From: Roberto Sassu <roberto.sassu@huawei.com>
To: <zohar@linux.ibm.com>, <James.Bottomley@HansenPartnership.com>,
<jarkko.sakkinen@linux.intel.com>
Cc: <linux-integrity@vger.kernel.org>,
<linux-security-module@vger.kernel.org>,
<linux-kernel@vger.kernel.org>, <silviu.vlasceanu@huawei.com>,
Roberto Sassu <roberto.sassu@huawei.com>
Subject: [PATCH v2 8/8] ima: Use ima_hash_algo for collision detection in the measurement list
Date: Wed, 5 Feb 2020 11:33:17 +0100 [thread overview]
Message-ID: <20200205103317.29356-9-roberto.sassu@huawei.com> (raw)
In-Reply-To: <20200205103317.29356-1-roberto.sassu@huawei.com>
Before calculating a digest for each PCR bank, collisions were detected
with a SHA1 digest. This patch includes ima_hash_algo among the algorithms
used to calculate the template digest and checks collisions on that digest.
Changelog
v1:
- increment ima_num_template_digests before kcalloc() (suggested by Mimi)
- check if ima_tpm_chip is NULL
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
security/integrity/ima/ima.h | 1 +
security/integrity/ima/ima_crypto.c | 20 ++++++++++++++++++--
security/integrity/ima/ima_queue.c | 8 ++++----
3 files changed, 23 insertions(+), 6 deletions(-)
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 4843077dc9e8..23d63bb96d2c 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -51,6 +51,7 @@ extern int ima_policy_flag;
/* set during initialization */
extern int ima_hash_algo;
extern int ima_sha1_idx;
+extern int ima_hash_algo_idx;
extern int ima_num_template_digests;
extern int ima_appraise;
extern struct tpm_chip *ima_tpm_chip;
diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index 1ee813d33bdc..f391ee3412b9 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -65,6 +65,7 @@ struct ima_algo_desc {
};
int ima_sha1_idx;
+int ima_hash_algo_idx;
int ima_num_template_digests;
static struct ima_algo_desc *ima_algo_array;
@@ -123,16 +124,26 @@ int __init ima_init_crypto(void)
nr_allocated_banks = ima_tpm_chip->nr_allocated_banks;
ima_sha1_idx = -1;
+ ima_hash_algo_idx = -1;
ima_num_template_digests = nr_allocated_banks;
for (i = 0; i < nr_allocated_banks; i++) {
algo = ima_tpm_chip->allocated_banks[i].crypto_id;
if (algo == HASH_ALGO_SHA1)
ima_sha1_idx = i;
+
+ if (algo == ima_hash_algo)
+ ima_hash_algo_idx = i;
}
- if (ima_sha1_idx < 0)
+ if (ima_sha1_idx < 0) {
ima_sha1_idx = ima_num_template_digests++;
+ if (ima_hash_algo == HASH_ALGO_SHA1)
+ ima_hash_algo_idx = ima_sha1_idx;
+ }
+
+ if (ima_hash_algo_idx < 0)
+ ima_hash_algo_idx = ima_num_template_digests++;
ima_algo_array = kcalloc(ima_num_template_digests,
sizeof(*ima_algo_array), GFP_KERNEL);
@@ -173,7 +184,12 @@ int __init ima_init_crypto(void)
goto out_array;
}
- ima_algo_array[i].algo = HASH_ALGO_SHA1;
+ ima_algo_array[i++].algo = HASH_ALGO_SHA1;
+ }
+
+ if (ima_hash_algo_idx >= nr_allocated_banks) {
+ ima_algo_array[i].tfm = ima_shash_tfm;
+ ima_algo_array[i].algo = ima_hash_algo;
}
return 0;
diff --git a/security/integrity/ima/ima_queue.c b/security/integrity/ima/ima_queue.c
index 7f7509774b85..58983d0f0214 100644
--- a/security/integrity/ima/ima_queue.c
+++ b/security/integrity/ima/ima_queue.c
@@ -57,8 +57,8 @@ static struct ima_queue_entry *ima_lookup_digest_entry(u8 *digest_value,
