gh-128759: fix data race in `type_modified_unlocked` (#128764)

diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index 680846f1c0b865c1067f14507683a37fdbf3351b..0f5ebc6f90773d8f80856f143ac9084ca16a3297 100644 (file)
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -1038,7 +1038,7 @@ type_modified_unlocked(PyTypeObject *type)
        We don't assign new version tags eagerly, but only as
        needed.
      */
-    if (type->tp_version_tag == 0) {
+    if (FT_ATOMIC_LOAD_UINT_RELAXED(type->tp_version_tag) == 0) {
         return;
     }
     // Cannot modify static builtin types.