpup( > (__be32 *) &buf.data[TPM_HEADER_SIZE]); > @@ -604,7 +604,8 @@ static void tpm2_flush_context(struct tpm_chip *chip, u32 handle) > > tpm_buf_append_u32(&buf, handle); > > - rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "flushing context"); > + rc = __tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "flushing context", > + 0); > if (rc) > dev_warn(&chip->dev, "0x%08x was not flushed, rc=%d\n", handle, > rc); > @@ -635,7 +636,7 @@ static int tpm2_unseal(struct tpm_chip *chip, > options->blobauth /* hmac */, > TPM_DIGEST_SIZE); > > - rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "unsealing"); > + rc = __tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "unsealing", 0); > if (rc > 0) > rc = -EPERM; > > @@ -668,13 +669,17 @@ int tpm2_unseal_trusted(struct tpm_chip *chip, > u32 blob_handle; > int rc; > > + mutex_lock(&chip->tpm_mutex); > rc = tpm2_load(chip, payload, options, &blob_handle); > - if (rc) > + if (rc) { > + mutex_unlock(&chip->tpm_mutex); > return rc; > + } > > rc = tpm2_unseal(chip, payload, options, blob_handle); > > tpm2_flush_context(chip, blob_handle); > + mutex_unlock(&chip->tpm_mutex); > > return rc; > } > -- > 2.7.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-security-module" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html