Admins may wish to log different measurements using different IMA
templates. Add support for overriding the default template on a per-rule
basis.
Signed-off-by: Matthew Garrett <mjg59@xxxxxxxxxx>
---
Updated based on review feedback, verified that I can generate an event
log that contains multiple different templates.
Documentation/ABI/testing/ima_policy | 6 ++++--
security/integrity/ima/ima.h | 13 +++++++++----
security/integrity/ima/ima_api.c | 24 ++++++++++++++++-------
security/integrity/ima/ima_appraise.c | 2 +-
security/integrity/ima/ima_init.c | 2 +-
security/integrity/ima/ima_main.c | 9 +++++----
security/integrity/ima/ima_policy.c | 28 +++++++++++++++++++++++++--
security/integrity/ima/ima_template.c | 10 ++++++++--
8 files changed, 71 insertions(+), 23 deletions(-)
diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy
index 74c6702de74e..4ded0668a22d 100644
--- a/Documentation/ABI/testing/ima_policy
+++ b/Documentation/ABI/testing/ima_policy
@@ -24,8 +24,7 @@ Description:
[euid=] [fowner=] [fsname=]]
lsm: [[subj_user=] [subj_role=] [subj_type=]
[obj_user=] [obj_role=] [obj_type=]]
- option: [[appraise_type=]] [permit_directio]
-
+ option: [[appraise_type=]] [template=] [permit_directio]
base: func:= [BPRM_CHECK][MMAP_CHECK][CREDS_CHECK][FILE_CHECK][MODULE_CHECK]
[FIRMWARE_CHECK]
[KEXEC_KERNEL_CHECK] [KEXEC_INITRAMFS_CHECK]
@@ -38,6 +37,9 @@ Description:
fowner:= decimal value
lsm: are LSM specific
option: appraise_type:= [imasig]
+ template:= name or format of a defined IMA template
+ type (eg,ima-ng or d-ng|n-ng). Only valid when action
+ is "measure".
pcr:= decimal value
default policy:
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index d213e835c498..18b48a6d0b80 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -147,6 +147,7 @@ int ima_init_crypto(void);
void ima_putc(struct seq_file *m, void *data, int datalen);
void ima_print_digest(struct seq_file *m, u8 *digest, u32 size);
struct ima_template_desc *ima_template_desc_current(void);
+struct ima_template_desc *lookup_template_desc(const char *name);
int ima_restore_measurement_entry(struct ima_template_entry *entry);
int ima_restore_measurement_list(loff_t bufsize, void *buf);
int ima_measurements_show(struct seq_file *m, void *v);
@@ -193,7 +194,8 @@ enum ima_hooks {
/* LIM API function definitions */
int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
- int mask, enum ima_hooks func, int *pcr);
+ int mask, enum ima_hooks func, int *pcr,
+ struct ima_template_desc **template_desc);
int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func);
int ima_collect_measurement(struct integrity_iint_cache *iint,
struct file *file, void *buf, loff_t size,
@@ -201,11 +203,13 @@ int ima_collect_measurement(struct integrity_iint_cache *iint,
void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
const unsigned char *filename,
struct evm_ima_xattr_data *xattr_value,
- int xattr_len, int pcr);
+ int xattr_len, int pcr,
+ struct ima_template_desc *template_desc);
void ima_audit_measurement(struct integrity_iint_cache *iint,
const unsigned char *filename);
int ima_alloc_init_template(struct ima_event_data *event_data,
- struct ima_template_entry **entry);
+ struct ima_template_entry **entry,
+ struct ima_template_desc *template_desc);
int ima_store_template(struct ima_template_entry *entry, int violation,
struct inode *inode,
const unsigned char *filename, int pcr);
@@ -214,7 +218,8 @@ const char *ima_d_path(const struct path *path, char **pathbuf, char *filename);
/* IMA policy related functions */
int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
- enum ima_hooks func, int mask, int flags, int *pcr);
+ enum ima_hooks func, int mask, int flags, int *pcr,
+ struct ima_template_desc **template_desc);
void ima_init_policy(void);
void ima_update_policy(void);
void ima_update_policy_flag(void);
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index c7505fb122d4..78eb11c7ac07 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -38,11 +38,17 @@ void ima_free_template_entry(struct ima_template_entry *entry)
* ima_alloc_init_template - create and initialize a new template entry
*/
int ima_alloc_init_template(struct ima_event_data *event_data,
- struct ima_template_entry **entry)
+ struct ima_template_entry **entry,
+ struct ima_template_desc *desc)
{
- struct ima_template_desc *template_desc = ima_template_desc_current();
+ struct ima_template_desc *template_desc;
int i, result = 0;
+ if (desc)
+ template_desc = desc;
+ else
+ template_desc = ima_template_desc_current();
+
*entry = kzalloc(sizeof(**entry) + template_desc->num_fields *
sizeof(struct ima_field_data), GFP_NOFS);
if (!*entry)
@@ -141,7 +147,7 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
/* can overflow, only indicator */
atomic_long_inc(&ima_htable.violations);
- result = ima_alloc_init_template(&event_data, &entry);
