lkml.org 
[lkml]   [2020]   [Mar]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v4 5/7] ima: Allocate and initialize tfm for each PCR bank
Date
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.

Changelog

v2:
- declare ima_init_ima_crypto() as static
- replace ima_num_template_digests with
NR_BANKS(ima_tpm_chip) + ima_extra_slots (suggested by Mimi)
- use ima_sha1_idx to access ima_algo_array elements in ima_init_crypto()

v1:
- determine ima_num_template_digests before allocating ima_algo_array
(suggested by Mimi)
- replace kmalloc_array() with kcalloc() in ima_init_crypto() (suggested by
Mimi)
- check tfm first in ima_alloc_tfm()
- check if ima_tpm_chip is NULL

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
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;
}

--
2.17.1
\
 
 \ /
  Last update: 2020-03-25 11:56    [W:0.082 / U:4.392 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site