* [PATCH v4 0/3] ima: Provide more info about buffer measurement
@ 2021-07-23 8:53 Roberto Sassu
2021-07-23 8:53 ` [PATCH v4 1/3] ima: Introduce ima_get_current_hash_algo() Roberto Sassu
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Roberto Sassu @ 2021-07-23 8:53 UTC (permalink / raw)
To: zohar, paul
Cc: stephen.smalley.work, prsriva02, tusharsu, nramas,
linux-integrity, linux-security-module, linux-kernel, selinux,
Roberto Sassu
This patch set provides more information about buffer measurement. It
requires the modification of the existing functions
ima_measure_critical_data() and process_buffer_measurement() as, unlike
for files, there is no integrity_iint_cache structure that can be used to
store and retrieve at a later time the buffer measurement (there is no
index, for files it is the inode number).
First, this patch set introduces the new function
ima_get_current_hash_algo(), to obtain the algorithm used to calculate the
buffer digest (patch 1).
Second, it changes the type of return value of ima_measure_critical_data()
and process_buffer_measurement() from void to int, to signal to the callers
whether or not the buffer has been measured, or just the digest has been
calculated and written to the supplied location (patch 2).
Lastly, it adds two new parameters to the functions above ('digest' and
'digest_len'), so that those functions can write the buffer digest to the
location supplied by the callers (patch 3).
This patch set replaces the patch 'ima: Add digest, algo, measured
parameters to ima_measure_critical_data()' in:
https://lore.kernel.org/linux-integrity/20210625165614.2284243-1-roberto.sassu@huawei.com/
Changelog
v3:
- explain better the motivation for the patches (suggested by Mimi)
v2:
- remove assignments of ima_measure_critical_data() and
process_buffer_measurement() return values (suggested by Lakshmi)
v1:
- add digest_len parameter to ima_measure_critical_data() and
process_buffer_measurement() (suggested by Lakshmi)
- fix doc formatting issues
Huawei Digest Lists patch set:
- introduce ima_get_current_hash_algo() (suggested by Mimi)
- remove algo and measured parameters from ima_measure_critical_data() and
process_buffer_measurement() (suggested by Mimi)
- return an integer from ima_measure_critical_data() and
process_buffer_measurement() (suggested by Mimi)
- correctly check when process_buffer_measurement() should return earlier
Roberto Sassu (3):
ima: Introduce ima_get_current_hash_algo()
ima: Return int in the functions to measure a buffer
ima: Add digest and digest_len params to the functions to measure a
buffer
include/linux/ima.h | 23 +++++--
security/integrity/ima/ima.h | 10 +--
security/integrity/ima/ima_appraise.c | 2 +-
security/integrity/ima/ima_asymmetric_keys.c | 2 +-
security/integrity/ima/ima_init.c | 3 +-
security/integrity/ima/ima_main.c | 67 ++++++++++++++------
security/integrity/ima/ima_queue_keys.c | 2 +-
security/selinux/ima.c | 6 +-
8 files changed, 78 insertions(+), 37 deletions(-)
--
2.25.1
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v4 1/3] ima: Introduce ima_get_current_hash_algo()
2021-07-23 8:53 [PATCH v4 0/3] ima: Provide more info about buffer measurement Roberto Sassu
@ 2021-07-23 8:53 ` Roberto Sassu
2021-07-23 12:49 ` Mimi Zohar
2021-07-23 8:53 ` [PATCH v4 2/3] ima: Return int in the functions to measure a buffer Roberto Sassu
2021-07-23 8:53 ` [PATCH v4 3/3] ima: Add digest and digest_len params to " Roberto Sassu
2 siblings, 1 reply; 6+ messages in thread
From: Roberto Sassu @ 2021-07-23 8:53 UTC (permalink / raw)
To: zohar, paul
Cc: stephen.smalley.work, prsriva02, tusharsu, nramas,
linux-integrity, linux-security-module, linux-kernel, selinux,
Roberto Sassu
Buffer measurements, unlike file measurements, are not accessible after the
measurement is done, as buffers are not suitable for use with the
integrity_iint_cache structure (there is no index, for files it is the
inode number). In the subsequent patches, the measurement (digest) will be
returned directly by the functions that perform the buffer measurement,
ima_measure_critical_data() and process_buffer_measurement().
