Add free function for sudo Python module.

This reduces the amount of memory leaked on unload.

plugins/python/python_convmessage.c

@@ -23,7 +23,7 @@
 
 #include "sudo_python_module.h"
 
-static PyTypeObject *sudo_type_ConvMessage;
+PyTypeObject *sudo_type_ConvMessage;
 
 static PyObject *
 _sudo_ConvMessage__Init(PyObject *py_self, PyObject *py_args, PyObject *py_kwargs)

plugins/python/python_loghandler.c

@@ -130,7 +130,7 @@ static PyMethodDef _sudo_LogHandler_class_methods[] =
 int
 sudo_module_set_default_loghandler()
 {
-    debug_decl(sudo_module_register_loghandler, PYTHON_DEBUG_INTERNAL);
+    debug_decl(sudo_module_set_default_loghandler, PYTHON_DEBUG_INTERNAL);
 
     PyObject *py_sudo, *py_logging_module = NULL, *py_logger = NULL,
 	     *py_streamhandler = NULL, *py_class = NULL,

plugins/python/python_plugin_common.c

@@ -64,7 +64,7 @@ _append_python_path(const char *module_dir)
 {
     debug_decl(_append_python_path, PYTHON_DEBUG_PLUGIN_LOAD);
     int rc = -1;
-    PyObject *py_sys_path = PySys_GetObject("path");
+    PyObject *py_sys_path = PySys_GetObject("path"); // borrowed
     if (py_sys_path == NULL) {
         PyErr_Format(sudo_exc_SudoException, "Failed to get python 'path'");
         debug_return_int(rc);
@@ -77,7 +77,7 @@ _append_python_path(const char *module_dir)
         Py_XDECREF(py_module_dir);
         debug_return_int(rc);
     }
-    Py_XDECREF(py_module_dir);
+    Py_DECREF(py_module_dir);
 
     if (sudo_debug_needed(SUDO_DEBUG_INFO)) {
         char *path = py_join_str_list(py_sys_path, ":");

plugins/python/sudo_python_module.c

@@ -42,6 +42,9 @@ static PyObject *python_sudo_conversation(PyObject *py_self, PyObject *py_args,
 static PyObject *python_sudo_options_as_dict(PyObject *py_self, PyObject *py_args);
 static PyObject *python_sudo_options_from_dict(PyObject *py_self, PyObject *py_args);
 
+// Called on module teardown.
+static void sudo_module_free(void *self);
+
 static PyMethodDef sudo_methods[] = {
     {"debug",  (PyCFunction)python_sudo_debug, METH_VARARGS, "Debug messages which can be saved to file in sudo.conf."},
     {"log_info",  (PyCFunction)python_sudo_log_info, METH_VARARGS | METH_KEYWORDS, "Display informational messages."},
@@ -62,7 +65,7 @@ static struct PyModuleDef sudo_module = {
     NULL, /* slots */
     NULL, /* traverse */
     NULL, /* clear */
-    NULL  /* free */
+    sudo_module_free
 };
 
 CPYCHECKER_NEGATIVE_RESULT_SETS_EXCEPTION
@@ -600,8 +603,29 @@ cleanup:
         Py_CLEAR(py_module);
         Py_CLEAR(sudo_exc_SudoException);
         Py_CLEAR(sudo_exc_PluginError);
+        Py_CLEAR(sudo_exc_PluginReject);
         Py_CLEAR(sudo_exc_ConversationInterrupted);
     }
 
     debug_return_ptr(py_module);
 }
+
+static void
+sudo_module_free(void *self)
+{
+    debug_decl(sudo_module_free, PYTHON_DEBUG_C_CALLS);
+
+    // Free exceptions
+    Py_CLEAR(sudo_exc_SudoException);
+    Py_CLEAR(sudo_exc_PluginError);
+    Py_CLEAR(sudo_exc_PluginReject);
+    Py_CLEAR(sudo_exc_ConversationInterrupted);
+
+    // Free base plugin
+    Py_CLEAR(sudo_type_Plugin);
+
+    // Free conversation message type
+    Py_CLEAR(sudo_type_ConvMessage);
+
+    debug_return;
+}

plugins/python/sudo_python_module.h

@@ -29,6 +29,7 @@ extern PyObject *sudo_exc_PluginReject;  // a reject with message
 extern PyObject *sudo_exc_PluginError;   // an error with message
 
 extern PyTypeObject *sudo_type_Plugin;
+extern PyTypeObject *sudo_type_ConvMessage;
 
 PyObject *sudo_module_create_class(const char *class_name, PyMethodDef *class_methods,
                                    PyObject *base_class);