+ result = ima_alloc_init_template(&event_data, &entry, NULL);
if (result < 0) {
result = -ENOMEM;
goto err_out;
@@ -164,6 +170,7 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
* MAY_APPEND)
* @func: caller identifier
* @pcr: pointer filled in if matched measure policy sets pcr=
+ * @template_desc: pointer filled in if matched measure policy sets template=
*
* The policy is defined in terms of keypairs:
* subj=, obj=, type=, func=, mask=, fsmagic=
@@ -176,13 +183,15 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
*
*/
int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
- int mask, enum ima_hooks func, int *pcr)
+ int mask, enum ima_hooks func, int *pcr,
+ struct ima_template_desc **template_desc)
{
int flags = IMA_MEASURE | IMA_AUDIT | IMA_APPRAISE | IMA_HASH;
flags &= ima_policy_flag;
- return ima_match_policy(inode, cred, secid, func, mask, flags, pcr);
+ return ima_match_policy(inode, cred, secid, func, mask, flags, pcr,
+ template_desc);
}
/*
@@ -277,7 +286,8 @@ int ima_collect_measurement(struct integrity_iint_cache *iint,
void ima_store_measurement(struct integrity_iint_cache *iint,
struct file *file, const unsigned char *filename,
struct evm_ima_xattr_data *xattr_value,
- int xattr_len, int pcr)
+ int xattr_len, int pcr,
+ struct ima_template_desc *template_desc)
{
static const char op[] = "add_template_measure";
static const char audit_cause[] = "ENOMEM";
@@ -291,7 +301,7 @@ void ima_store_measurement(struct integrity_iint_cache *iint,
if (iint->measured_pcrs & (0x1 << pcr))
return;
- result = ima_alloc_init_template(&event_data, &entry);
+ result = ima_alloc_init_template(&event_data, &entry, template_desc);
if (result < 0) {
integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, filename,
op, audit_cause, result, 0);
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index 5fb7127bbe68..2f6536ab69e8 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -57,7 +57,7 @@ int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func)
security_task_getsecid(current, &secid);
return ima_match_policy(inode, current_cred(), secid, func, mask,
- IMA_APPRAISE | IMA_HASH, NULL);
+ IMA_APPRAISE | IMA_HASH, NULL, NULL);
}
static int ima_fix_xattr(struct dentry *dentry,
diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c
index 6c9295449751..993d0f1915ff 100644
--- a/security/integrity/ima/ima_init.c
+++ b/security/integrity/ima/ima_init.c
@@ -72,7 +72,7 @@ static int __init ima_add_boot_aggregate(void)
}
}
- result = ima_alloc_init_template(&event_data, &entry);
+ result = ima_alloc_init_template(&event_data, &entry, NULL);
if (result < 0) {
audit_cause = "alloc_entry";
goto err_out;
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 357edd140c09..83c5dea0d939 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -174,7 +174,7 @@ static int process_measurement(struct file *file, const struct cred *cred,
{
struct inode *inode = file_inode(file);
struct integrity_iint_cache *iint = NULL;
- struct ima_template_desc *template_desc;
+ struct ima_template_desc *template_desc = NULL;
char *pathbuf = NULL;
char filename[NAME_MAX];
const char *pathname = NULL;
@@ -192,7 +192,8 @@ static int process_measurement(struct file *file, const struct cred *cred,
* bitmask based on the appraise/audit/measurement policy.
* Included is the appraise submask.
*/
- action = ima_get_action(inode, cred, secid, mask, func, &pcr);
+ action = ima_get_action(inode, cred, secid, mask, func, &pcr,
+ &template_desc);
violation_check = ((func == FILE_CHECK || func == MMAP_CHECK) &&
(ima_policy_flag & IMA_MEASURE));
if (!action && !violation_check)
@@ -275,7 +276,6 @@ static int process_measurement(struct file *file, const struct cred *cred,
goto out_locked;
}
- template_desc = ima_template_desc_current();
if ((action & IMA_APPRAISE_SUBMASK) ||
strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) != 0)
/* read 'security.ima' */
@@ -292,7 +292,8 @@ static int process_measurement(struct file *file, const struct cred *cred,
if (action & IMA_MEASURE)
ima_store_measurement(iint, file, pathname,
- xattr_value, xattr_len, pcr);
+ xattr_value, xattr_len, pcr,
+ template_desc);
if (rc == 0 && (action & IMA_APPRAISE_SUBMASK)) {
inode_lock(inode);
rc = ima_appraise_measurement(func, iint, file, pathname,
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 0f6fe53cef09..cbae2a3a9c5b 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -80,6 +80,7 @@ struct ima_rule_entry {
int type; /* audit type */
} lsm[MAX_LSM_RULES];
char *fsname;
+ struct ima_template_desc *template;
};
/*
@@ -397,6 +398,7 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
* @func: IMA hook identifier
* @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
* @pcr: set the pcr to extend
+ * @template_desc: the template that should be used for this rule
*
* Measure decision based on func/mask/fsmagic and LSM(subj/obj/type)
* conditions.