A caller of those functions also needs to know the algorithm used to
calculate the digest. Instead of adding the algorithm as a new parameter to
the functions, this patch provides it separately with the new function
ima_get_current_hash_algo().
Since the hash algorithm does not change after the IMA setup phase, there
is no risk of races (obtaining a digest calculated with a different
algorithm than the one returned).
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
---
include/linux/ima.h | 7 +++++++
security/integrity/ima/ima_main.c | 5 +++++
2 files changed, 12 insertions(+)
diff --git a/include/linux/ima.h b/include/linux/ima.h
index 61d5723ec303..81e830d01ced 100644
--- a/include/linux/ima.h
+++ b/include/linux/ima.h
@@ -11,9 +11,11 @@
#include <linux/fs.h>
#include <linux/security.h>
#include <linux/kexec.h>
+#include <crypto/hash_info.h>
struct linux_binprm;
#ifdef CONFIG_IMA
+extern enum hash_algo ima_get_current_hash_algo(void);
extern int ima_bprm_check(struct linux_binprm *bprm);
extern int ima_file_check(struct file *file, int mask);
extern void ima_post_create_tmpfile(struct user_namespace *mnt_userns,
@@ -64,6 +66,11 @@ static inline const char * const *arch_get_ima_policy(void)
#endif
#else
+static inline enum hash_algo ima_get_current_hash_algo(void)
+{
+ return HASH_ALGO__LAST;
+}
+
static inline int ima_bprm_check(struct linux_binprm *bprm)
{
return 0;
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 287b90509006..8ef1fa357e0c 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -76,6 +76,11 @@ static int __init hash_setup(char *str)
}
__setup("ima_hash=", hash_setup);
+enum hash_algo ima_get_current_hash_algo(void)
+{
+ return ima_hash_algo;
+}
+
/* Prevent mmap'ing a file execute that is already mmap'ed write */
static int mmap_violation_check(enum ima_hooks func, struct file *file,
char **pathbuf, const char **pathname,
--
2.25.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v4 2/3] ima: Return int in the functions to measure a buffer
2021-07-23 8:53 [PATCH v4 0/3] ima: Provide more info about buffer measurement Roberto Sassu
2021-07-23 8:53 ` [PATCH v4 1/3] ima: Introduce ima_get_current_hash_algo() Roberto Sassu
@ 2021-07-23 8:53 ` Roberto Sassu
2021-07-23 8:53 ` [PATCH v4 3/3] ima: Add digest and digest_len params to " Roberto Sassu
2 siblings, 0 replies; 6+ messages in thread
From: Roberto Sassu @ 2021-07-23 8:53 UTC (permalink / raw)
To: zohar, paul
Cc: stephen.smalley.work, prsriva02, tusharsu, nramas,
linux-integrity, linux-security-module, linux-kernel, selinux,
Roberto Sassu
ima_measure_critical_data() and process_buffer_measurement() currently
don't return a result as, unlike appraisal-related functions, the result is
not used by callers to deny an operation. Measurement-related functions
instead rely on the audit subsystem to notify the system administrator when
an error occurs.
However, ima_measure_critical_data() and process_buffer_measurement() are a
special case, as these are the only functions that can return a buffer
measurement (for files, there is ima_file_hash()). In a subsequent patch,
they will be modified to return the calculated digest.
In preparation to return the result of the digest calculation, this patch
modifies the return type from void to int, and returns 0 if the buffer has
been successfully measured, a negative value otherwise.
Given that the result of the measurement is still not necessary, this patch
does not modify the behavior of existing callers by processing the returned
value. For those, the return value is ignored.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Acked-by: Paul Moore <paul@paul-moore.com> (for the SELinux bits)
---
include/linux/ima.h | 15 +++++++-----
security/integrity/ima/ima.h | 10 ++++----
security/integrity/ima/ima_main.c | 40 ++++++++++++++++++-------------
3 files changed, 37 insertions(+), 28 deletions(-)
diff --git a/include/linux/ima.h b/include/linux/ima.h
index 81e830d01ced..60492263aa64 100644
--- a/include/linux/ima.h
+++ b/include/linux/ima.h
@@ -35,10 +35,10 @@ extern void ima_post_path_mknod(struct user_namespace *mnt_userns,
extern int ima_file_hash(struct file *file, char *buf, size_t buf_size);
extern int ima_inode_hash(struct inode *inode, char *buf, size_t buf_size);
extern void ima_kexec_cmdline(int kernel_fd, const void *buf, int size);
-extern void ima_measure_critical_data(const char *event_label,
- const char *event_name,
- const void *buf, size_t buf_len,
- bool hash);
+extern int ima_measure_critical_data(const char *event_label,
+ const char *event_name,
+ const void *buf, size_t buf_len,
+ bool hash);
#ifdef CONFIG_IMA_APPRAISE_BOOTPARAM
extern void ima_appraise_parse_cmdline(void);
@@ -144,10 +144,13 @@ static inline int ima_inode_hash(struct inode *inode, char *buf, size_t buf_size
static inline void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) {}
-static inline void ima_measure_critical_data(const char *event_label,
+static inline int ima_measure_critical_data(const char *event_label,
const char *event_name,
const void *buf, size_t buf_len,
- bool hash) {}
+ bool hash)
+{
+ return -ENOENT;
+}
#endif /* CONFIG_IMA */
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index f0e448ed1f9f..03db221324c3 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -264,11 +264,11 @@ void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
struct evm_ima_xattr_data *xattr_value,
int xattr_len, const struct modsig *modsig, int pcr,
struct ima_template_desc *template_desc);
-void process_buffer_measurement(struct user_namespace *mnt_userns,
- struct inode *inode, const void *buf, int size,
- const char *eventname, enum ima_hooks func,
- int pcr, const char *func_data,
- bool buf_hash);
+int process_buffer_measurement(struct user_namespace *mnt_userns,
+ struct inode *inode, const void *buf, int size,
+ const char *eventname, enum ima_hooks func,
+ 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_main.c b/security/integrity/ima/ima_main.c
index 8ef1fa357e0c..b512c06d8ee1 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -827,7 +827,7 @@ int ima_post_load_data(char *buf, loff_t size,
return 0;
}
-/*
+/**
* process_buffer_measurement - Measure the buffer or the buffer data hash
* @mnt_userns: user namespace of the mount the inode was found from
* @inode: inode associated with the object being measured (NULL for KEY_CHECK)
@@ -840,12 +840,15 @@ int ima_post_load_data(char *buf, loff_t size,
* @buf_hash: measure buffer data hash
*
* Based on policy, either the buffer data or buffer data hash is measured
+ *
+ * Return: 0 if the buffer has been successfully measured, a negative value
+ * otherwise.
*/
-void process_buffer_measurement(struct user_namespace *mnt_userns,
- struct inode *inode, const void *buf, int size,
- const char *eventname, enum ima_hooks func,
- int pcr, const char *func_data,
- bool buf_hash)
+int process_buffer_measurement(struct user_namespace *mnt_userns,
+ struct inode *inode, const void *buf, int size,
+ const char *eventname, enum ima_hooks func,
+ int pcr, const char *func_data,
+ bool buf_hash)
{
int ret = 0;
const char *audit_cause = "ENOMEM";
@@ -867,7 +870,7 @@ void process_buffer_measurement(struct user_namespace *mnt_userns,
u32 secid;
if (!ima_policy_flag)
- return;
+ return -ENOENT;
template = ima_template_desc_buf();
if (!template) {
@@ -889,7 +892,7 @@ void process_buffer_measurement(struct user_namespace *mnt_userns,
secid, 0, func, &pcr, &template,
func_data);
if (!(action & IMA_MEASURE))
- return;
+ return -ENOENT;
}
if (!pcr)
@@ -937,7 +940,7 @@ void process_buffer_measurement(struct user_namespace *mnt_userns,
func_measure_str(func),
audit_cause, ret, 0, ret);
- return;
+ return ret;
}
/**
@@ -977,18 +980,21 @@ void ima_kexec_cmdline(int kernel_fd, const void *buf, int size)
* and extend the pcr. Examples of critical data could be various data
* structures, policies, and states stored in kernel memory that can
* impact the integrity of the system.
