From patchwork Tue Sep 29 22:51:41 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 11807339 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8AD6C139A for ; Tue, 29 Sep 2020 22:51:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 75564207C4 for ; Tue, 29 Sep 2020 22:51:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728511AbgI2Wvu (ORCPT ); Tue, 29 Sep 2020 18:51:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:49536 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728115AbgI2Wvt (ORCPT ); Tue, 29 Sep 2020 18:51:49 -0400 Received: from localhost (83-245-197-237.elisa-laajakaista.fi [83.245.197.237]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4539620757; Tue, 29 Sep 2020 22:51:48 +0000 (UTC) From: Jarkko Sakkinen To: linux-integrity@vger.kernel.org Cc: Jarkko Sakkinen , "James E.J. Bottomley" , Sumit Garg , David Howells , stable@vger.kernel.org Subject: [PATCH v3 2/2] KEYS: trusted: Reserve TPM for seal and unseal operations Date: Wed, 30 Sep 2020 01:51:41 +0300 Message-Id: <20200929225141.804688-2-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200929225141.804688-1-jarkko.sakkinen@linux.intel.com> References: <20200929225141.804688-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org When TPM 2.0 trusted keys code was moved to the trusted keys subsystem, the operations were unwrapped from tpm_try_get_ops() and tpm_put_ops(), which are used to take temporarily the ownership of the TPM chip. The ownership is only taken inside tpm_send(), but this is not sufficient, as in the key load TPM2_CC_LOAD, TPM2_CC_UNSEAL and TPM2_FLUSH_CONTEXT need to be done as a one single atom. Fix this issue by introducting trusted_tpm_load() and trusted_tpm_new(), which wrap these operations, and take the TPM chip ownership before sending anything. Use tpm_transmit_cmd() to send TPM commands instead of tpm_send(), reverting back to the old behaviour. Fixes: 2e19e10131a0 ("KEYS: trusted: Move TPM2 trusted keys code") Reported-by: "James E.J. Bottomley" Cc: Sumit Garg Cc: David Howells Cc: stable@vger.kernel.org Signed-off-by: Jarkko Sakkinen --- drivers/char/tpm/tpm.h | 4 -- include/linux/tpm.h | 16 ++++- security/keys/trusted-keys/trusted_tpm1.c | 78 +++++++++++++++-------- security/keys/trusted-keys/trusted_tpm2.c | 6 +- 4 files changed, 71 insertions(+), 33 deletions(-) diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 947d1db0a5cc..283f78211c3a 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -164,8 +164,6 @@ extern const struct file_operations tpmrm_fops; extern struct idr dev_nums_idr; ssize_t tpm_transmit(struct tpm_chip *chip, u8 *buf, size_t bufsiz); -ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_buf *buf, - size_t min_rsp_body_length, const char *desc); int tpm_get_timeouts(struct tpm_chip *); int tpm_auto_startup(struct tpm_chip *chip); @@ -194,8 +192,6 @@ static inline void tpm_msleep(unsigned int delay_msec) int tpm_chip_start(struct tpm_chip *chip); void tpm_chip_stop(struct tpm_chip *chip); struct tpm_chip *tpm_find_get_ops(struct tpm_chip *chip); -__must_check int tpm_try_get_ops(struct tpm_chip *chip); -void tpm_put_ops(struct tpm_chip *chip); struct tpm_chip *tpm_chip_alloc(struct device *dev, const struct tpm_class_ops *ops); diff --git a/include/linux/tpm.h b/include/linux/tpm.h index 8f4ff39f51e7..c908349a2f15 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -397,6 +397,10 @@ static inline u32 tpm2_rc_value(u32 rc) #if defined(CONFIG_TCG_TPM) || defined(CONFIG_TCG_TPM_MODULE) extern int tpm_is_tpm2(struct tpm_chip *chip); +extern __must_check int tpm_try_get_ops(struct tpm_chip *chip); +extern void tpm_put_ops(struct tpm_chip *chip); +extern ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_buf *buf, + size_t min_rsp_body_length, const char *desc); extern int tpm_pcr_read(struct tpm_chip *chip, u32 pcr_idx, struct tpm_digest *digest); extern int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, @@ -410,7 +414,17 @@ static inline int tpm_is_tpm2(struct tpm_chip *chip) { return -ENODEV; } - +static inline int tpm_try_get_ops(struct tpm_chip *chip) +{ + return -ENODEV; +} +static inline void tpm_put_ops(struct tpm_chip *chip) +{ +} +extern ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_buf *buf, + size_t min_rsp_body_length, const char *desc) +{ +} static inline int tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, struct tpm_digest *digest) { diff --git a/security/keys/trusted-keys/trusted_tpm1.c b/security/keys/trusted-keys/trusted_tpm1.c index c7b1701cdac5..c1dfc32c780b 100644 --- a/security/keys/trusted-keys/trusted_tpm1.c +++ b/security/keys/trusted-keys/trusted_tpm1.c @@ -950,6 +950,51 @@ static struct trusted_key_payload *trusted_payload_alloc(struct key *key) return p; } +static int trusted_tpm_load(struct tpm_chip *chip, + struct trusted_key_payload *payload, + struct trusted_key_options *options) +{ + int ret; + + if (tpm_is_tpm2(chip)) { + ret = tpm_try_get_ops(chip); + if (!ret) { + ret = tpm2_unseal_trusted(chip, payload, options); + tpm_put_ops(chip); + } + } else { + ret = key_unseal(payload, options); + } + + return ret; +} + +static int trusted_tpm_new(struct tpm_chip *chip, + struct trusted_key_payload *payload, + struct trusted_key_options *options) +{ + int ret; + + ret = tpm_get_random(chip, payload->key, payload->key_len); + if (ret < 0) + return ret; + + if (ret != payload->key_len) + return -EIO; + + if (tpm_is_tpm2(chip)) { + ret = tpm_try_get_ops(chip); + if (!ret) { + ret = tpm2_seal_trusted(chip, payload, options); + tpm_put_ops(chip); + } + } else { + ret = key_seal(payload, options); + } + + return ret; +} + /* * trusted_instantiate - create a new trusted key * @@ -968,12 +1013,6 @@ static int trusted_instantiate(struct key *key, char *datablob; int ret = 0; int key_cmd; - size_t key_len; - int tpm2; - - tpm2 = tpm_is_tpm2(chip); - if (tpm2 < 0) - return tpm2; if (datalen <= 0 || datalen > 32767 || !prep->data) return -EINVAL; @@ -1011,32 +1050,21 @@ static int trusted_instantiate(struct key *key, switch (key_cmd) { case Opt_load: - if (tpm2) - ret = tpm2_unseal_trusted(chip, payload, options); - else - ret = key_unseal(payload, options); + ret = trusted_tpm_load(chip, payload, options); + dump_payload(payload); dump_options(options); + if (ret < 0) - pr_info("trusted_key: key_unseal failed (%d)\n", ret); + pr_info("%s: load failed (%d)\n", __func__, ret); + break; case Opt_new: - key_len = payload->key_len; - ret = tpm_get_random(chip, payload->key, key_len); - if (ret < 0) - goto out; + ret = trusted_tpm_new(chip, payload, options); - if (ret != key_len) { - pr_info("trusted_key: key_create failed (%d)\n", ret); - ret = -EIO; - goto out; - } - if (tpm2) - ret = tpm2_seal_trusted(chip, payload, options); - else - ret = key_seal(payload, options); if (ret < 0) - pr_info("trusted_key: key_seal failed (%d)\n", ret); + pr_info("%s: new failed (%d)\n", __func__, ret); + break; default: ret = -EINVAL; diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c index 08ec7f48f01d..effdb67fac6d 100644 --- a/security/keys/trusted-keys/trusted_tpm2.c +++ b/security/keys/trusted-keys/trusted_tpm2.c @@ -130,7 +130,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip, goto out; } - rc = tpm_send(chip, buf.data, tpm_buf_length(&buf)); + rc = tpm_transmit_cmd(chip, &buf, 4, "sealing data"); if (rc) goto out; @@ -211,7 +211,7 @@ static int tpm2_load_cmd(struct tpm_chip *chip, goto out; } - rc = tpm_send(chip, buf.data, tpm_buf_length(&buf)); + rc = tpm_transmit_cmd(chip, &buf, 4, "loading blob"); if (!rc) *blob_handle = be32_to_cpup( (__be32 *) &buf.data[TPM_HEADER_SIZE]); @@ -260,7 +260,7 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip, options->blobauth /* hmac */, TPM_DIGEST_SIZE); - rc = tpm_send(chip, buf.data, tpm_buf_length(&buf)); + rc = tpm_transmit_cmd(chip, &buf, 6, "unsealing"); if (rc > 0) rc = -EPERM;