From patchwork Sun Aug 28 06:36:52 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 9302551 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 2B50F6077C for ; Sun, 28 Aug 2016 06:37:06 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0CC6928960 for ; Sun, 28 Aug 2016 06:37:06 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F34502898B; Sun, 28 Aug 2016 06:37:05 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BC47928960 for ; Sun, 28 Aug 2016 06:37:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932233AbcH1GhD (ORCPT ); Sun, 28 Aug 2016 02:37:03 -0400 Received: from mga03.intel.com ([134.134.136.65]:20976 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932187AbcH1GhC (ORCPT ); Sun, 28 Aug 2016 02:37:02 -0400 Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga103.jf.intel.com with ESMTP; 27 Aug 2016 23:37:00 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.28,590,1464678000"; d="scan'208";a="1974722" Received: from dsilcox1-mobl1.amr.corp.intel.com (HELO localhost) ([10.252.11.35]) by orsmga004.jf.intel.com with ESMTP; 27 Aug 2016 23:36:57 -0700 From: Jarkko Sakkinen To: Peter Huewe Cc: linux-security-module@vger.kernel.org, Jarkko Sakkinen , stable@vger.kernel.org, Marcel Selhorst , Jason Gunthorpe , tpmdd-devel@lists.sourceforge.net (moderated list:TPM DEVICE DRIVER), linux-kernel@vger.kernel.org (open list) Subject: [PATCH] tpm: fix a race condition in tpm2_unseal_trusted() Date: Sun, 28 Aug 2016 08:36:52 +0200 Message-Id: <1472366212-8571-1-git-send-email-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.7.4 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP 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. v3: Have also separate __tpm_transmit() that takes 'flags' in order to better localize the bug fix and make it easier to backport. v4: Cleaned up the control flow in tpm2_unseal_trusted. Added the missing 'Fixes' line. v5: Previous versions did not set the enum to any value, so it was set to zero. Changed enum to TPM_TRANSMIT_UNLOCKED because it is guaranteed to catch such situation. With change the common case adds so little clutter that the wrappers do not make sense anymore. Fixes: 0fe5480303a1 ("keys, trusted: seal/unseal with TPM 2.0 chips") CC: stable@vger.kernel.org Signed-off-by: Jarkko Sakkinen --- drivers/char/tpm/tpm-dev.c | 2 +- drivers/char/tpm/tpm-interface.c | 51 ++++++++++++++++++++++------------------ drivers/char/tpm/tpm-sysfs.c | 2 +- drivers/char/tpm/tpm.h | 12 ++++++---- drivers/char/tpm/tpm2-cmd.c | 34 ++++++++++++++++----------- 5 files changed, 58 insertions(+), 43 deletions(-) diff --git a/drivers/char/tpm/tpm-dev.c b/drivers/char/tpm/tpm-dev.c index f5d4521..912ad30 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), 0); 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 1abe2d7..aef20ee 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -330,8 +330,8 @@ 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) +ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, 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_UNLOCKED)) + 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_UNLOCKED)) + 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, const void *cmd, + int len, unsigned int flags, const char *desc) { - struct tpm_output_header *header; + const struct tpm_output_header *header; int err; - len = tpm_transmit(chip, (u8 *) cmd, len); + len = tpm_transmit(chip, (const u8 *)cmd, len, flags); if (len < 0) return len; else if (len < TPM_HEADER_SIZE) @@ -453,7 +455,8 @@ ssize_t tpm_getcap(struct tpm_chip *chip, __be32 subcap_id, cap_t *cap, tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4); tpm_cmd.params.getcap_in.subcap = subcap_id; } - rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, desc); + rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0, + desc); if (!rc) *cap = tpm_cmd.params.getcap_out.cap; return rc; @@ -469,7 +472,7 @@ void tpm_gen_interrupt(struct tpm_chip *chip) tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4); tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT; - rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, + rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0, "attempting to determine the timeouts"); } EXPORT_SYMBOL_GPL(tpm_gen_interrupt); @@ -490,7 +493,7 @@ static int tpm_startup(struct tpm_chip *chip, __be16 startup_type) start_cmd.header.in = tpm_startup_header; start_cmd.params.startup_in.startup_type = startup_type; - return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE, + return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE, 0, "attempting to start the TPM"); } @@ -521,7 +524,8 @@ int tpm_get_timeouts(struct tpm_chip *chip) tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP; tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4); tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT; - rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, NULL); + rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0, + NULL); if (rc == TPM_ERR_INVALID_POSTINIT) { /* The TPM is not started, we are the first to talk to it. @@ -535,7 +539,7 @@ int tpm_get_timeouts(struct tpm_chip *chip) tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4); tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT; rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, - NULL); + 0, NULL); } if (rc) { dev_err(&chip->dev, @@ -596,7 +600,7 @@ duration: tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4); tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION; - rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, + rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0, "attempting to determine the durations"); if (rc) return rc; @@ -652,7 +656,7 @@ static int tpm_continue_selftest(struct tpm_chip *chip) struct tpm_cmd_t cmd; cmd.header.in = continue_selftest_header; - rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE, + rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE, 0, "continue selftest"); return rc; } @@ -672,7 +676,7 @@ int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf) cmd.header.in = pcrread_header; cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx); - rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE, + rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE, 0, "attempting to read a pcr value"); if (rc == 0) @@ -770,7 +774,7 @@ int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash) cmd.header.in = pcrextend_header; cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx); memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE); - rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, + rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0, "attempting extend a PCR value"); tpm_put_ops(chip); @@ -809,7 +813,7 @@ int tpm_do_selftest(struct tpm_chip *chip) /* Attempt to read a PCR value */ cmd.header.in = pcrread_header; cmd.params.pcrread_in.pcr_idx = cpu_to_be32(0); - rc = tpm_transmit(chip, (u8 *) &cmd, READ_PCR_RESULT_SIZE); + rc = tpm_transmit(chip, (u8 *) &cmd, READ_PCR_RESULT_SIZE, 0); /* Some buggy TPMs will not respond to tpm_tis_ready() for * around 300ms while the self test is ongoing, keep trying * until the self test duration expires. */ @@ -879,7 +883,7 @@ int tpm_send(u32 chip_num, void *cmd, size_t buflen) if (chip == NULL) return -ENODEV; - rc = tpm_transmit_cmd(chip, cmd, buflen, "attempting tpm_cmd"); + rc = tpm_transmit_cmd(chip, cmd, buflen, 0, "attempting tpm_cmd"); tpm_put_ops(chip); return rc; @@ -981,14 +985,15 @@ int tpm_pm_suspend(struct device *dev) cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr); memcpy(cmd.params.pcrextend_in.hash, dummy_hash, TPM_DIGEST_SIZE); - rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, + rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0, "extending dummy pcr before suspend"); } /* now do the actual savestate */ for (try = 0; try < TPM_RETRY; try++) { cmd.header.in = savestate_header; - rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, NULL); + rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, 0, + NULL); /* * If the TPM indicates that it is too busy to respond to @@ -1072,8 +1077,8 @@ int tpm_get_random(u32 chip_num, u8 *out, size_t max) tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes); err = tpm_transmit_cmd(chip, &tpm_cmd, - TPM_GETRANDOM_RESULT_SIZE + num_bytes, - "attempting get random"); + TPM_GETRANDOM_RESULT_SIZE + num_bytes, + 0, "attempting get random"); if (err) break; diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c index b46cf70..e1f7236 100644 --- a/drivers/char/tpm/tpm-sysfs.c +++ b/drivers/char/tpm/tpm-sysfs.c @@ -39,7 +39,7 @@ static ssize_t pubek_show(struct device *dev, struct device_attribute *attr, struct tpm_chip *chip = to_tpm_chip(dev); tpm_cmd.header.in = tpm_readpubek_header; - err = tpm_transmit_cmd(chip, &tpm_cmd, READ_PUBEK_RESULT_SIZE, + err = tpm_transmit_cmd(chip, &tpm_cmd, READ_PUBEK_RESULT_SIZE, 0, "attempting to read the PUBEK"); if (err) goto out; diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 3e32d5b..b0585e9 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -476,12 +476,16 @@ extern dev_t tpm_devt; extern const struct file_operations tpm_fops; extern struct idr dev_nums_idr; +enum tpm_transmit_flags { + TPM_TRANSMIT_UNLOCKED = BIT(0), +}; + +ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz, + unsigned int flags); +ssize_t tpm_transmit_cmd(struct tpm_chip *chip, const void *cmd, int len, + unsigned int flags, const char *desc); 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); -ssize_t