From f57e8711c0289d7bc19a054d446b91ee76751f29 Mon Sep 17 00:00:00 2001
From: neonene <53406459+neonene@users.noreply.github.com>
Date: Sat, 8 Jun 2024 19:22:07 +0900
Subject: [PATCH] gh-120244: Fix re.sub() reference leak (GH-120245)

---
 .../next/Library/2024-06-08-09-45-31.gh-issue-120244.8o9Dzr.rst  | 1 +
 Modules/_sre/sre.c                                               | 1 +
 2 files changed, 2 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Library/2024-06-08-09-45-31.gh-issue-120244.8o9Dzr.rst

diff --git a/Misc/NEWS.d/next/Library/2024-06-08-09-45-31.gh-issue-120244.8o9Dzr.rst b/Misc/NEWS.d/next/Library/2024-06-08-09-45-31.gh-issue-120244.8o9Dzr.rst
new file mode 100644
index 00000000000000..d21532f22a1d38
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2024-06-08-09-45-31.gh-issue-120244.8o9Dzr.rst
@@ -0,0 +1 @@
+Fix memory leak in :func:`re.sub()` when the replacement string contains backreferences.
diff --git a/Modules/_sre/sre.c b/Modules/_sre/sre.c
index c1eff63d921de9..e33034086481c2 100644
--- a/Modules/_sre/sre.c
+++ b/Modules/_sre/sre.c
@@ -1622,6 +1622,7 @@ _sre_template_impl(PyObject *module, PyObject *pattern, PyObject *template)
         }
         self->items[i].literal = Py_XNewRef(literal);
     }
+    PyObject_GC_Track(self);
     return (PyObject*) self;
 
 bad_template: