security: remove dead hook key_session_to_parent

Unused hook.  Remove.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

security/capability.c

@@ -826,13 +826,6 @@ static int cap_key_getsecurity(struct key *key, char **_buffer)
 	return 0;
 }
 
-static int cap_key_session_to_parent(const struct cred *cred,
-				     const struct cred *parent_cred,
-				     struct key *key)
-{
-	return 0;
-}
-
 #endif /* CONFIG_KEYS */
 
 #ifdef CONFIG_AUDIT
@@ -1053,7 +1046,6 @@ void security_fixup_ops(struct security_operations *ops)
 	set_to_cap_if_null(ops, key_free);
 	set_to_cap_if_null(ops, key_permission);
 	set_to_cap_if_null(ops, key_getsecurity);
-	set_to_cap_if_null(ops, key_session_to_parent);
 #endif	/* CONFIG_KEYS */
 #ifdef CONFIG_AUDIT
 	set_to_cap_if_null(ops, audit_rule_init);

security/keys/keyctl.c

@@ -1295,13 +1295,6 @@ long keyctl_session_to_parent(void)
 	    mycred->tgcred->session_keyring->uid != mycred->euid)
 		goto not_permitted;
 
-	/* the LSM must permit the replacement of the parent's keyring with the
-	 * keyring from this process */
-	ret = security_key_session_to_parent(mycred, pcred,
-					     key_ref_to_ptr(keyring_r));
-	if (ret < 0)
-		goto not_permitted;
-
 	/* if there's an already pending keyring replacement, then we replace
 	 * that */
 	oldcred = parent->replacement_session_keyring;

security/security.c

@@ -1262,13 +1262,6 @@ int security_key_getsecurity(struct key *key, char **_buffer)
 	return security_ops->key_getsecurity(key, _buffer);
 }
 
-int security_key_session_to_parent(const struct cred *cred,
-				   const struct cred *parent_cred,
-				   struct key *key)
-{
-	return security_ops->key_session_to_parent(cred, parent_cred, key);
-}
-
 #endif	/* CONFIG_KEYS */
 
 #ifdef CONFIG_AUDIT