gh-115649: Copy the filename into main interpreter before intern in import.c (#120315)

Co-authored-by: Kumar Aditya <kumaraditya@python.org>

1 files changed, 11 insertions, 1 deletions

diff --git a/Python/import.c b/Python/import.c
index 2c7a461..9328819 100644
--- a/Python/import.c
+++ b/Python/import.c
@@ -1969,7 +1969,17 @@ import_run_extension(PyThreadState *tstate, PyModInitFunction p0,
             if (info->filename != NULL) {
                 // XXX There's a refleak somewhere with the filename.
                 // Until we can track it down, we intern it.
-                PyObject *filename = Py_NewRef(info->filename);
+                PyObject *filename = NULL;
+                if (switched) {
+                    // The original filename may be allocated by subinterpreter's
+                    // obmalloc, so we create a copy here.
+                    filename = _PyUnicode_Copy(info->filename);
+                    if (filename == NULL) {
+                        return NULL;
+                    }
+                } else {
+                    filename = Py_NewRef(info->filename);
+                }
                 PyUnicode_InternInPlace(&filename);
                 if (PyModule_AddObjectRef(mod, "__file__", filename) < 0) {
                     PyErr_Clear(); /* Not important enough to report */