From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.5 required=3.0 tests=INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E0E5CC43387 for ; Thu, 20 Dec 2018 14:55:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B0CC3217D8 for ; Thu, 20 Dec 2018 14:55:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729217AbeLTOzH (ORCPT ); Thu, 20 Dec 2018 09:55:07 -0500 Received: from mga04.intel.com ([192.55.52.120]:62203 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725778AbeLTOzG (ORCPT ); Thu, 20 Dec 2018 09:55:06 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 20 Dec 2018 06:55:05 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,377,1539673200"; d="scan'208";a="285293790" Received: from unknown (HELO localhost) ([10.249.254.232]) by orsmga005.jf.intel.com with ESMTP; 20 Dec 2018 06:55:01 -0800 Date: Thu, 20 Dec 2018 16:55:00 +0200 From: Jarkko Sakkinen To: Roberto Sassu Cc: zohar@linux.ibm.com, david.safford@ge.com, monty.wiseman@ge.com, linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, silviu.vlasceanu@huawei.com Subject: Re: [PATCH v7 1/5] tpm: dynamically allocate the allocated_banks array Message-ID: <20181220145500.GA10652@linux.intel.com> References: <20181213102945.30946-1-roberto.sassu@huawei.com> <20181213102945.30946-2-roberto.sassu@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181213102945.30946-2-roberto.sassu@huawei.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.10.1 (2018-07-13) Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: On Thu, Dec 13, 2018 at 11:29:41AM +0100, Roberto Sassu wrote: > This patch renames active_banks (member of tpm_chip) to allocated_banks, > stores the number of allocated PCR banks in nr_allocated_banks (new member > of tpm_chip), and replaces the static array with a pointer to a dynamically > allocated array. > > tpm2_get_pcr_allocation() determines if a PCR bank is allocated by checking > the mask in the TPML_PCR_SELECTION structure returned by the TPM for > TPM2_Get_Capability(). If a bank is not allocated, the TPM returns that > bank in TPML_PCR_SELECTION, with all bits in the mask set to zero. In this > case, the bank is not included in chip->allocated_banks, to avoid that TPM > driver users unnecessarily calculate a digest for that bank. > > One PCR bank with algorithm set to SHA1 is always allocated for TPM 1.x. > > As a consequence of the introduction of nr_allocated_banks, > tpm_pcr_extend() does not check anymore if the algorithm stored in tpm_chip > is equal to zero. > > Signed-off-by: Roberto Sassu > Tested-by: Jarkko Sakkinen > --- > drivers/char/tpm/tpm-chip.c | 1 + > drivers/char/tpm/tpm-interface.c | 18 +++++++++-------- > drivers/char/tpm/tpm.h | 3 ++- > drivers/char/tpm/tpm1-cmd.c | 10 ++++++++++ > drivers/char/tpm/tpm2-cmd.c | 34 ++++++++++++++++++++++---------- > 5 files changed, 47 insertions(+), 19 deletions(-) > > diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c > index 32db84683c40..ce851c62bb68 100644 > --- a/drivers/char/tpm/tpm-chip.c > +++ b/drivers/char/tpm/tpm-chip.c > @@ -160,6 +160,7 @@ static void tpm_dev_release(struct device *dev) > kfree(chip->log.bios_event_log); > kfree(chip->work_space.context_buf); > kfree(chip->work_space.session_buf); > + kfree(chip->allocated_banks); > kfree(chip); > } > > diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c > index d9439f9abe78..7b80919228be 100644 > --- a/drivers/char/tpm/tpm-interface.c > +++ b/drivers/char/tpm/tpm-interface.c > @@ -488,8 +488,7 @@ EXPORT_SYMBOL_GPL(tpm_pcr_read); > int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8 *hash) > { > int rc; > - struct tpm2_digest digest_list[ARRAY_SIZE(chip->active_banks)]; > - u32 count = 0; > + struct tpm2_digest *digest_list; > int i; > > chip = tpm_find_get_ops(chip); > @@ -497,16 +496,19 @@ int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8 *hash) > return -ENODEV; > > if (chip->flags & TPM_CHIP_FLAG_TPM2) { > - memset(digest_list, 0, sizeof(digest_list)); > + digest_list = kcalloc(chip->nr_allocated_banks, > + sizeof(*digest_list), GFP_KERNEL); > + if (!digest_list) > + return -ENOMEM; You could preallocate digest list and place it to struct tpm_chip instead of doing it everytime