@@ -406,7 +408,8 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
* than writes so ima_match_policy() is classical RCU candidate.
*/
int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
- enum ima_hooks func, int mask, int flags, int *pcr)
+ enum ima_hooks func, int mask, int flags, int *pcr,
+ struct ima_template_desc **template_desc)
{
struct ima_rule_entry *entry;
int action = 0, actmask = flags | (flags << 1);
@@ -438,6 +441,11 @@ int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
if ((pcr) && (entry->flags & IMA_PCR))
*pcr = entry->pcr;
+ if (template_desc && entry->template)
+ *template_desc = entry->template;
+ else
+ *template_desc = ima_template_desc_current();
+
if (!actmask)
break;
}
@@ -676,7 +684,7 @@ enum {
Opt_uid_gt, Opt_euid_gt, Opt_fowner_gt,
Opt_uid_lt, Opt_euid_lt, Opt_fowner_lt,
Opt_appraise_type, Opt_permit_directio,
- Opt_pcr, Opt_err
+ Opt_pcr, Opt_template, Opt_err
};
static const match_table_t policy_tokens = {
@@ -710,6 +718,7 @@ static const match_table_t policy_tokens = {
{Opt_appraise_type, "appraise_type=%s"},
{Opt_permit_directio, "permit_directio"},
{Opt_pcr, "pcr=%s"},
+ {Opt_template, "template=%s"},
{Opt_err, NULL}
};
@@ -763,6 +772,7 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
char *from;
char *p;
bool uid_token;
+ struct ima_template_desc *template_desc;
int result = 0;
ab = integrity_audit_log_start(audit_context(), GFP_KERNEL,
@@ -1059,6 +1069,18 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
entry->flags |= IMA_PCR;
break;
+ case Opt_template:
+ ima_log_string(ab, "template", args[0].from);
+ if (entry->action != MEASURE) {
+ result = -EINVAL;
+ break;
+ }
+ template_desc = lookup_template_desc(args[0].from);
+ if (!template_desc || entry->template)
+ result = -EINVAL;
+ else
+ entry->template = template_desc;
+ break;
case Opt_err:
ima_log_string(ab, "UNKNOWN", p);
result = -EINVAL;
@@ -1331,6 +1353,8 @@ int ima_policy_show(struct seq_file *m, void *v)
}
}
}
+ if (entry->template)
+ seq_printf(m, "template=%s ", entry->template->name);
if (entry->flags & IMA_DIGSIG_REQUIRED)
seq_puts(m, "appraise_type=imasig ");
if (entry->flags & IMA_PERMIT_DIRECTIO)
diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c
index b631b8bc7624..e6e892f31cbd 100644
--- a/security/integrity/ima/ima_template.c
+++ b/security/integrity/ima/ima_template.c
@@ -47,7 +47,6 @@ static const struct ima_template_field supported_fields[] = {
#define MAX_TEMPLATE_NAME_LEN 15
static struct ima_template_desc *ima_template;
-static struct ima_template_desc *lookup_template_desc(const char *name);
static int template_desc_init_fields(const char *template_fmt,
const struct ima_template_field ***fields,
int *num_fields);
@@ -108,7 +107,7 @@ static int __init ima_template_fmt_setup(char *str)
}
__setup("ima_template_fmt=", ima_template_fmt_setup);
-static struct ima_template_desc *lookup_template_desc(const char *name)
+struct ima_template_desc *lookup_template_desc(const char *name)
{
struct ima_template_desc *template_desc;
int found = 0;
@@ -117,6 +116,13 @@ static struct ima_template_desc *lookup_template_desc(const char *name)
list_for_each_entry_rcu(template_desc, &defined_templates, list) {
if ((strcmp(template_desc->name, name) == 0) ||
(strcmp(template_desc->fmt, name) == 0)) {
+ /*
+ * template_desc_init_fields() will return immediately
+ * if the template is already initialised
+ */
+ template_desc_init_fields(template_desc->fmt,
+ &(template_desc->fields),
+ &(template_desc->num_fields));
found = 1;
break;
}
--
2.22.0.rc1.311.g5d7573a151-goog