+ *
+ * Return: 0 if the buffer has been successfully measured, a negative value
+ * otherwise.
*/
-void ima_measure_critical_data(const char *event_label,
- const char *event_name,
- const void *buf, size_t buf_len,
- bool hash)
+int ima_measure_critical_data(const char *event_label,
+ const char *event_name,
+ const void *buf, size_t buf_len,
+ bool hash)
{
if (!event_name || !event_label || !buf || !buf_len)
- return;
+ return -ENOPARAM;
- process_buffer_measurement(&init_user_ns, NULL, buf, buf_len, event_name,
- CRITICAL_DATA, 0, event_label,
- hash);
+ return process_buffer_measurement(&init_user_ns, NULL, buf, buf_len,
+ event_name, CRITICAL_DATA, 0,
+ event_label, hash);
}
static int __init init_ima(void)
--
2.25.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v4 3/3] ima: Add digest and digest_len params to the functions to measure a buffer
2021-07-23 8:53 [PATCH v4 0/3] ima: Provide more info about buffer measurement Roberto Sassu
2021-07-23 8:53 ` [PATCH v4 1/3] ima: Introduce ima_get_current_hash_algo() Roberto Sassu
2021-07-23 8:53 ` [PATCH v4 2/3] ima: Return int in the functions to measure a buffer Roberto Sassu
@ 2021-07-23 8:53 ` Roberto Sassu
2 siblings, 0 replies; 6+ messages in thread
From: Roberto Sassu @ 2021-07-23 8:53 UTC (permalink / raw)
To: zohar, paul
Cc: stephen.smalley.work, prsriva02, tusharsu, nramas,
linux-integrity, linux-security-module, linux-kernel, selinux,
Roberto Sassu
This patch performs the final modification necessary to pass the buffer
measurement to callers, so that they provide a functionality similar to
ima_file_hash(). It adds the 'digest' and 'digest_len' parameters to
ima_measure_critical_data() and process_buffer_measurement().
These functions calculate the digest even if there is no suitable rule in
the IMA policy and, in this case, they simply return 1 before generating a
new measurement entry.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
---
include/linux/ima.h | 5 +--
security/integrity/ima/ima.h | 2 +-
security/integrity/ima/ima_appraise.c | 2 +-
security/integrity/ima/ima_asymmetric_keys.c | 2 +-
security/integrity/ima/ima_init.c | 3 +-
security/integrity/ima/ima_main.c | 36 ++++++++++++++------
security/integrity/ima/ima_queue_keys.c | 2 +-
security/selinux/ima.c | 6 ++--
8 files changed, 39 insertions(+), 19 deletions(-)
diff --git a/include/linux/ima.h b/include/linux/ima.h
index 60492263aa64..b6ab66a546ae 100644
--- a/include/linux/ima.h
+++ b/include/linux/ima.h
@@ -38,7 +38,7 @@ extern void ima_kexec_cmdline(int kernel_fd, const void *buf, int size);
extern int ima_measure_critical_data(const char *event_label,
const char *event_name,
const void *buf, size_t buf_len,
- bool hash);
+ bool hash, u8 *digest, size_t digest_len);
#ifdef CONFIG_IMA_APPRAISE_BOOTPARAM
extern void ima_appraise_parse_cmdline(void);
