From 63dd27da3ba17a9584907cf179c0f33ba92de98a Mon Sep 17 00:00:00 2001
From: Peter Bierma <zintensitydev@gmail.com>
Date: Fri, 19 Sep 2025 11:09:44 -0400
Subject: [PATCH] [3.13] gh-112729: Correctly fail when the process is out of
 memory during interpreter creation (GH-139164) (GH-139169)

* gh-112729: Correctly fail when the process is out of memory during interpreter creation (GH-139164)

(cherry picked from commit d06113c7a7cac76a28847702685e601b79f71bf8)
---
 Lib/test/test_interpreters/test_stress.py       |  9 +++++++++
 ...25-09-19-09-36-42.gh-issue-112729.mmty0_.rst |  2 ++
 Python/pylifecycle.c                            | 17 ++++++++---------
 3 files changed, 19 insertions(+), 9 deletions(-)
 create mode 100644 Misc/NEWS.d/next/Library/2025-09-19-09-36-42.gh-issue-112729.mmty0_.rst

diff --git a/Lib/test/test_interpreters/test_stress.py b/Lib/test/test_interpreters/test_stress.py
index fae2f38cb55..a39c9352f72 100644
--- a/Lib/test/test_interpreters/test_stress.py
+++ b/Lib/test/test_interpreters/test_stress.py
@@ -7,6 +7,7 @@ from test.support import threading_helper
 # Raise SkipTest if subinterpreters not supported.
 import_helper.import_module('_interpreters')
 from test.support import interpreters
+from test.support.interpreters import InterpreterError
 from .utils import TestBase
 
 
@@ -74,6 +75,14 @@ class StressTests(TestBase):
             start.set()
         support.gc_collect()
 
+    def test_create_interpreter_no_memory(self):
+        import _interpreters
+        _testcapi = import_helper.import_module("_testcapi")
+
+        with self.assertRaises(InterpreterError):
+            _testcapi.set_nomemory(0, 1)
+            _interpreters.create()
+
 
 if __name__ == '__main__':
     # Test needs to be a package, so we can do relative imports.
diff --git a/Misc/NEWS.d/next/Library/2025-09-19-09-36-42.gh-issue-112729.mmty0_.rst b/Misc/NEWS.d/next/Library/2025-09-19-09-36-42.gh-issue-112729.mmty0_.rst
new file mode 100644
index 00000000000..07485fcf9f1
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2025-09-19-09-36-42.gh-issue-112729.mmty0_.rst
@@ -0,0 +1,2 @@
+Fix crash when calling ``_interpreters.create`` when the
+process is out of memory.
diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index 01fd36e52fc..8cc6bd0fa78 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -2301,17 +2301,16 @@ new_interpreter(PyThreadState **tstate_p,
        interpreters: disable PyGILState_Check(). */
     runtime->gilstate.check_enabled = 0;
 
-    PyInterpreterState *interp = PyInterpreterState_New();
-    if (interp == NULL) {
-        *tstate_p = NULL;
-        return _PyStatus_OK();
-    }
-    _PyInterpreterState_SetWhence(interp, whence);
-    interp->_ready = 1;
-
     // XXX Might new_interpreter() have been called without the GIL held?
     PyThreadState *save_tstate = _PyThreadState_GET();
     PyThreadState *tstate = NULL;
+    PyInterpreterState *interp;
+    status = _PyInterpreterState_New(save_tstate, &interp);
+    if (interp == NULL) {
+        goto error;
+    }
+    _PyInterpreterState_SetWhence(interp, whence);
+    interp->_ready = 1;
 
     /* From this point until the init_interp_create_gil() call,
        we must not do anything that requires that the GIL be held
@@ -2388,7 +2387,7 @@ error:
     *tstate_p = NULL;
     if (tstate != NULL) {
         Py_EndInterpreter(tstate);
-    } else {
+    } else if (interp != NULL) {
         PyInterpreterState_Delete(interp);
     }
     if (save_tstate != NULL) {