[v37,01/33] integrity: disassociate ima_filter_rule from security_audit_rule

Commit Message

Casey Schaufler June 28, 2022, 12:55 a.m. UTC

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

Acked-by: Paul Moore <[e-mail]>
Reviewed-by: John Johansen <[e-mail]>
Signed-off-by: Casey Schaufler <[e-mail]>
To: Mimi Zohar <[e-mail]>
Cc: [e-mail]
---
 include/linux/security.h     | 24 ++++++++++++++++++++++++
 security/integrity/ima/ima.h | 26 --------------------------
 security/security.c          | 21 +++++++++++++++++++++
 3 files changed, 45 insertions(+), 26 deletions(-)

Patch

diff --git a/include/linux/security.h b/include/linux/security.h
index 7fc4e9f49f54..5260dbe9ef0d 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1919,6 +1919,30 @@  static inline void security_audit_rule_free(void *lsmrule)
 #endif /* CONFIG_SECURITY */
 #endif /* CONFIG_AUDIT */
 
+#if defined(CONFIG_IMA_LSM_RULES) && defined(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 /* defined(CONFIG_IMA_LSM_RULES) && defined(CONFIG_SECURITY) */
+
 #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 188b8f782220..8b176769dd86 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2580,6 +2580,27 @@  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)
 {