From bcfff8384f6c4e6627676ef07ccad9cfacd67849 Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Wed, 6 Feb 2019 17:24:47 +0100 Subject: tpm: dynamically allocate the allocated_banks array 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 Reviewed-by: Jarkko Sakkinen Signed-off-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 | 31 +++++++++++++++++++++---------- 5 files changed, 44 insertions(+), 19 deletions(-) diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index 4eb48cf6a03a..8804c9e916fd 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -266,6 +266,7 @@ 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 498809bf1bf0..2b31eff06b0e 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -318,8 +318,7 @@ 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); @@ -327,16 +326,19 @@ 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; - 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 183e2b93e0fe..cd330ace6248 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 ec5f3693c096..e7d3228a0f37 100644 --- a/drivers/char/tpm/tpm1-cmd.c +++ b/drivers/char/tpm/tpm1-cmd.c @@ -696,6 +696,16 @@ 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 971d46efaca5..bd20b9a61fc0 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); @@ -808,8 +808,10 @@ 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; @@ -826,11 +828,14 @@ 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; } @@ -839,7 +844,7 @@ 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) { @@ -848,17 +853,23 @@ 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); + + pcr_select_offset = memchr_inv(pcr_selection.pcr_select, 0, + pcr_selection.size_of_select); + if (pcr_select_offset) { + chip->allocated_banks[nr_alloc_banks] = hash_alg; + nr_alloc_banks++; + } + 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; 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