@@ -147,7 +147,8 @@ static inline void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) {
static inline int ima_measure_critical_data(const char *event_label,
const char *event_name,
const void *buf, size_t buf_len,
- bool hash)
+ bool hash, u8 *digest,
+ size_t digest_len)
{
return -ENOENT;
}
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 03db221324c3..2f4c20b16ad7 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -268,7 +268,7 @@ int process_buffer_measurement(struct user_namespace *mnt_userns,
struct inode *inode, const void *buf, int size,
const char *eventname, enum ima_hooks func,
int pcr, const char *func_data,
- bool buf_hash);
+ bool buf_hash, u8 *digest, size_t digest_len);
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 ef9dcfce45d4..63bec42c353f 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -357,7 +357,7 @@ int ima_check_blacklist(struct integrity_iint_cache *iint,
if ((rc == -EPERM) && (iint->flags & IMA_MEASURE))
process_buffer_measurement(&init_user_ns, NULL, digest, digestsize,
"blacklisted-hash", NONE,
- pcr, NULL, false);
+ pcr, NULL, false, NULL, 0);
}
return rc;
diff --git a/security/integrity/ima/ima_asymmetric_keys.c b/security/integrity/ima/ima_asymmetric_keys.c
index c985418698a4..f6aa0b47a772 100644
--- a/security/integrity/ima/ima_asymmetric_keys.c
+++ b/security/integrity/ima/ima_asymmetric_keys.c
@@ -62,5 +62,5 @@ void ima_post_key_create_or_update(struct key *keyring, struct key *key,
*/
process_buffer_measurement(&init_user_ns, NULL, payload, payload_len,
keyring->description, KEY_CHECK, 0,
- keyring->description, false);
+ keyring->description, false, NULL, 0);
}
diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c
index 5076a7d9d23e..b26fa67476b4 100644
--- a/security/integrity/ima/ima_init.c
+++ b/security/integrity/ima/ima_init.c
@@ -154,7 +154,8 @@ int __init ima_init(void)
ima_init_key_queue();
ima_measure_critical_data("kernel_info", "kernel_version",
- UTS_RELEASE, strlen(UTS_RELEASE), false);
+ UTS_RELEASE, strlen(UTS_RELEASE), false,
+ NULL, 0);
return rc;
}
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index b512c06d8ee1..360266da5a10 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -838,17 +838,20 @@ int ima_post_load_data(char *buf, loff_t size,
* @pcr: pcr to extend the measurement
* @func_data: func specific data, may be NULL
* @buf_hash: measure buffer data hash
+ * @digest: buffer digest will be written to
+ * @digest_len: buffer length
*
* Based on policy, either the buffer data or buffer data hash is measured
*
- * Return: 0 if the buffer has been successfully measured, a negative value
- * otherwise.
+ * Return: 0 if the buffer has been successfully measured, 1 if the digest
+ * has been written to the passed location but not added to a measurement entry,
+ * a negative value otherwise.
