gh-145376: Fix various reference leaks

Author: JelleZijlstra

Misc/NEWS.d/next/Core_and_Builtins/2026-02-28-16-46-17.gh-issue-145376.lG5u1a.rst

@@ -0,0 +1 @@
+Fix reference leaks in various unusual error scenarios.

Modules/main.c

@@ -506,6 +506,7 @@ pymain_run_interactive_hook(int *exitcode)
     }
 
     if (PySys_Audit("cpython.run_interactivehook", "O", hook) < 0) {
+        Py_DECREF(hook);
         goto error;
     }
 

Python/crossinterp.c

@@ -609,6 +609,7 @@ check_missing___main___attr(PyObject *exc)
     // Get the error message.
     PyObject *args = PyException_GetArgs(exc);
     if (args == NULL || args == Py_None || PyObject_Size(args) < 1) {
+        Py_XDECREF(args);
         assert(!PyErr_Occurred());
         return 0;
     }

Python/import.c

@@ -5638,6 +5638,7 @@ _imp__set_lazy_attributes_impl(PyObject *module, PyObject *modobj,
 
     module_dict = get_mod_dict(modobj);
     if (module_dict == NULL || !PyDict_CheckExact(module_dict)) {
+        Py_DECREF(lazy_submodules);
         goto done;
     }
 

Python/pythonrun.c

@@ -1145,6 +1145,7 @@ _PyErr_Display(PyObject *file, PyObject *unused, PyObject *value, PyObject *tb)
         "traceback",
         "_print_exception_bltin");
     if (print_exception_fn == NULL || !PyCallable_Check(print_exception_fn)) {
+        Py_XDECREF(print_exception_fn);
         goto fallback;
     }
 

Python/sysmodule.c

@@ -1762,7 +1762,7 @@ sys_getwindowsversion_impl(PyObject *module)
     PyObject *realVersion = _sys_getwindowsversion_from_kernel32();
     if (!realVersion) {
         if (!PyErr_ExceptionMatches(PyExc_WindowsError)) {
-            return NULL;
+            goto error;
         }
 
         PyErr_Clear();