From: Tushar Sugandhi <tusharsu@linux.microsoft.com>
To: zohar@linux.ibm.com, stephen.smalley.work@gmail.com,
casey@schaufler-ca.com, agk@redhat.com, snitzer@redhat.com,
gmazyland@gmail.com, paul@paul-moore.com
Cc: tyhicks@linux.microsoft.com, sashal@kernel.org,
jmorris@namei.org, nramas@linux.microsoft.com,
linux-integrity@vger.kernel.org, selinux@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org, dm-devel@redhat.com
Subject: [PATCH v10 2/8] IMA: add support to measure buffer data hash
Date: Thu, 7 Jan 2021 20:07:02 -0800 [thread overview]
Message-ID: <20210108040708.8389-3-tusharsu@linux.microsoft.com> (raw)
In-Reply-To: <20210108040708.8389-1-tusharsu@linux.microsoft.com>
The original IMA buffer data measurement sizes were small (e.g. boot
command line), but the new buffer data measurement use cases have data
sizes that are a lot larger. Just as IMA measures the file data hash,
not the file data, IMA should similarly support the option for measuring
buffer data hash.
Introduce a boolean parameter to support measuring buffer data hash,
which would be much smaller, instead of the buffer itself.
Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
---
security/integrity/ima/ima.h | 3 +-
security/integrity/ima/ima_appraise.c | 2 +-
security/integrity/ima/ima_asymmetric_keys.c | 2 +-
security/integrity/ima/ima_main.c | 29 ++++++++++++++++----
security/integrity/ima/ima_queue_keys.c | 3 +-
5 files changed, 30 insertions(+), 9 deletions(-)
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index e5622ce8cbb1..0b4634515839 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -268,7 +268,8 @@ void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
struct ima_template_desc *template_desc);
void process_buffer_measurement(struct inode *inode, const void *buf, int size,
const char *eventname, enum ima_hooks func,
- int pcr, const char *func_data);
+ int pcr, const char *func_data,
+ bool buf_hash);
void ima_audit_measurement(struct integrity_iint_cache *iint,
const unsigned char *filename);
int ima_alloc_init_template(struct ima_event_data *event_data,
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index 8361941ee0a1..46ffa38bab12 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -352,7 +352,7 @@ int ima_check_blacklist(struct integrity_iint_cache *iint,
if ((rc == -EPERM) && (iint->flags & IMA_MEASURE))
process_buffer_measurement(NULL, digest, digestsize,
"blacklisted-hash", NONE,
- pcr, NULL);
+ pcr, NULL, false);
}
return rc;
diff --git a/security/integrity/ima/ima_asymmetric_keys.c b/security/integrity/ima/ima_asymmetric_keys.c
index 1c68c500c26f..a74095793936 100644
--- a/security/integrity/ima/ima_asymmetric_keys.c
+++ b/security/integrity/ima/ima_asymmetric_keys.c
@@ -60,5 +60,5 @@ void ima_post_key_create_or_update(struct key *keyring, struct key *key,
*/
process_buffer_measurement(NULL, payload, payload_len,
keyring->description, KEY_CHECK, 0,
- keyring->description);
+ keyring->description, false);
}
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index b4ed611cd2a4..494fb964497d 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -779,7 +779,7 @@ int ima_post_load_data(char *buf, loff_t size,
}
/*
- * process_buffer_measurement - Measure the buffer to ima log.
+ * process_buffer_measurement - Measure the buffer or the buffer data hash
* @inode: inode associated with the object being measured (NULL for KEY_CHECK)
* @buf: pointer to the buffer that needs to be added to the log.
* @size: size of buffer(in bytes).
@@ -787,12 +787,14 @@ int ima_post_load_data(char *buf, loff_t size,
* @func: IMA hook
* @pcr: pcr to extend the measurement
* @func_data: func specific data, may be NULL
+ * @buf_hash: measure buffer data hash
*
- * Based on policy, the buffer is measured into the ima log.
