From 6d94809af6b0830c4dfcad661535a5939bcb8a7d Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Wed, 25 Mar 2020 11:52:48 +0100 Subject: [PATCH] ima: Allocate and initialize tfm for each PCR bank This patch creates a crypto_shash structure for each allocated PCR bank and for SHA1 if a bank with that algorithm is not currently allocated. Reported-by: kbuild test robot Signed-off-by: Roberto Sassu Signed-off-by: Mimi Zohar --- security/integrity/ima/ima_crypto.c | 145 +++++++++++++++++++++++----- 1 file changed, 119 insertions(+), 26 deletions(-) diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c index fe02eb28b32b..ab1c05ad1314 100644 --- a/security/integrity/ima/ima_crypto.c +++ b/security/integrity/ima/ima_crypto.c @@ -57,14 +57,21 @@ MODULE_PARM_DESC(ahash_bufsize, "Maximum ahash buffer size"); static struct crypto_shash *ima_shash_tfm; static struct crypto_ahash *ima_ahash_tfm; +struct ima_algo_desc { + struct crypto_shash *tfm; + enum hash_algo algo; +}; + int ima_sha1_idx __ro_after_init; /* * Additional number of slots reserved, as needed, for SHA1 * and IMA default algo. */ -int ima_extra_slots __ro_after_init = 1; +int ima_extra_slots __ro_after_init; -int __init ima_init_crypto(void) +static struct ima_algo_desc *ima_algo_array; + +static int __init ima_init_ima_crypto(void) { long rc; @@ -83,26 +90,121 @@ int __init ima_init_crypto(void) static struct crypto_shash *ima_alloc_tfm(enum hash_algo algo) { struct crypto_shash *tfm = ima_shash_tfm; - int rc; + int rc, i; if (algo < 0 || algo >= HASH_ALGO__LAST) algo = ima_hash_algo; - if (algo != ima_hash_algo) { - tfm = crypto_alloc_shash(hash_algo_name[algo], 0, 0); - if (IS_ERR(tfm)) { - rc = PTR_ERR(tfm); - pr_err("Can not allocate %s (reason: %d)\n", - hash_algo_name[algo], rc); - } + if (algo == ima_hash_algo) + return tfm; + + for (i = 0; i < NR_BANKS(ima_tpm_chip) + ima_extra_slots; i++) + if (ima_algo_array[i].tfm && ima_algo_array[i].algo == algo) + return ima_algo_array[i].tfm; + + tfm = crypto_alloc_shash(hash_algo_name[algo], 0, 0); + if (IS_ERR(tfm)) { + rc = PTR_ERR(tfm); + pr_err("Can not allocate %s (reason: %d)\n", + hash_algo_name[algo], rc); } return tfm; } +int __init ima_init_crypto(void) +{ + enum hash_algo algo; + long rc; + int i; + + rc = ima_init_ima_crypto(); + if (rc) + return rc; + + ima_sha1_idx = -1; + + for (i = 0; i < NR_BANKS(ima_tpm_chip); i++) { + algo = ima_tpm_chip->allocated_banks[i].crypto_id; + if (algo == HASH_ALGO_SHA1) + ima_sha1_idx = i; + } + + if (ima_sha1_idx < 0) + ima_sha1_idx = NR_BANKS(ima_tpm_chip) + ima_extra_slots++; + + ima_algo_array = kcalloc(NR_BANKS(ima_tpm_chip) + ima_extra_slots, + sizeof(*ima_algo_array), GFP_KERNEL); + if (!ima_algo_array) { + rc = -ENOMEM; + goto out; + } + + for (i = 0; i < NR_BANKS(ima_tpm_chip); i++) { + algo = ima_tpm_chip->allocated_banks[i].crypto_id; + ima_algo_array[i].algo = algo; + + /* unknown TPM algorithm */ + if (algo == HASH_ALGO__LAST) + continue; + + if (algo == ima_hash_algo) { + ima_algo_array[i].tfm = ima_shash_tfm; + continue; + } + + ima_algo_array[i].tfm = ima_alloc_tfm(algo); + if (IS_ERR(ima_algo_array[i].tfm)) { + if (algo == HASH_ALGO_SHA1) { + rc = PTR_ERR(ima_algo_array[i].tfm); + ima_algo_array[i].tfm = NULL; + goto out_array; + } + + ima_algo_array[i].tfm = NULL; + } + } + + if (ima_sha1_idx >= NR_BANKS(ima_tpm_chip)) { + if (ima_hash_algo == HASH_ALGO_SHA1) { + ima_algo_array[ima_sha1_idx].tfm = ima_shash_tfm; + } else { + ima_algo_array[ima_sha1_idx].tfm = + ima_alloc_tfm(HASH_ALGO_SHA1); + if (IS_ERR(ima_algo_array[ima_sha1_idx].tfm)) { + rc = PTR_ERR(ima_algo_array[ima_sha1_idx].tfm); + goto out_array; + } + } + + ima_algo_array[ima_sha1_idx].algo = HASH_ALGO_SHA1; + } + + return 0; +out_array: + for (i = 0; i < NR_BANKS(ima_tpm_chip) + ima_extra_slots; i++) { + if (!ima_algo_array[i].tfm || + ima_algo_array[i].tfm == ima_shash_tfm) + continue; + + crypto_free_shash(ima_algo_array[i].tfm); + } +out: + crypto_free_shash(ima_shash_tfm); + return rc; +} + static void ima_free_tfm(struct crypto_shash *tfm) { - if (tfm != ima_shash_tfm) - crypto_free_shash(tfm); + int i; + + if (tfm == ima_shash_tfm) + return; + + for (i = 0; i < NR_BANKS(ima_tpm_chip) + ima_extra_slots; i++) + if (ima_algo_array[i].tfm == tfm) + return; + + crypto_free_shash(tfm); } /** @@ -472,14 +574,14 @@ int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash) */ static int ima_calc_field_array_hash_tfm(struct ima_field_data *field_data, struct ima_template_entry *entry, - struct crypto_shash *tfm) + int tfm_idx) { - SHASH_DESC_ON_STACK(shash, tfm); + SHASH_DESC_ON_STACK(shash, ima_algo_array[tfm_idx].tfm); struct ima_template_desc *td = entry->template_desc; int num_fields = entry->template_desc->num_fields; int rc, i; - shash->tfm = tfm; + shash->tfm = ima_algo_array[tfm_idx].tfm; rc = crypto_shash_init(shash); if (rc != 0) @@ -509,8 +611,7 @@ static int ima_calc_field_array_hash_tfm(struct ima_field_data *field_data, } if (!rc) - rc = crypto_shash_final(shash, - entry->digests[ima_sha1_idx].digest); + rc = crypto_shash_final(shash, entry->digests[tfm_idx].digest); return rc; } @@ -518,17 +619,9 @@ static int ima_calc_field_array_hash_tfm(struct ima_field_data *field_data, int ima_calc_field_array_hash(struct ima_field_data *field_data, struct ima_template_entry *entry) { - struct crypto_shash *tfm; int rc; - tfm = ima_alloc_tfm(HASH_ALGO_SHA1); - if (IS_ERR(tfm)) - return PTR_ERR(tfm); - - rc = ima_calc_field_array_hash_tfm(field_data, entry, tfm); - - ima_free_tfm(tfm); - + rc = ima_calc_field_array_hash_tfm(field_data, entry, ima_sha1_idx); return rc; }