[PATCH v33 01/29] integrity: disassociate ima_filter_rule from security_audit_rule

Casey Schaufler
2022-03-10T23:46:58Z

Create real functions for the ima_filter_rule interfaces.
These replace #defines that obscure the reuse of audit
interfaces. The new fuctions are put in security.c because
they use security module registered hooks that we don't
want exported.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Paul Moore <paul@paul-moore.com>
---
include/linux/security.h | 26 ++++++++++++++++++++++++++
security/integrity/ima/ima.h | 26 --------------------------
security/security.c | 21 +++++++++++++++++++++
3 files changed, 47 insertions(+), 26 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index 6d72772182c8..33e0f2e659df 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1909,6 +1909,32 @@ static inline void security_audit_rule_free(void *lsmrule)
#endif /* CONFIG_SECURITY */
#endif /* CONFIG_AUDIT */

+#ifdef CONFIG_IMA_LSM_RULES
+#ifdef CONFIG_SECURITY
+int ima_filter_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule);
+int ima_filter_rule_match(u32 secid, u32 field, u32 op, void *lsmrule);
+void ima_filter_rule_free(void *lsmrule);
+
+#else
+
+static inline int ima_filter_rule_init(u32 field, u32 op, char *rulestr,
+ void **lsmrule)
+{
+ return 0;
+}
+
+static inline int ima_filter_rule_match(u32 secid, u32 field, u32 op,
+ void *lsmrule)
+{
+ return 0;
+}
+
+static inline void ima_filter_rule_free(void *lsmrule)
+{ }
+
+#endif /* CONFIG_SECURITY */
+#endif /* CONFIG_IMA_LSM_RULES */
+
#ifdef CONFIG_SECURITYFS

extern struct dentry *securityfs_create_file(const char *name, umode_t mode,
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index be965a8715e4..1b5d70ac2dc9 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -418,32 +418,6 @@ static inline void ima_free_modsig(struct modsig *modsig)
}
#endif /* CONFIG_IMA_APPRAISE_MODSIG */

-/* LSM based policy rules require audit */
-#ifdef CONFIG_IMA_LSM_RULES
-
-#define ima_filter_rule_init security_audit_rule_init
-#define ima_filter_rule_free security_audit_rule_free
-#define ima_filter_rule_match security_audit_rule_match
-
-#else
-
-static inline int ima_filter_rule_init(u32 field, u32 op, char *rulestr,
- void **lsmrule)
-{
- return -EINVAL;
-}
-
-static inline void ima_filter_rule_free(void *lsmrule)
-{
-}
-
-static inline int ima_filter_rule_match(u32 secid, u32 field, u32 op,
- void *lsmrule)
-{
- return -EINVAL;
-}
-#endif /* CONFIG_IMA_LSM_RULES */
-
#ifdef CONFIG_IMA_READ_POLICY
#define POLICY_FILE_FLAGS (S_IWUSR | S_IRUSR)
#else
diff --git a/security/security.c b/security/security.c
index 22261d79f333..5208b21c8433 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2566,6 +2566,27 @@ int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule)
}
#endif /* CONFIG_AUDIT */

+#ifdef CONFIG_IMA_LSM_RULES
+/*
+ * The integrity subsystem uses the same hooks as
+ * the audit subsystem.
+ */
+int ima_filter_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule)
+{
+ return call_int_hook(audit_rule_init, 0, field, op, rulestr, lsmrule);
+}
+
+void ima_filter_rule_free(void *lsmrule)
+{
+ call_void_hook(audit_rule_free, lsmrule);
+}
+
+int ima_filter_rule_match(u32 secid, u32 field, u32 op, void *lsmrule)
+{
+ return call_int_hook(audit_rule_match, 0, secid, field, op, lsmrule);
+}
+#endif /* CONFIG_IMA_LSM_RULES */
+
#ifdef CONFIG_BPF_SYSCALL
int security_bpf(int cmd, union bpf_attr *attr, unsigned int size)
{
--
2.31.1