*/
int process_buffer_measurement(struct user_namespace *mnt_userns,
struct inode *inode, const void *buf, int size,
const char *eventname, enum ima_hooks func,
int pcr, const char *func_data,
- bool buf_hash)
+ bool buf_hash, u8 *digest, size_t digest_len)
{
int ret = 0;
const char *audit_cause = "ENOMEM";
@@ -869,7 +872,10 @@ int process_buffer_measurement(struct user_namespace *mnt_userns,
int action = 0;
u32 secid;
- if (!ima_policy_flag)
+ if (digest && digest_len < digest_hash_len)
+ return -EINVAL;
+
+ if (!ima_policy_flag && !digest)
return -ENOENT;
template = ima_template_desc_buf();
@@ -891,7 +897,7 @@ int process_buffer_measurement(struct user_namespace *mnt_userns,
action = ima_get_action(mnt_userns, inode, current_cred(),
secid, 0, func, &pcr, &template,
func_data);
- if (!(action & IMA_MEASURE))
+ if (!(action & IMA_MEASURE) && !digest)
return -ENOENT;
}
@@ -922,6 +928,12 @@ int process_buffer_measurement(struct user_namespace *mnt_userns,
event_data.buf_len = digest_hash_len;
}
+ if (digest)
+ memcpy(digest, iint.ima_hash->digest, digest_hash_len);
+
+ if (!ima_policy_flag || (func && !(action & IMA_MEASURE)))
+ return 1;
+
ret = ima_alloc_init_template(&event_data, &entry, template);
if (ret < 0) {
audit_cause = "alloc_entry";
@@ -964,7 +976,7 @@ void ima_kexec_cmdline(int kernel_fd, const void *buf, int size)
process_buffer_measurement(file_mnt_user_ns(f.file), file_inode(f.file),
buf, size, "kexec-cmdline", KEXEC_CMDLINE, 0,
- NULL, false);
+ NULL, false, NULL, 0);
fdput(f);
}
@@ -975,26 +987,30 @@ void ima_kexec_cmdline(int kernel_fd, const void *buf, int size)
* @buf: pointer to buffer data
* @buf_len: length of buffer data (in bytes)
* @hash: measure buffer data hash
+ * @digest: buffer digest will be written to
+ * @digest_len: buffer length
*
* Measure data critical to the integrity of the kernel into the IMA log
* and extend the pcr. Examples of critical data could be various data
* structures, policies, and states stored in kernel memory that can
* impact the integrity of the system.
*
- * Return: 0 if the buffer has been successfully measured, a negative value
- * otherwise.
+ * Return: 0 if the buffer has been successfully measured, 1 if the digest
+ * has been written to the passed location but not added to a measurement entry,
+ * a negative value otherwise.
*/
int ima_measure_critical_data(const char *event_label,
const char *event_name,
const void *buf, size_t buf_len,
- bool hash)
+ bool hash, u8 *digest, size_t digest_len)
{
if (!event_name || !event_label || !buf || !buf_len)
return -ENOPARAM;
return process_buffer_measurement(&init_user_ns, NULL, buf, buf_len,
event_name, CRITICAL_DATA, 0,
- event_label, hash);
+ event_label, hash, digest,
+ digest_len);
}
static int __init init_ima(void)
diff --git a/security/integrity/ima/ima_queue_keys.c b/security/integrity/ima/ima_queue_keys.c
index 979ef6c71f3d..93056c03bf5a 100644
--- a/security/integrity/ima/ima_queue_keys.c
+++ b/security/integrity/ima/ima_queue_keys.c
@@ -165,7 +165,7 @@ void ima_process_queued_keys(void)
entry->keyring_name,
KEY_CHECK, 0,
entry->keyring_name,
- false);
+ false, NULL, 0);
list_del(&entry->list);
ima_free_key_entry(entry);
}
diff --git a/security/selinux/ima.c b/security/selinux/ima.c
index 34d421861bfc..727c4e43219d 100644
--- a/security/selinux/ima.c
+++ b/security/selinux/ima.c
@@ -86,7 +86,8 @@ void selinux_ima_measure_state_locked(struct selinux_state *state)
}
ima_measure_critical_data("selinux", "selinux-state",
- state_str, strlen(state_str), false);
+ state_str, strlen(state_str), false,
+ NULL, 0);
kfree(state_str);
@@ -103,7 +104,8 @@ void selinux_ima_measure_state_locked(struct selinux_state *state)
}
ima_measure_critical_data("selinux", "selinux-policy-hash",
- policy, policy_len, true);
+ policy, policy_len, true,
+ NULL, 0);
vfree(policy);
}
--
2.25.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v4 1/3] ima: Introduce ima_get_current_hash_algo()
2021-07-23 8:53 ` [PATCH v4 1/3] ima: Introduce ima_get_current_hash_algo() Roberto Sassu
@ 2021-07-23 12:49 ` Mimi Zohar
2021-07-23 12:51 ` Roberto Sassu
0 siblings, 1 reply; 6+ messages in thread
From: Mimi Zohar @ 2021-07-23 12:49 UTC (permalink / raw)
To: Roberto Sassu, paul
Cc: stephen.smalley.work, prsriva02, tusharsu, nramas,
linux-integrity, linux-security-module, linux-kernel, selinux
On Fri, 2021-07-23 at 10:53 +0200, Roberto Sassu wrote:
> Buffer measurements, unlike file measurements, are not accessible after the
> measurement is done, as buffers are not suitable for use with the
> integrity_iint_cache structure (there is no index, for files it is the
> inode number). In the subsequent patches, the measurement (digest) will be
> returned directly by the functions that perform the buffer measurement,
> ima_measure_critical_data() and process_buffer_measurement().
