[ck] [PATCH 13/17] tpm: pass an array of tpm_extend_digest structures to tpm_pcr_extend()

From: Roberto Sassu &lt;roberto.sassu(a)huawei.com&gt; commit 0b6cf6b97b7ef1fa3c7fefab0cac897a1c4a3400 upstream. Currently, tpm_pcr_extend() accepts as an input only a SHA1 digest. This patch replaces the hash parameter of tpm_pcr_extend() with an array of tpm_digest structures, so that the caller can provide a digest for each PCR bank currently allocated in the TPM. tpm_pcr_extend() will not extend banks for which no digest was provided, as it happened before this patch, but instead it requires that callers provide the full set of digests. Since the number of digests will always be chip->nr_allocated_banks, the count parameter has been removed. Due to the API change, ima_pcr_extend() and pcrlock() have been modified. Since the number of allocated banks is not known in advance, the memory for the digests must be dynamically allocated. To avoid performance degradation and to avoid that a PCR extend is not done due to lack of memory, the array of tpm_digest structures is allocated by the users of the TPM driver at initialization time. Signed-off-by: Roberto Sassu &lt;roberto.sassu(a)huawei.com&gt; Reviewed-by: Jarkko Sakkinen &lt;jarkko.sakkinen(a)linux.intel.com&gt; Tested-by: Jarkko Sakkinen &lt;jarkko.sakkinen(a)linux.intel.com&gt; Tested-by: Mimi Zohar &lt;zohar(a)linux.ibm.com&gt; (on x86 for TPM 1.2 & PTT TPM 2.0) Signed-off-by: Jarkko Sakkinen &lt;jarkko.sakkinen(a)linux.intel.com&gt; Signed-off-by: mayuanchen &lt;mayuanchen(a)hygon.cn&gt; Change-Id: I38e8dd24de046778c3f0313d497b3f507139dbd7 --- drivers/char/tpm/tpm-interface.c | 30 ++++++++-------------- drivers/char/tpm/tpm.h | 2 +- drivers/char/tpm/tpm2-cmd.c | 10 +++----- include/linux/tpm.h | 5 ++-- security/integrity/ima/ima.h | 1 + security/integrity/ima/ima_init.c | 4 +++ security/integrity/ima/ima_queue.c | 27 +++++++++++++++++++- security/keys/trusted.c | 41 ++++++++++++++++++++++++------ 8 files changed, 82 insertions(+), 38 deletions(-) diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index 2b052c9f1f2d..b5df4dd1aa57 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -1040,42 +1040,34 @@ static int tpm1_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8 *hash, * tpm_pcr_extend - extend a PCR value in SHA1 bank. * @chip: a &struct tpm_chip instance, %NULL for the default chip * @pcr_idx: the PCR to be retrieved - * @hash: the hash value used to extend the PCR value + * @digests: array of tpm_digest structures used to extend PCRs * - * Note: with TPM 2.0 extends also those banks for which no digest was - * specified in order to prevent malicious use of those PCR banks. + * Note: callers must pass a digest for every allocated PCR bank, in the same + * order of the banks in chip->allocated_banks. * * Return: same as with tpm_transmit_cmd() */ -int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8 *hash) +int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, + struct tpm_digest *digests) { int rc; - struct tpm_digest *digest_list; int i; chip = tpm_find_get_ops(chip); if (!chip) return -ENODEV; - if (chip->flags & TPM_CHIP_FLAG_TPM2) { - digest_list = kcalloc(chip->nr_allocated_banks, - sizeof(*digest_list), GFP_KERNEL); - if (!digest_list) - return -ENOMEM; - - for (i = 0; i < chip->nr_allocated_banks; i++) { - digest_list[i].alg_id = chip->allocated_banks[i].alg_id; - memcpy(digest_list[i].digest, hash, TPM_DIGEST_SIZE); - } + for (i = 0; i < chip->nr_allocated_banks; i++) + if (digests[i].alg_id != chip->allocated_banks[i].alg_id) + return -EINVAL; - rc = tpm2_pcr_extend(chip, pcr_idx, chip->nr_allocated_banks, - digest_list); - kfree(digest_list); + if (chip->flags & TPM_CHIP_FLAG_TPM2) { + rc = tpm2_pcr_extend(chip, pcr_idx, digests); tpm_put_ops(chip); return rc; } - rc = tpm1_pcr_extend(chip, pcr_idx, hash, + rc = tpm1_pcr_extend(chip, pcr_idx, digests[0].digest, "attempting extend a PCR value"); tpm_put_ops(chip); return rc; diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 3171c80e3546..a690beaddff9 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -475,7 +475,7 @@ static inline u32 tpm2_rc_value(u32 rc) int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx, struct tpm_digest *digest, u16 *digest_size_ptr); -int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, u32 count, +int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, struct tpm_digest *digests); int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max); void tpm2_flush_context_cmd(struct tpm_chip *chip, u32 handle, diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index c29714bc31e2..154504daa834 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -256,12 +256,11 @@ struct tpm2_null_auth_area { * * @chip: TPM chip to use. * @pcr_idx: index of the PCR. - * @count: number of digests passed. * @digests: list of pcr banks and corresponding digest values to extend. * * Return: Same as with tpm_transmit_cmd. */ -int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, u32 count, +int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, struct tpm_digest *digests) { struct tpm_buf buf; @@ -269,9 +268,6 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, u32 count, int rc; int i; - if (count > chip->nr_allocated_banks) - return -EINVAL; - rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_PCR_EXTEND); if (rc) return rc; @@ -286,9 +282,9 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, u32 count, tpm_buf_append_u32(&buf, sizeof(struct tpm2_null_auth_area)); tpm_buf_append(&buf, (const unsigned char *)&auth_area, sizeof(auth_area)); - tpm_buf_append_u32(&buf, count); + tpm_buf_append_u32(&buf, chip->nr_allocated_banks); - for (i = 0; i < count; i++) { + for (i = 0; i < chip->nr_allocated_banks; i++) { tpm_buf_append_u16(&buf, digests[i].alg_id); tpm_buf_append(&buf, (const unsigned char *)&digests[i].digest, chip->allocated_banks[i].digest_size); diff --git a/include/linux/tpm.h b/include/linux/tpm.h index 920e7a455636..c94a8e7d1704 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -170,7 +170,8 @@ struct tpm_chip { extern int tpm_is_tpm2(struct tpm_chip *chip); extern int tpm_pcr_read(struct tpm_chip *chip, u32 pcr_idx, struct tpm_digest *digest); -extern int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8 *hash); +extern int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, + struct tpm_digest *digests); extern int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen); extern int tpm_get_random(struct tpm_chip *chip, u8 *data, size_t max); extern int tpm_seal_trusted(struct tpm_chip *chip, @@ -193,7 +194,7 @@ static inline int tpm_pcr_read(struct tpm_chip *chip, u32 pcr_idx, } static inline int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, - const u8 *hash) + struct tpm_digest *digests) { return -ENODEV; } diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 67db9d9454ca..4e211d85f32e 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -153,6 +153,7 @@ int ima_measurements_show(struct seq_file *m, void *v); unsigned long ima_get_binary_runtime_size(void); int ima_init_template(void); void ima_init_template_list(void); +int __init ima_init_digests(void); /* * used to protect h_table and sha_table diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c index faac9ecaa0ae..a9508ef781a7 100644 --- a/security/integrity/ima/ima_init.c +++ b/security/integrity/ima/ima_init.c @@ -123,8 +123,12 @@ int __init ima_init(void) if (rc != 0) return rc; + /* It can be called before ima_init_digests(), it does