apparmor: refactor code that alloc null profiles

Bother unconfined and learning profiles use the null profile as their
base. Refactor so they are share a common base routine. This doesn't
save much atm but will be important when the feature set of the
parent is inherited.
Signed-off-by: John Johansen <john.johansen@canonical.com>

security/apparmor/domain.c

@@ -681,8 +681,8 @@ static struct aa_label *profile_transition(struct aa_profile *profile,
 		/* no exec permission - learning mode */
 		struct aa_profile *new_profile = NULL;
 
-		new_profile = aa_new_null_profile(profile, false, name,
-						  GFP_KERNEL);
+		new_profile = aa_new_learning_profile(profile, false, name,
+						      GFP_KERNEL);
 		if (!new_profile) {
 			error = -ENOMEM;
 			info = "could not create null profile";
@@ -1009,8 +1009,8 @@ static struct aa_label *build_change_hat(struct aa_profile *profile,
 	if (!hat) {
 		error = -ENOENT;
 		if (COMPLAIN_MODE(profile)) {
-			hat = aa_new_null_profile(profile, true, name,
-						  GFP_KERNEL);
+			hat = aa_new_learning_profile(profile, true, name,
+						      GFP_KERNEL);
 			if (!hat) {
 				info = "failed null profile create";
 				error = -ENOMEM;
@@ -1361,8 +1361,8 @@ int aa_change_profile(const char *fqname, int flags)
 		    !COMPLAIN_MODE(labels_profile(label)))
 			goto audit;
 		/* released below */
-		tprofile = aa_new_null_profile(labels_profile(label), false,
-					       fqname, GFP_KERNEL);
+		tprofile = aa_new_learning_profile(labels_profile(label), false,
+						   fqname, GFP_KERNEL);
 		if (!tprofile) {
 			info = "failed null profile create";
 			error = -ENOMEM;

security/apparmor/include/policy.h

@@ -234,8 +234,10 @@ void aa_free_proxy_kref(struct kref *kref);
 struct aa_ruleset *aa_alloc_ruleset(gfp_t gfp);
 struct aa_profile *aa_alloc_profile(const char *name, struct aa_proxy *proxy,
 				    gfp_t gfp);
-struct aa_profile *aa_new_null_profile(struct aa_profile *parent, bool hat,
-				       const char *base, gfp_t gfp);
+struct aa_profile *aa_alloc_null(struct aa_profile *parent, const char *name,
+				 gfp_t gfp);
+struct aa_profile *aa_new_learning_profile(struct aa_profile *parent, bool hat,
+					   const char *base, gfp_t gfp);
 void aa_free_profile(struct aa_profile *profile);
 void aa_free_profile_kref(struct kref *kref);
 struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name);

security/apparmor/policy.c

@@ -524,8 +524,36 @@ struct aa_profile *aa_fqlookupn_profile(struct aa_label *base,
 	return profile;
 }
 
+
+struct aa_profile *aa_alloc_null(struct aa_profile *parent, const char *name,
+				 gfp_t gfp)
+{
+	struct aa_profile *profile;
+	struct aa_ruleset *rules;
+
+	profile = aa_alloc_profile(name, NULL, gfp);
+	if (!profile)
+		return NULL;
+
+	/* TODO: ideally we should inherit abi from parent */
+	profile->label.flags |= FLAG_NULL;
+	rules = list_first_entry(&profile->rules, typeof(*rules), list);
+	rules->file.dfa = aa_get_dfa(nulldfa);
+	rules->policy.dfa = aa_get_dfa(nulldfa);
+
+	if (parent) {
+		profile->path_flags = parent->path_flags;
+
+		/* released on free_profile */
+		rcu_assign_pointer(profile->parent, aa_get_profile(parent));
+		profile->ns = aa_get_ns(parent->ns);
+	}
+
+	return profile;
+}
+
 /**
- * aa_new_null_profile - create or find a null-X learning profile
+ * aa_new_learning_profile - create or find a null-X learning profile
  * @parent: profile that caused this profile to be created (NOT NULL)
  * @hat: true if the null- learning profile is a hat
  * @base: name to base the null profile off of
@@ -542,10 +570,9 @@ struct aa_profile *aa_fqlookupn_profile(struct aa_label *base,
  *
  * Returns: new refcounted profile else NULL on failure
  */
-struct aa_profile *aa_new_null_profile(struct aa_profile *parent, bool hat,
-				       const char *base, gfp_t gfp)
+struct aa_profile *aa_new_learning_profile(struct aa_profile *parent, bool hat,
+					   const char *base, gfp_t gfp)
 {
-	struct aa_ruleset *rules;
 	struct aa_profile *p, *profile;
 	const char *bname;
 	char *name = NULL;
@@ -575,22 +602,12 @@ struct aa_profile *aa_new_null_profile(struct aa_profile *parent, bool hat,
 	if (profile)
 		goto out;
 
-	profile = aa_alloc_profile(name, NULL, gfp);
+	profile = aa_alloc_null(parent, name, gfp);
 	if (!profile)
 		goto fail;
-
 	profile->mode = APPARMOR_COMPLAIN;
-	profile->label.flags |= FLAG_NULL;
 	if (hat)
 		profile->label.flags |= FLAG_HAT;
-	profile->path_flags = parent->path_flags;
-
-	/* released on free_profile */
-	rcu_assign_pointer(profile->parent, aa_get_profile(parent));
-	profile->ns = aa_get_ns(parent->ns);
-	rules = list_first_entry(&profile->rules, typeof(*rules), list);
-	rules->file.dfa = aa_get_dfa(nulldfa);
-	rules->policy.dfa = aa_get_dfa(nulldfa);
 
 	mutex_lock_nested(&profile->ns->lock, profile->ns->level);
 	p = __find_child(&parent->base.profiles, bname);

security/apparmor/policy_ns.c

@@ -83,18 +83,14 @@ const char *aa_ns_name(struct aa_ns *curr, struct aa_ns *view, bool subns)
 static struct aa_profile *alloc_unconfined(const char *name)
 {
 	struct aa_profile *profile;
-	struct aa_ruleset *rules;
 
-	profile = aa_alloc_profile(name, NULL, GFP_KERNEL);
+	profile = aa_alloc_null(NULL, name, GFP_KERNEL);
 	if (!profile)
 		return NULL;
 
 	profile->label.flags |= FLAG_IX_ON_NAME_ERROR |
 		FLAG_IMMUTIBLE | FLAG_NS_COUNT | FLAG_UNCONFINED;
 	profile->mode = APPARMOR_UNCONFINED;
-	rules = list_first_entry(&profile->rules, typeof(*rules), list);
-	rules->file.dfa = aa_get_dfa(nulldfa);
-	rules->policy.dfa = aa_get_dfa(nulldfa);
 
 	return profile;
 }