From: Shamil <ashm.tech@proton.me>
Date: Fri, 19 Dec 2025 19:07:11 +0000 (+0300)
Subject: gh-142476: fix memory leak when creating JIT executors (GH-142492)
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e2a7db717507a66b49bb796391530147b3acab93;p=thirdparty%2FPython%2Fcpython.git

gh-142476: fix memory leak when creating JIT executors (GH-142492)
---

diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-12-13-01-11-03.gh-issue-142476.44Sp4N.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-12-13-01-11-03.gh-issue-142476.44Sp4N.rst
new file mode 100644
index 000000000000..eae1f3a1ce53
--- /dev/null
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2025-12-13-01-11-03.gh-issue-142476.44Sp4N.rst
@@ -0,0 +1,2 @@
+Fix a memory leak in the experimental Tier 2 optimizer when creating
+executors. Patched by Shamil Abdulaev.
diff --git a/Python/optimizer.c b/Python/optimizer.c
index 1e905850e3de..16abced6edbe 100644
--- a/Python/optimizer.c
+++ b/Python/optimizer.c
@@ -185,12 +185,17 @@ _PyOptimizer_Optimize(
     else {
         executor->vm_data.code = NULL;
     }
+    executor->vm_data.chain_depth = chain_depth;
+    assert(executor->vm_data.valid);
     _PyExitData *exit = _tstate->jit_tracer_state.initial_state.exit;
     if (exit != NULL) {
         exit->executor = executor;
     }
-    executor->vm_data.chain_depth = chain_depth;
-    assert(executor->vm_data.valid);
+    else {
+        // An executor inserted into the code object now has a strong reference
+        // to it from the code object. Thus, we don't need this reference anymore.
+        Py_DECREF(executor);
+    }
     interp->compiling = false;
     return 1;
 #else