not use TPM. */ ima_load_kexec_buffer(); + rc = ima_init_digests(); + if (rc != 0) + return rc; rc = ima_add_boot_aggregate(); /* boot aggregate must be first entry */ if (rc != 0) return rc; diff --git a/security/integrity/ima/ima_queue.c b/security/integrity/ima/ima_queue.c index b186819bd5aa..b4ee95bad1da 100644 --- a/security/integrity/ima/ima_queue.c +++ b/security/integrity/ima/ima_queue.c @@ -28,6 +28,9 @@ #define AUDIT_CAUSE_LEN_MAX 32 +/* pre-allocated array of tpm_digest structures to extend a PCR */ +static struct tpm_digest *digests; + LIST_HEAD(ima_measurements); /* list of all measurements */ #ifdef CONFIG_IMA_KEXEC static unsigned long binary_runtime_size; @@ -141,11 +144,15 @@ unsigned long ima_get_binary_runtime_size(void) static int ima_pcr_extend(const u8 *hash, int pcr) { int result = 0; + int i; if (!ima_tpm_chip) return result; - result = tpm_pcr_extend(ima_tpm_chip, pcr, hash); + for (i = 0; i < ima_tpm_chip->nr_allocated_banks; i++) + memcpy(digests[i].digest, hash, TPM_DIGEST_SIZE); + + result = tpm_pcr_extend(ima_tpm_chip, pcr, digests); if (result != 0) pr_err("Error Communicating to TPM chip, result: %d\n", result); return result; @@ -212,3 +219,21 @@ int ima_restore_measurement_entry(struct ima_template_entry *entry) mutex_unlock(&ima_extend_list_mutex); return result; } + +int __init ima_init_digests(void) +{ + int i; + + if (!ima_tpm_chip) + return 0; + + digests = kcalloc(ima_tpm_chip->nr_allocated_banks, sizeof(*digests), + GFP_NOFS); + if (!digests) + return -ENOMEM; + + for (i = 0; i < ima_tpm_chip->nr_allocated_banks; i++) + digests[i].alg_id = ima_tpm_chip->allocated_banks[i].alg_id; + + return 0; +} diff --git a/security/keys/trusted.c b/security/keys/trusted.c index a08a41deda81..fb934887b2d2 100644 --- a/security/keys/trusted.c +++ b/security/keys/trusted.c @@ -35,6 +35,7 @@ static const char hmac_alg[] = "hmac(sha1)"; static const char hash_alg[] = "sha1"; static struct tpm_chip *chip; +static struct tpm_digest *digests; struct sdesc { struct shash_desc shash; @@ -377,15 +378,10 @@ static int trusted_tpm_send(unsigned char *cmd, size_t buflen) */ static int pcrlock(const int pcrnum) { - unsigned char hash[SHA1_DIGEST_SIZE]; - int ret; - if (!capable(CAP_SYS_ADMIN)) return -EPERM; - ret = tpm_get_random(chip, hash, SHA1_DIGEST_SIZE); - if (ret != SHA1_DIGEST_SIZE) - return ret; - return tpm_pcr_extend(chip, pcrnum, hash) ? -EINVAL : 0; + + return tpm_pcr_extend(chip, pcrnum, digests) ? -EINVAL : 0; } /* @@ -1218,6 +1214,29 @@ static int __init trusted_shash_alloc(void) return ret; } +static int __init init_digests(void) +{ + u8 digest[TPM_MAX_DIGEST_SIZE]; + int ret; + int i; + + ret = tpm_get_random(chip, digest, TPM_MAX_DIGEST_SIZE); + if (ret < 0) + return ret; + if (ret < TPM_MAX_DIGEST_SIZE) + return -EFAULT; + + digests = kcalloc(chip->nr_allocated_banks, sizeof(*digests), + GFP_KERNEL); + if (!digests) + return -ENOMEM; + + for (i = 0; i < chip->nr_allocated_banks; i++) + memcpy(digests[i].digest, digest, TPM_MAX_DIGEST_SIZE); + + return 0; +} + static int __init init_trusted(void) { int ret; @@ -1225,15 +1244,20 @@ static int __init init_trusted(void) chip = tpm_default_chip(); if (!chip) return -ENOENT; - ret = trusted_shash_alloc(); + ret = init_digests(); if (ret < 0) goto err_put; + ret = trusted_shash_alloc(); + if (ret < 0) + goto err_free; ret = register_key_type(&key_type_trusted); if (ret < 0) goto err_release; return 0; err_release: trusted_shash_release(); +err_free: + kfree(digests); err_put: put_device(&chip->dev); return ret; @@ -1242,6 +1266,7 @@ static int __init init_trusted(void) static void __exit cleanup_trusted(void) { put_device(&chip->dev); + kfree(digests); trusted_shash_release(); unregister_key_type(&key_type_trusted); } -- 2.17.1