[PATCH] ima: Rename internal audit rule functions

From: Tyler Hicks
Date: Mon Jun 29 2020 - 15:10:09 EST


Rename IMA's internal audit rule functions from security_filter_rule_*()
to ima_audit_rule_*(). This avoids polluting the security_* namespace,
which is typically reserved for general security subsystem
infrastructure, and better aligns the IMA function names with the names
of the LSM hooks.

Signed-off-by: Tyler Hicks <tyhicks@xxxxxxxxxxxxxxxxxxx>
Suggested-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
---

Developed on top of next-integrity-testing, commit cd1d8603df60 ("IMA:
Add audit log for failure conditions"), plus this patch series:

[PATCH v2 00/11] ima: Fix rule parsing bugs and extend KEXEC_CMDLINE rule support
https://lore.kernel.org/linux-integrity/20200626223900.253615-1-tyhicks@xxxxxxxxxxxxxxxxxxx/T/#t

This patch has dependencies on the above patch series.

Tested with and without CONFIG_IMA_LSM_RULES enabled by attempting to
load IMA policy with rules containing the subj_role=foo conditional.
Build logs are clean in both configurations. The IMA policy was first
loaded without and then with a valid AppArmor profile named "foo". The
behavior is the same before and after this patch is applied:

| CONFIG_IMA_LSM_RULES=n | CONFIG_IMA_LSM_RULES=y
-----------------------------------------------------------------------
Without Profile | IMA policy load fails | IMA policy load fails
With Profile | IMA policy load fails | IMA policy load succeeds

security/integrity/ima/ima.h | 16 +++++++--------
security/integrity/ima/ima_policy.c | 30 +++++++++++++----------------
2 files changed, 21 insertions(+), 25 deletions(-)

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index ff2bf57ff0c7..5d62ee8319f4 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -419,24 +419,24 @@ static inline void ima_free_modsig(struct modsig *modsig)
/* LSM based policy rules require audit */
#ifdef CONFIG_IMA_LSM_RULES

-#define security_filter_rule_init security_audit_rule_init
-#define security_filter_rule_free security_audit_rule_free
-#define security_filter_rule_match security_audit_rule_match
+#define ima_audit_rule_init security_audit_rule_init
+#define ima_audit_rule_free security_audit_rule_free
+#define ima_audit_rule_match security_audit_rule_match

#else

-static inline int security_filter_rule_init(u32 field, u32 op, char *rulestr,
- void **lsmrule)
+static inline int ima_audit_rule_init(u32 field, u32 op, char *rulestr,
+ void **lsmrule)
{
return -EINVAL;
}

-static inline void security_filter_rule_free(void *lsmrule)
+static inline void ima_audit_rule_free(void *lsmrule)
{
}

-static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
- void *lsmrule)
+static inline int ima_audit_rule_match(u32 secid, u32 field, u32 op,
+ void *lsmrule)
{
return -EINVAL;
}
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 294323b36d06..60894656a4b7 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -258,7 +258,7 @@ static void ima_lsm_free_rule(struct ima_rule_entry *entry)
int i;

for (i = 0; i < MAX_LSM_RULES; i++) {
- security_filter_rule_free(entry->lsm[i].rule);
+ ima_audit_rule_free(entry->lsm[i].rule);
kfree(entry->lsm[i].args_p);
}
}
@@ -308,10 +308,9 @@ static struct ima_rule_entry *ima_lsm_copy_rule(struct ima_rule_entry *entry)
*/
entry->lsm[i].args_p = NULL;

- security_filter_rule_init(nentry->lsm[i].type,
- Audit_equal,
- nentry->lsm[i].args_p,
- &nentry->lsm[i].rule);
+ ima_audit_rule_init(nentry->lsm[i].type, Audit_equal,
+ nentry->lsm[i].args_p,
+ &nentry->lsm[i].rule);
if (!nentry->lsm[i].rule)
pr_warn("rule for LSM \'%s\' is undefined\n",
entry->lsm[i].args_p);
@@ -495,18 +494,16 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
case LSM_OBJ_ROLE:
case LSM_OBJ_TYPE:
security_inode_getsecid(inode, &osid);
- rc = security_filter_rule_match(osid,
- rule->lsm[i].type,
- Audit_equal,
- rule->lsm[i].rule);
+ rc = ima_audit_rule_match(osid, rule->lsm[i].type,
+ Audit_equal,
+ rule->lsm[i].rule);
break;
case LSM_SUBJ_USER:
case LSM_SUBJ_ROLE:
case LSM_SUBJ_TYPE:
- rc = security_filter_rule_match(secid,
- rule->lsm[i].type,
- Audit_equal,
- rule->lsm[i].rule);
+ rc = ima_audit_rule_match(secid, rule->lsm[i].type,
+ Audit_equal,
+ rule->lsm[i].rule);
default:
break;
}
@@ -901,10 +898,9 @@ static int ima_lsm_rule_init(struct ima_rule_entry *entry,
return -ENOMEM;

entry->lsm[lsm_rule].type = audit_type;
- result = security_filter_rule_init(entry->lsm[lsm_rule].type,
- Audit_equal,
- entry->lsm[lsm_rule].args_p,
- &entry->lsm[lsm_rule].rule);
+ result = ima_audit_rule_init(entry->lsm[lsm_rule].type, Audit_equal,
+ entry->lsm[lsm_rule].args_p,
+ &entry->lsm[lsm_rule].rule);
if (!entry->lsm[lsm_rule].rule) {
pr_warn("rule for LSM \'%s\' is undefined\n",
entry->lsm[lsm_rule].args_p);
--
2.25.1