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 <lkp@intel.com>
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
This commit is contained in:
Roberto Sassu 2020-03-25 11:52:48 +01:00 committed by Mimi Zohar
parent aa724fe18a
commit 6d94809af6
1 changed files with 119 additions and 26 deletions

View File

@ -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;
}