From patchwork Thu Jan 12 17:46:04 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 9513745 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 7BA6760762 for ; Thu, 12 Jan 2017 17:49:22 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 71D1D286F3 for ; Thu, 12 Jan 2017 17:49:22 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 669C7286FA; Thu, 12 Jan 2017 17:49:22 +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=unavailable 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 BD5B2286F3 for ; Thu, 12 Jan 2017 17:49:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751439AbdALRsO (ORCPT ); Thu, 12 Jan 2017 12:48:14 -0500 Received: from mga03.intel.com ([134.134.136.65]:25132 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751096AbdALRqW (ORCPT ); Thu, 12 Jan 2017 12:46:22 -0500 Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga103.jf.intel.com with ESMTP; 12 Jan 2017 09:46:21 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.33,219,1477983600"; d="scan'208";a="48211556" Received: from gregoryh-mobl.ger.corp.intel.com (HELO localhost) ([10.252.58.8]) by orsmga004.jf.intel.com with ESMTP; 12 Jan 2017 09:46:18 -0800 From: Jarkko Sakkinen To: tpmdd-devel@lists.sourceforge.net Cc: linux-security-module@vger.kernel.org, Jarkko Sakkinen , Peter Huewe , Marcel Selhorst , Jason Gunthorpe , linux-kernel@vger.kernel.org (open list) Subject: [PATCH RFC v2 1/5] tpm: validate TPM 2.0 commands Date: Thu, 12 Jan 2017 19:46:04 +0200 Message-Id: <20170112174612.9314-2-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20170112174612.9314-1-jarkko.sakkinen@linux.intel.com> References: <20170112174612.9314-1-jarkko.sakkinen@linux.intel.com> Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP Check for every TPM 2.0 command that the command code is supported and the command buffer has at least the length that can contain the header and the handle area. Signed-off-by: Jarkko Sakkinen --- drivers/char/tpm/tpm-interface.c | 32 ++++++++++++++++++++++++- drivers/char/tpm/tpm.h | 27 +++++++++++++++++---- drivers/char/tpm/tpm2-cmd.c | 51 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 105 insertions(+), 5 deletions(-) diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index fecdd3f..0c5aba1 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -328,6 +328,36 @@ unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip, } EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration); +static bool tpm_validate_command(struct tpm_chip *chip, const u8 *cmd, + size_t len) +{ + const struct tpm_input_header *header = (const void *)cmd; + u32 cc; + size_t len_min = TPM_HEADER_SIZE; + u32 attrs; + + if ((len >= len_min) && (chip->flags & TPM_CHIP_FLAG_TPM2) && + chip->nr_commands) { + cc = be32_to_cpu(header->ordinal); + if (!tpm2_find_cc_attrs(chip, cc, &attrs)) { + dev_dbg(&chip->dev, "0x%04x is an invalid command\n", + cc); + return false; + } + len_min += + 4 * ((attrs >> TPM2_CC_ATTR_CHANDLES) & GENMASK(2, 0)); + } + + if (len < len_min) { + dev_dbg(&chip->dev, + "%s: insufficient command length %zu < %zu\n", + __func__, len, len_min); + return false; + } + + return true; +} + /** * tmp_transmit - Internal kernel interface to transmit TPM commands. * @@ -347,7 +377,7 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz, u32 count, ordinal; unsigned long stop; - if (bufsiz < TPM_HEADER_SIZE) + if (!tpm_validate_command(chip, buf, bufsiz)) return -EINVAL; if (bufsiz > TPM_BUFSIZE) diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 1ae9768..80fa606 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -127,7 +127,12 @@ enum tpm2_permanent_handles { }; enum tpm2_capabilities { - TPM2_CAP_TPM_PROPERTIES = 6, + TPM2_CAP_COMMANDS = 2, + TPM2_CAP_TPM_PROPERTIES = 6, +}; + +enum tpm2_properties { + TPM_PT_TOTAL_COMMANDS = 0x0129, }; enum tpm2_startup_types { @@ -135,6 +140,11 @@ enum tpm2_startup_types { TPM2_SU_STATE = 0x0001, }; +enum tpm2_cc_attrs { + TPM2_CC_ATTR_CHANDLES = 25, + TPM2_CC_ATTR_RHANDLE = 28, +}; + #define TPM_VID_INTEL 0x8086 #define TPM_VID_WINBOND 0x1050 #define TPM_VID_STM 0x104A @@ -191,6 +201,9 @@ struct tpm_chip { acpi_handle acpi_dev_handle; char ppi_version[TPM_PPI_VERSION_LEN + 1]; #endif /* CONFIG_ACPI */ + + u32 nr_commands; + u32 *cc_attrs_tbl; }; #define to_tpm_chip(d) container_of(d, struct tpm_chip, dev) @@ -393,7 +406,8 @@ struct tpm_cmd_t { */ enum tpm_buf_flags { - TPM_BUF_OVERFLOW = BIT(0), + TPM_BUF_INITIALIZED = BIT(0), + TPM_BUF_OVERFLOW = BIT(1), }; struct tpm_buf { @@ -419,13 +433,17 @@ static inline int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal) head->length = cpu_to_be32(sizeof(*head)); head->ordinal = cpu_to_be32(ordinal); + buf->flags = TPM_BUF_INITIALIZED; + return 0; } static inline void tpm_buf_destroy(struct tpm_buf *buf) { - kunmap(buf->data_page); - __free_page(buf->data_page); + if (buf->flags & TPM_BUF_INITIALIZED) { + kunmap(buf->data_page); + __free_page(buf->data_page); + } } static inline u32 tpm_buf_length(struct tpm_buf *buf) @@ -545,4 +563,5 @@ 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); +bool tpm2_find_cc_attrs(struct tpm_chip *chip, u32 cc, u32 *attrs); #endif diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index 6eda239..c4d25b2 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -969,7 +969,10 @@ EXPORT_SYMBOL_GPL(tpm2_probe); */ int tpm2_auto_startup(struct tpm_chip *chip) { + struct tpm_buf buf; + u32 nr_commands; int rc; + int i; rc = tpm_get_timeouts(chip); if (rc) @@ -993,8 +996,56 @@ int tpm2_auto_startup(struct tpm_chip *chip) } } + rc = tpm2_get_tpm_pt(chip, TPM_PT_TOTAL_COMMANDS, &nr_commands, NULL); + if (rc) + goto out; + + chip->cc_attrs_tbl = devm_kzalloc(&chip->dev, 4 * nr_commands, + GFP_KERNEL); + + rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY); + if (rc) + goto out; + + tpm_buf_append_u32(&buf, TPM2_CAP_COMMANDS); + tpm_buf_append_u32(&buf, TPM2_CC_FIRST); + tpm_buf_append_u32(&buf, nr_commands); + + rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, 0, NULL); + if (rc < 0) { + tpm_buf_destroy(&buf); + goto out; + } + + if (nr_commands != + be32_to_cpup((__be32 *)&buf.data[TPM_HEADER_SIZE + 5])) { + tpm_buf_destroy(&buf); + goto out; + } + + for (i = 0; i < nr_commands; i++) + chip->cc_attrs_tbl[i] = be32_to_cpup( + (u32 *)&buf.data[TPM_HEADER_SIZE + 9 + 4 * i]); + + chip->nr_commands = nr_commands; + tpm_buf_destroy(&buf); + out: if (rc > 0) rc = -ENODEV; return rc; } + +bool tpm2_find_cc_attrs(struct tpm_chip *chip, u32 cc, u32 *attrs) +{ + int i; + + for (i = 0; i < chip->nr_commands; i++) { + if (cc == (chip->cc_attrs_tbl[i] & GENMASK(15, 0))) { + *attrs = chip->cc_attrs_tbl[i]; + return true; + } + } + + return false; +}