key = ima_hash_key(digest_value);
rcu_read_lock();
hlist_for_each_entry_rcu(qe, &ima_htable.queue[key], hnext) {
- rc = memcmp(qe->entry->digests[ima_sha1_idx].digest,
- digest_value, TPM_DIGEST_SIZE);
+ rc = memcmp(qe->entry->digests[ima_hash_algo_idx].digest,
+ digest_value, hash_digest_size[ima_hash_algo]);
if ((rc == 0) && (qe->entry->pcr == pcr)) {
ret = qe;
break;
@@ -110,7 +110,7 @@ static int ima_add_digest_entry(struct ima_template_entry *entry,
atomic_long_inc(&ima_htable.len);
if (update_htable) {
- key = ima_hash_key(entry->digests[ima_sha1_idx].digest);
+ key = ima_hash_key(entry->digests[ima_hash_algo_idx].digest);
hlist_add_head_rcu(&qe->hnext, &ima_htable.queue[key]);
}
@@ -162,7 +162,7 @@ int ima_add_template_entry(struct ima_template_entry *entry, int violation,
const char *op, struct inode *inode,
const unsigned char *filename)
{
- u8 *digest = entry->digests[ima_sha1_idx].digest;
+ u8 *digest = entry->digests[ima_hash_algo_idx].digest;
struct tpm_digest *digests_arg = entry->digests;
const char *audit_cause = "hash_added";
char tpm_audit_cause[AUDIT_CAUSE_LEN_MAX];
--
2.17.1
next prev parent reply other threads:[~2020-02-05 10:36 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-05 10:33 [PATCH v2 0/8] ima: support stronger algorithms for attestation Roberto Sassu
2020-02-05 10:33 ` [PATCH v2 1/8] tpm: Initialize crypto_id of allocated_banks to HASH_ALGO__LAST Roberto Sassu
2020-02-05 21:57 ` Jarkko Sakkinen
2020-02-05 10:33 ` [PATCH v2 2/8] ima: Switch to ima_hash_algo for boot aggregate Roberto Sassu
2020-02-05 20:41 ` Mimi Zohar
2020-02-06 9:33 ` Roberto Sassu
2020-02-05 21:00 ` Mimi Zohar
2020-02-06 9:36 ` Roberto Sassu
2020-02-06 12:17 ` Mimi Zohar
2020-02-06 12:28 ` Roberto Sassu
2020-02-06 12:31 ` Mimi Zohar
2020-02-05 10:33 ` [PATCH v2 3/8] ima: Evaluate error in init_ima() Roberto Sassu
2020-02-05 10:39 ` Roberto Sassu
2020-02-05 10:33 ` [PATCH v2 4/8] ima: Store template digest directly in ima_template_entry Roberto Sassu
2020-02-05 10:33 ` [PATCH v2 5/8] ima: Switch to dynamically allocated buffer for template digests Roberto Sassu
2020-02-05 16:39 ` Roberto Sassu
2020-02-06 16:08 ` Mimi Zohar
2020-02-06 16:27 ` Roberto Sassu
2020-02-06 16:33 ` Mimi Zohar
2020-02-06 16:36 ` Roberto Sassu
2020-02-05 10:33 ` [PATCH v2 6/8] ima: Allocate and initialize tfm for each PCR bank Roberto Sassu
2020-02-05 23:41 ` kbuild test robot
2020-02-05 23:41 ` [RFC PATCH] ima: ima_init_ima_crypto() can be static kbuild test robot
2020-02-05 10:33 ` [PATCH v2 7/8] ima: Calculate and extend PCR with digests in ima_template_entry Roberto Sassu
2020-02-05 10:33 ` Roberto Sassu [this message]
2020-03-02 1:22 ` [ima] 9165b814d2: BUG:kernel_NULL_pointer_dereference,address kernel test robot
2020-03-02 9:46 ` Roberto Sassu
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200205103317.29356-9-roberto.sassu@huawei.com \
--to=roberto.sassu@huawei.com \
--cc=James.Bottomley@HansenPartnership.com \
--cc=jarkko.sakkinen@linux.intel.com \
--cc=linux-integrity@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=silviu.vlasceanu@huawei.com \
--cc=zohar@linux.ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).