[PATCH v9 11/23] ima: Move ima_lsm_policy_notifier into ima_namespace

[Stefan Berger]

From: Stefan Berger <stefanb@xxxxxxxxxxxxx>

Move the ima_lsm_policy_notifier into the ima_namespace. Each IMA
namespace can now register its own LSM policy change notifier callback.
The policy change notifier for the init_ima_ns still remains in init_ima()
and therefore handle the registration of the callback for all other
namespaces in init_ima_namespace().

Signed-off-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>
---
 security/integrity/ima/ima.h             |  2 ++
 security/integrity/ima/ima_init_ima_ns.c | 14 ++++++++++++++
 security/integrity/ima/ima_main.c        |  6 +-----
 security/integrity/ima/ima_policy.c      |  4 +++-
 4 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 94c6e3a4d666..fb6bd054d899 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -144,6 +144,8 @@ struct ima_namespace {
 	int valid_policy;
 
 	struct dentry *ima_policy;
+
+	struct notifier_block ima_lsm_policy_notifier;
 } __randomize_layout;
 extern struct ima_namespace init_ima_ns;
 
diff --git a/security/integrity/ima/ima_init_ima_ns.c b/security/integrity/ima/ima_init_ima_ns.c
index 425eed1c6838..1cba545ae477 100644
--- a/security/integrity/ima/ima_init_ima_ns.c
+++ b/security/integrity/ima/ima_init_ima_ns.c
@@ -10,6 +10,8 @@
 
 static int ima_init_namespace(struct ima_namespace *ns)
 {
+	int rc;
+
 	INIT_LIST_HEAD(&ns->ima_default_rules);
 	INIT_LIST_HEAD(&ns->ima_policy_rules);
 	INIT_LIST_HEAD(&ns->ima_temp_rules);
@@ -30,6 +32,15 @@ static int ima_init_namespace(struct ima_namespace *ns)
 	ns->valid_policy = 1;
 	ns->ima_fs_flags = 0;
 
+	if (ns != &init_ima_ns) {
+		ns->ima_lsm_policy_notifier.notifier_call =
+						ima_lsm_policy_change;
+		rc = register_blocking_lsm_notifier
+						(&ns->ima_lsm_policy_notifier);
+		if (rc)
+			return rc;
+	}
+
 	return 0;
 }
 
@@ -39,5 +50,8 @@ int __init ima_ns_init(void)
 }
 
 struct ima_namespace init_ima_ns = {
+	.ima_lsm_policy_notifier = {
+		.notifier_call = ima_lsm_policy_change,
+	},
 };
 EXPORT_SYMBOL(init_ima_ns);
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 2cd5cc90ab79..ae0e9b14554a 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -38,10 +38,6 @@ int ima_appraise;
 int __ro_after_init ima_hash_algo = HASH_ALGO_SHA1;
 static int hash_setup_done;
 
-static struct notifier_block ima_lsm_policy_notifier = {
-	.notifier_call = ima_lsm_policy_change,
-};
-
 static int __init hash_setup(char *str)
 {
 	struct ima_template_desc *template_desc = ima_template_desc_current();
@@ -1072,7 +1068,7 @@ static int __init init_ima(void)
 	if (error)
 		return error;
 
-	error = register_blocking_lsm_notifier(&ima_lsm_policy_notifier);
+	error = register_blocking_lsm_notifier(&ns->ima_lsm_policy_notifier);
 	if (error)
 		pr_warn("Couldn't register LSM notifier, error %d\n", error);
 
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 05b2bc06ab0c..3b754b9f5ef7 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -465,12 +465,14 @@ static void ima_lsm_update_rules(struct ima_namespace *ns)
 int ima_lsm_policy_change(struct notifier_block *nb, unsigned long event,
 			  void *lsm_data)
 {
-	struct ima_namespace *ns = &init_ima_ns;
+	struct ima_namespace *ns;
 
 	if (event != LSM_POLICY_CHANGE)
 		return NOTIFY_DONE;
 
+	ns = container_of(nb, struct ima_namespace, ima_lsm_policy_notifier);
 	ima_lsm_update_rules(ns);
+
 	return NOTIFY_OK;
 }
 
-- 
2.31.1