https://github.com/python/cpython/commit/afec6a546049b80fdbaf18baa3a4d2cbc535ce58 commit: afec6a546049b80fdbaf18baa3a4d2cbc535ce58 branch: 3.13 author: yihong <[email protected]> committer: ZeroIntensity <[email protected]> date: 2025-09-10T12:54:42-04:00 summary:
[3.13] gh-134163: Fix an infinite loop when the process runs out of memory in a `try` block (GH-138491) Signed-off-by: yihong0618 <[email protected]> Co-authored-by: Peter Bierma <[email protected]> files: A Misc/NEWS.d/next/Core_and_Builtins/2025-09-04-11-52-23.gh-issue-134163.EqKyn8.rst M Lib/test/test_exceptions.py M Python/ceval.c diff --git a/Lib/test/test_exceptions.py b/Lib/test/test_exceptions.py index c91f66629483e5..939783956d62d6 100644 --- a/Lib/test/test_exceptions.py +++ b/Lib/test/test_exceptions.py @@ -1843,6 +1843,38 @@ def test_memory_error_in_subinterp(self): rc, _, err = script_helper.assert_python_ok("-c", code) self.assertIn(b'MemoryError', err) + @cpython_only + # Python built with Py_TRACE_REFS fail with a fatal error in + # _PyRefchain_Trace() on memory allocation error. + @unittest.skipIf(support.Py_TRACE_REFS, 'cannot test Py_TRACE_REFS build') + def test_exec_set_nomemory_hang(self): + import_module("_testcapi") + # gh-134163: A MemoryError inside code that was wrapped by a try/except + # block would lead to an infinite loop. + + # The frame_lasti needs to be greater than 257 to prevent + # PyLong_FromLong() from returning cached integers, which + # don't require a memory allocation. Prepend some dummy code + # to artificially increase the instruction index. + warmup_code = "a = list(range(0, 1))\n" * 20 + user_input = warmup_code + dedent(""" + try: + import _testcapi + _testcapi.set_nomemory(0) + b = list(range(1000, 2000)) + except Exception as e: + import traceback + traceback.print_exc() + """) + with SuppressCrashReport(): + with script_helper.spawn_python('-c', user_input) as p: + p.wait() + output = p.stdout.read() + + self.assertIn(p.returncode, (0, 1)) + self.assertGreater(len(output), 0) # At minimum, should not hang + self.assertIn(b"MemoryError", output) + class NameErrorTests(unittest.TestCase): def test_name_error_has_name(self): diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-09-04-11-52-23.gh-issue-134163.EqKyn8.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-09-04-11-52-23.gh-issue-134163.EqKyn8.rst new file mode 100644 index 00000000000000..24e8efda2b627d --- /dev/null +++ b/Misc/NEWS.d/next/Core_and_Builtins/2025-09-04-11-52-23.gh-issue-134163.EqKyn8.rst @@ -0,0 +1 @@ +Fix a hang when the process is out of memory inside an exception handler. diff --git a/Python/ceval.c b/Python/ceval.c index 8c0cb29863cc60..511e39f0c2e2dd 100644 --- a/Python/ceval.c +++ b/Python/ceval.c @@ -912,7 +912,11 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int int frame_lasti = _PyInterpreterFrame_LASTI(frame); PyObject *lasti = PyLong_FromLong(frame_lasti); if (lasti == NULL) { - goto exception_unwind; + // Instead of going back to exception_unwind (which would cause + // infinite recursion), directly exit to let the original exception + // propagate up and hopefully be handled at a higher level. + _PyFrame_SetStackPointer(frame, stack_pointer); + goto exit_unwind; } PUSH(lasti); } _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3//lists/python-checkins.python.org Member address: [email protected]