tpm_pcr_extend() called. > > - for (i = 0; i < ARRAY_SIZE(chip->active_banks) && > - chip->active_banks[i] != TPM2_ALG_ERROR; i++) { > - digest_list[i].alg_id = chip->active_banks[i]; > + for (i = 0; i < chip->nr_allocated_banks; i++) { > + digest_list[i].alg_id = chip->allocated_banks[i]; > memcpy(digest_list[i].digest, hash, TPM_DIGEST_SIZE); > - count++; > } > > - rc = tpm2_pcr_extend(chip, pcr_idx, count, digest_list); > + rc = tpm2_pcr_extend(chip, pcr_idx, chip->nr_allocated_banks, > + digest_list); > + kfree(digest_list); > tpm_put_ops(chip); > return rc; > } > diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h > index f27d1f38a93d..6b94306ab7c5 100644 > --- a/drivers/char/tpm/tpm.h > +++ b/drivers/char/tpm/tpm.h > @@ -257,7 +257,8 @@ struct tpm_chip { > const struct attribute_group *groups[3]; > unsigned int groups_cnt; > > - u16 active_banks[7]; > + u32 nr_allocated_banks; > + u16 *allocated_banks; > #ifdef CONFIG_ACPI > acpi_handle acpi_dev_handle; > char ppi_version[TPM_PPI_VERSION_LEN + 1]; > diff --git a/drivers/char/tpm/tpm1-cmd.c b/drivers/char/tpm/tpm1-cmd.c > index 6f306338953b..0874743ca96d 100644 > --- a/drivers/char/tpm/tpm1-cmd.c > +++ b/drivers/char/tpm/tpm1-cmd.c > @@ -709,6 +709,16 @@ int tpm1_auto_startup(struct tpm_chip *chip) > goto out; > } > > + chip->allocated_banks = kcalloc(1, sizeof(*chip->allocated_banks), > + GFP_KERNEL); > + if (!chip->allocated_banks) { > + rc = -ENOMEM; > + goto out; > + } > + > + chip->allocated_banks[0] = TPM2_ALG_SHA1; > + chip->nr_allocated_banks = 1; > + > return rc; > out: > if (rc > 0) > diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c > index a6bec13afa69..245669a7aba5 100644 > --- a/drivers/char/tpm/tpm2-cmd.c > +++ b/drivers/char/tpm/tpm2-cmd.c > @@ -234,7 +234,7 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, u32 count, > int i; > int j; > > - if (count > ARRAY_SIZE(chip->active_banks)) > + if (count > chip->nr_allocated_banks) > return -EINVAL; > > rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_PCR_EXTEND); > @@ -825,11 +825,14 @@ static ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip) > void *marker; > void *end; > void *pcr_select_offset; > - unsigned int count; > u32 sizeof_pcr_selection; > + u32 nr_possible_banks; > + u32 nr_alloc_banks = 0; > + u16 hash_alg; > u32 rsp_len; > int rc; > int i = 0; > + int j; > > rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY); > if (rc) > @@ -844,11 +847,14 @@ static ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip) > if (rc) > goto out; > > - count = be32_to_cpup( > + nr_possible_banks = be32_to_cpup( > (__be32 *)&buf.data[TPM_HEADER_SIZE + 5]); > > - if (count > ARRAY_SIZE(chip->active_banks)) { > - rc = -ENODEV; > + chip->allocated_banks = kcalloc(nr_possible_banks, > + sizeof(*chip->allocated_banks), > + GFP_KERNEL); > + if (!chip->allocated_banks) { > + rc = -ENOMEM; > goto out; > } > > @@ -857,7 +863,7 @@ static ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip) > rsp_len = be32_to_cpup((__be32 *)&buf.data[2]); > end = &buf.data[rsp_len]; > > - for (i = 0; i < count; i++) { > + for (i = 0; i < nr_possible_banks; i++) { > pcr_select_offset = marker + > offsetof(struct tpm2_pcr_selection, size_of_select); > if (pcr_select_offset >= end) { > @@ -866,17 +872,25 @@ static ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip) > } > > memcpy(&pcr_selection, marker, sizeof(pcr_selection)); > - chip->active_banks[i] = be16_to_cpu(pcr_selection.hash_alg); > + hash_alg = be16_to_cpu(pcr_selection.hash_alg); > + > + for (j = 0; j < pcr_selection.size_of_select; j++) > + if (pcr_selection.pcr_select[j]) > + break; > + > + if (j < pcr_selection.size_of_select) { > + chip->allocated_banks[nr_alloc_banks] = hash_alg; > + nr_alloc_banks++; > + } The same comment as before: you should use memchr_inv() here. > + > sizeof_pcr_selection = sizeof(pcr_selection.hash_alg) + > sizeof(pcr_selection.size_of_select) + > pcr_selection.size_of_select; > marker = marker + sizeof_pcr_selection; > } > > + chip->nr_allocated_banks = nr_alloc_banks; > out: > - if (i < ARRAY_SIZE(chip->active_banks)) > - chip->active_banks[i] = TPM2_ALG_ERROR; > - > tpm_buf_destroy(&buf); > > return rc; > -- > 2.17.1 > /Jarkko