+ * Based on policy, either the buffer data or buffer data hash is measured
*/
void process_buffer_measurement(struct inode *inode, const void *buf, int size,
const char *eventname, enum ima_hooks func,
- int pcr, const char *func_data)
+ int pcr, const char *func_data,
+ bool buf_hash)
{
int ret = 0;
const char *audit_cause = "ENOMEM";
@@ -807,6 +809,8 @@ void process_buffer_measurement(struct inode *inode, const void *buf, int size,
struct ima_digest_data hdr;
char digest[IMA_MAX_DIGEST_SIZE];
} hash = {};
+ char digest_hash[IMA_MAX_DIGEST_SIZE];
+ int digest_hash_len = hash_digest_size[ima_hash_algo];
int violation = 0;
int action = 0;
u32 secid;
@@ -849,13 +853,27 @@ void process_buffer_measurement(struct inode *inode, const void *buf, int size,
goto out;
}
+ if (buf_hash) {
+ memcpy(digest_hash, hash.hdr.digest, digest_hash_len);
+
+ ret = ima_calc_buffer_hash(digest_hash, digest_hash_len,
+ iint.ima_hash);
+ if (ret < 0) {
+ audit_cause = "hashing_error";
+ goto out;
+ }
+
+ event_data.buf = digest_hash;
+ event_data.buf_len = digest_hash_len;
+ }
+
ret = ima_alloc_init_template(&event_data, &entry, template);
if (ret < 0) {
audit_cause = "alloc_entry";
goto out;
}
- ret = ima_store_template(entry, violation, NULL, buf, pcr);
+ ret = ima_store_template(entry, violation, NULL, event_data.buf, pcr);
if (ret < 0) {
audit_cause = "store_entry";
ima_free_template_entry(entry);
@@ -890,7 +908,8 @@ void ima_kexec_cmdline(int kernel_fd, const void *buf, int size)
return;
process_buffer_measurement(file_inode(f.file), buf, size,
- "kexec-cmdline", KEXEC_CMDLINE, 0, NULL);
+ "kexec-cmdline", KEXEC_CMDLINE, 0, NULL,
+ false);
fdput(f);
}
diff --git a/security/integrity/ima/ima_queue_keys.c b/security/integrity/ima/ima_queue_keys.c
index 69a8626a35c0..c2f2ad34f9b7 100644
--- a/security/integrity/ima/ima_queue_keys.c
+++ b/security/integrity/ima/ima_queue_keys.c
@@ -162,7 +162,8 @@ void ima_process_queued_keys(void)
entry->payload_len,
entry->keyring_name,
KEY_CHECK, 0,
- entry->keyring_name);
+ entry->keyring_name,
+ false);
list_del(&entry->list);
ima_free_key_entry(entry);
}
--
2.17.1
next prev parent reply other threads:[~2021-01-08 4:08 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-08 4:07 [PATCH v10 0/8] IMA: support for measuring kernel integrity critical data Tushar Sugandhi
2021-01-08 4:07 ` [PATCH v10 1/8] IMA: generalize keyring specific measurement constructs Tushar Sugandhi
2021-01-08 4:07 ` Tushar Sugandhi [this message]
2021-01-08 4:07 ` [PATCH v10 3/8] IMA: define a hook to measure kernel integrity critical data Tushar Sugandhi
2021-01-08 4:07 ` [PATCH v10 4/8] IMA: add policy rule to measure " Tushar Sugandhi
2021-01-08 4:07 ` [PATCH v10 5/8] IMA: limit critical data measurement based on a label Tushar Sugandhi
2021-01-14 2:09 ` Mimi Zohar
2021-01-14 17:57 ` Tushar Sugandhi
2021-01-08 4:07 ` [PATCH v10 6/8] IMA: extend critical data hook to limit the " Tushar Sugandhi
2021-01-08 4:07 ` [PATCH v10 7/8] IMA: define a builtin critical data measurement policy Tushar Sugandhi
2021-01-08 4:07 ` [PATCH v10 8/8] selinux: include a consumer of the new IMA critical data hook Tushar Sugandhi
2021-01-12 16:27 ` Paul Moore
2021-01-12 18:25 ` Lakshmi Ramasubramanian
2021-01-13 19:13 ` Mimi Zohar
2021-01-13 19:19 ` Paul Moore
2021-01-13 21:11 ` Mimi Zohar
2021-01-13 22:10 ` Paul Moore
2021-01-13 23:10 ` Mimi Zohar
2021-01-14 2:40 ` Paul Moore
2021-01-14 2:49 ` Mimi Zohar
2021-01-14 16:22 ` Lakshmi Ramasubramanian
2021-01-14 16:44 ` Mimi Zohar
2021-01-14 16:50 ` Mimi Zohar
2021-01-14 17:48 ` Lakshmi Ramasubramanian
2021-01-14 19:21 ` Lakshmi Ramasubramanian
2021-01-14 16:51 ` Paul Moore
2021-01-15 12:54 ` [PATCH v10 0/8] IMA: support for measuring kernel integrity critical data Mimi Zohar
2021-01-15 17:26 ` Tushar Sugandhi
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