gh-140306: Fix memory leaks in cross-interpreter data handling

Author: ashm-dev

Misc/NEWS.d/next/Core_and_Builtins/2025-10-18-21-29-45.gh-issue-140306.xS5CcS.rst

@@ -0,0 +1,2 @@
+Fix memory leaks in cross-interpreter channel operations and shared
+namespace handling

Modules/_interpchannelsmodule.c

@@ -580,7 +580,7 @@ _channelitem_clear_data(_channelitem *item, int removed)
 {
     if (item->data != NULL) {
         // It was allocated in channel_send().
-        (void)_release_xid_data(item->data, XID_IGNORE_EXC & XID_FREE);
+        (void)_release_xid_data(item->data, XID_IGNORE_EXC | XID_FREE);
         item->data = NULL;
     }
 

Python/crossinterp.c

@@ -1153,8 +1153,8 @@ _release_xid_data(_PyXIData_t *xidata, int rawfree)
 {
     PyObject *exc = PyErr_GetRaisedException();
     int res = rawfree
-        ? _PyXIData_Release(xidata)
-        : _PyXIData_ReleaseAndRawFree(xidata);
+        ? _PyXIData_ReleaseAndRawFree(xidata)
+        : _PyXIData_Release(xidata);
     if (res < 0) {
         /* The owning interpreter is already destroyed. */
         _PyXIData_Clear(NULL, xidata);
@@ -1814,6 +1814,7 @@ _PyXI_InitFailure(_PyXI_failure *failure, _PyXI_errcode code, PyObject *obj)
     const char *msg = _copy_string_obj_raw(msgobj, NULL);
     Py_DECREF(msgobj);
     if (PyErr_Occurred()) {
+        PyMem_RawFree((void *)msg);
         return -1;
     }
     *failure = (_PyXI_failure){