From patchwork Mon Jan 16 13:12:07 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 9518705 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 927B9600C5 for ; Mon, 16 Jan 2017 13:13:23 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 789BD28447 for ; Mon, 16 Jan 2017 13:13:23 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6D9202846C; Mon, 16 Jan 2017 13:13:23 +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 D491928447 for ; Mon, 16 Jan 2017 13:13:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751485AbdAPNM5 (ORCPT ); Mon, 16 Jan 2017 08:12:57 -0500 Received: from mga03.intel.com ([134.134.136.65]:50299 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751467AbdAPNMs (ORCPT ); Mon, 16 Jan 2017 08:12:48 -0500 Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga103.jf.intel.com with ESMTP; 16 Jan 2017 05:12:25 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.33,239,1477983600"; d="scan'208";a="53576483" Received: from jsakkine-mobl1.tm.intel.com (HELO localhost) ([10.237.50.85]) by orsmga005.jf.intel.com with ESMTP; 16 Jan 2017 05:12:21 -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 v3 1/5] tpm: validate TPM 2.0 commands Date: Mon, 16 Jan 2017 15:12:07 +0200 Message-Id: <20170116131215.28930-2-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20170116131215.28930-1-jarkko.sakkinen@linux.intel.com> References: <20170116131215.28930-1-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 403d332..fe863f2 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 9e81865..52d805f 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) @@ -546,4 +564,5 @@ 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 201538e..3dce7b7 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -1005,7 +1005,10 @@ 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) @@ -1029,8 +1032,56 @@ 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; +}