From: sobolevn <mail@sobolevn.me>
Date: Mon, 13 Jan 2025 07:40:52 +0000 (+0300)
Subject: gh-128759: fix data race in `type_modified_unlocked` (#128764)
X-Git-Tag: v3.14.0a4~29
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=6e1e78054060ad326f26dd8dbf12adfedbb52883;p=thirdparty%2FPython%2Fcpython.git

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

diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index 680846f1c0b8..0f5ebc6f9077 100644
--- 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.