From: Sam Gross <colesbury@gmail.com>
Date: Fri, 7 Feb 2025 14:44:24 +0000 (-0500)
Subject: gh-117657: Fix data race in `dict_dict_merge` (gh-129755)
X-Git-Tag: v3.14.0a5~68
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=34379d0a593e5a76e2f754cdd7fccb79f25a4613;p=thirdparty%2FPython%2Fcpython.git

gh-117657: Fix data race in `dict_dict_merge` (gh-129755)

Found while running `test_load_attr_module` from `test_opcache` under TSan.
---

diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 91cf013a1dc2..d979cd72b48e 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -3793,7 +3793,7 @@ dict_dict_merge(PyInterpreterState *interp, PyDictObject *mp, PyDictObject *othe
 
             ensure_shared_on_resize(mp);
             dictkeys_decref(interp, mp->ma_keys, IS_DICT_SHARED(mp));
-            mp->ma_keys = keys;
+            set_keys(mp, keys);
             STORE_USED(mp, other->ma_used);
             ASSERT_CONSISTENT(mp);