>
> A caller of those functions also needs to know the algorithm used to
> calculate the digest. Instead of adding the algorithm as a new parameter to
> the functions, this patch provides it separately with the new function
> ima_get_current_hash_algo().
>
> Since the hash algorithm does not change after the IMA setup phase, there
> is no risk of races (obtaining a digest calculated with a different
> algorithm than the one returned).
Perfect explaination for annotating ima_hash_algo like:
int __ro_after_init ima_hash_algo = HASH_ALGO_SHA1;
Assuming you don't object, I'll include this change in this patch.
thanks,
Mimi
>
> Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
> Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
^ permalink raw reply [flat|nested] 6+ messages in thread
* RE: [PATCH v4 1/3] ima: Introduce ima_get_current_hash_algo()
2021-07-23 12:49 ` Mimi Zohar
@ 2021-07-23 12:51 ` Roberto Sassu
0 siblings, 0 replies; 6+ messages in thread
From: Roberto Sassu @ 2021-07-23 12:51 UTC (permalink / raw)
To: Mimi Zohar, paul
Cc: stephen.smalley.work, prsriva02, tusharsu, nramas,
linux-integrity, linux-security-module, linux-kernel, selinux
> From: Mimi Zohar [mailto:zohar@linux.ibm.com]
> Sent: Friday, July 23, 2021 2:49 PM
> On Fri, 2021-07-23 at 10:53 +0200, Roberto Sassu wrote:
> > Buffer measurements, unlike file measurements, are not accessible after the
> > measurement is done, as buffers are not suitable for use with the
> > integrity_iint_cache structure (there is no index, for files it is the
> > inode number). In the subsequent patches, the measurement (digest) will be
> > returned directly by the functions that perform the buffer measurement,
> > ima_measure_critical_data() and process_buffer_measurement().
> >
> > A caller of those functions also needs to know the algorithm used to
> > calculate the digest. Instead of adding the algorithm as a new parameter to
> > the functions, this patch provides it separately with the new function
> > ima_get_current_hash_algo().
> >
> > Since the hash algorithm does not change after the IMA setup phase, there
> > is no risk of races (obtaining a digest calculated with a different
> > algorithm than the one returned).
>
> Perfect explaination for annotating ima_hash_algo like:
>
> int __ro_after_init ima_hash_algo = HASH_ALGO_SHA1;
>
> Assuming you don't object, I'll include this change in this patch.
Sure, thanks.
Roberto
HUAWEI TECHNOLOGIES Duesseldorf GmbH, HRB 56063
Managing Director: Li Peng, Li Jian, Shi Yanli
> thanks,
>
> Mimi
>
> >
> > Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
> > Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2021-07-23 12:51 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-07-23 8:53 [PATCH v4 0/3] ima: Provide more info about buffer measurement Roberto Sassu
2021-07-23 8:53 ` [PATCH v4 1/3] ima: Introduce ima_get_current_hash_algo() Roberto Sassu
2021-07-23 12:49 ` Mimi Zohar
2021-07-23 12:51 ` Roberto Sassu
2021-07-23 8:53 ` [PATCH v4 2/3] ima: Return int in the functions to measure a buffer Roberto Sassu
2021-07-23 8:53 ` [PATCH v4 3/3] ima: Add digest and digest_len params to " Roberto Sassu
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