tpm_transmit_cmd(struct tpm_chip *chip, void *cmd, int len, - const char *desc); extern int tpm_get_timeouts(struct tpm_chip *); extern void tpm_gen_interrupt(struct tpm_chip *); int tpm1_auto_startup(struct tpm_chip *chip); diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index 08c7e23..5452ba7 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -282,7 +282,7 @@ int tpm2_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf) sizeof(cmd.params.pcrread_in.pcr_select)); cmd.params.pcrread_in.pcr_select[pcr_idx >> 3] = 1 << (pcr_idx & 0x7); - rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), + rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, "attempting to read a pcr value"); if (rc == 0) { buf = cmd.params.pcrread_out.digest; @@ -330,7 +330,7 @@ int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash) cmd.params.pcrextend_in.hash_alg = cpu_to_be16(TPM2_ALG_SHA1); memcpy(cmd.params.pcrextend_in.digest, hash, TPM_DIGEST_SIZE); - rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), + rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, "attempting extend a PCR value"); return rc; @@ -376,7 +376,7 @@ int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t max) cmd.header.in = tpm2_getrandom_header; cmd.params.getrandom_in.size = cpu_to_be16(num_bytes); - err = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), + err = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, "attempting get random"); if (err) break; @@ -512,7 +512,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip, goto out; } - rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "sealing data"); + rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, 0, "sealing data"); if (rc) goto out; @@ -576,7 +576,8 @@ 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, TPM_TRANSMIT_UNLOCKED, + "loading blob"); if (!rc) *blob_handle = be32_to_cpup( (__be32 *) &buf.data[TPM_HEADER_SIZE]); @@ -604,7 +605,8 @@ 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, TPM_TRANSMIT_UNLOCKED, + "flushing context"); if (rc) dev_warn(&chip->dev, "0x%08x was not flushed, rc=%d\n", handle, rc); @@ -635,7 +637,8 @@ 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, TPM_TRANSMIT_UNLOCKED, + "unsealing"); if (rc > 0) rc = -EPERM; @@ -668,14 +671,17 @@ 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) - return rc; + goto out; rc = tpm2_unseal(chip, payload, options, blob_handle); tpm2_flush_context(chip, blob_handle); +out: + mutex_unlock(&chip->tpm_mutex); return rc; } @@ -701,7 +707,7 @@ ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id, u32 *value, cmd.params.get_tpm_pt_in.property_id = cpu_to_be32(property_id); cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1); - rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), desc); + rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, desc); if (!rc) *value = be32_to_cpu(cmd.params.get_tpm_pt_out.value); @@ -735,7 +741,7 @@ static int tpm2_startup(struct tpm_chip *chip, u16 startup_type) cmd.header.in = tpm2_startup_header; cmd.params.startup_in.startup_type = cpu_to_be16(startup_type); - return tpm_transmit_cmd(chip, &cmd, sizeof(cmd), + return tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, "attempting to start the TPM"); } @@ -763,7 +769,7 @@ void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type) cmd.header.in = tpm2_shutdown_header; cmd.params.startup_in.startup_type = cpu_to_be16(shutdown_type); - rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), "stopping the TPM"); + rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, "stopping the TPM"); /* In places where shutdown command is sent there's no much we can do * except print the error code on a system failure. @@ -828,7 +834,7 @@ static int tpm2_start_selftest(struct tpm_chip *chip, bool full) cmd.header.in = tpm2_selftest_header; cmd.params.selftest_in.full_test = full; - rc = tpm_transmit_cmd(chip, &cmd, TPM2_SELF_TEST_IN_SIZE, + rc = tpm_transmit_cmd(chip, &cmd, TPM2_SELF_TEST_IN_SIZE, 0, "continue selftest"); /* At least some prototype chips seem to give RC_TESTING error @@ -880,7 +886,7 @@ static int tpm2_do_selftest(struct tpm_chip *chip) cmd.params.pcrread_in.pcr_select[1] = 0x00; cmd.params.pcrread_in.pcr_select[2] = 0x00; - rc = tpm_transmit_cmd(chip, (u8 *) &cmd, sizeof(cmd), NULL); + rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, NULL); if (rc < 0) break; @@ -928,7 +934,7 @@ int tpm2_probe(struct tpm_chip *chip) cmd.params.get_tpm_pt_in.property_id = cpu_to_be32(0x100); cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1); - rc = tpm_transmit(chip, (const char *) &cmd, sizeof(cmd)); + rc = tpm_transmit(chip, (const u8 *)&cmd, sizeof(cmd), 0); if (rc < 0) return rc; else if (rc < TPM_HEADER_SIZE)