From 022b44f2546c44183e4df7b67e3e64502fae9143 Mon Sep 17 00:00:00 2001 From: Irit Katriel <1055913+iritkatriel@users.noreply.github.com> Date: Mon, 20 Feb 2023 22:16:09 +0000 Subject: [PATCH] gh-102056: Fix a few bugs in error handling of exception printing code (#102078) --- Lib/test/test_threading.py | 31 +++++++++++++++++++ ...-02-20-15-18-33.gh-issue-102056.uHKuwH.rst | 1 + Python/pythonrun.c | 23 +++++++++----- 3 files changed, 48 insertions(+), 7 deletions(-) create mode 100644 Misc/NEWS.d/next/Core and Builtins/2023-02-20-15-18-33.gh-issue-102056.uHKuwH.rst diff --git a/Lib/test/test_threading.py b/Lib/test/test_threading.py index 7fea2d38673eff..a39a267b403d83 100644 --- a/Lib/test/test_threading.py +++ b/Lib/test/test_threading.py @@ -1523,6 +1523,37 @@ def run(): self.assertEqual(out, b'') self.assertNotIn("Unhandled exception", err.decode()) + def test_print_exception_gh_102056(self): + # This used to crash. See gh-102056. + script = r"""if True: + import time + import threading + import _thread + + def f(): + try: + f() + except RecursionError: + f() + + def g(): + try: + raise ValueError() + except* ValueError: + f() + + def h(): + time.sleep(1) + _thread.interrupt_main() + + t = threading.Thread(target=h) + t.start() + g() + t.join() + """ + + assert_python_failure("-c", script) + def test_bare_raise_in_brand_new_thread(self): def bare_raise(): raise diff --git a/Misc/NEWS.d/next/Core and Builtins/2023-02-20-15-18-33.gh-issue-102056.uHKuwH.rst b/Misc/NEWS.d/next/Core and Builtins/2023-02-20-15-18-33.gh-issue-102056.uHKuwH.rst new file mode 100644 index 00000000000000..78cd525b365fe5 --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2023-02-20-15-18-33.gh-issue-102056.uHKuwH.rst @@ -0,0 +1 @@ +Fix error handling bugs in interpreter's exception printing code, which could cause a crash on infinite recursion. diff --git a/Python/pythonrun.c b/Python/pythonrun.c index ce993ea8796cb7..34a44dd92847ba 100644 --- a/Python/pythonrun.c +++ b/Python/pythonrun.c @@ -1246,8 +1246,7 @@ print_chained(struct exception_print_context* ctx, PyObject *value, const char * message, const char *tag) { PyObject *f = ctx->file; - - if (_Py_EnterRecursiveCall(" in print_chained") < 0) { + if (_Py_EnterRecursiveCall(" in print_chained")) { return -1; } bool need_close = ctx->need_close; @@ -1374,7 +1373,9 @@ print_exception_group(struct exception_print_context *ctx, PyObject *value) if (ctx->exception_group_depth == 0) { ctx->exception_group_depth += 1; } - print_exception(ctx, value); + if (print_exception(ctx, value) < 0) { + return -1; + } PyObject *excs = ((PyBaseExceptionGroupObject *)value)->excs; assert(excs && PyTuple_Check(excs)); @@ -1424,7 +1425,7 @@ print_exception_group(struct exception_print_context *ctx, PyObject *value) PyObject *exc = PyTuple_GET_ITEM(excs, i); if (!truncated) { - if (_Py_EnterRecursiveCall(" in print_exception_group") != 0) { + if (_Py_EnterRecursiveCall(" in print_exception_group")) { return -1; } int res = print_exception_recursive(ctx, exc); @@ -1477,22 +1478,30 @@ print_exception_group(struct exception_print_context *ctx, PyObject *value) static int print_exception_recursive(struct exception_print_context *ctx, PyObject *value) { + if (_Py_EnterRecursiveCall(" in print_exception_recursive")) { + return -1; + } if (ctx->seen != NULL) { /* Exception chaining */ if (print_exception_cause_and_context(ctx, value) < 0) { - return -1; + goto error; } } if (!_PyBaseExceptionGroup_Check(value)) { if (print_exception(ctx, value) < 0) { - return -1; + goto error; } } else if (print_exception_group(ctx, value) < 0) { - return -1; + goto error; } assert(!PyErr_Occurred()); + + _Py_LeaveRecursiveCall(); return 0; +error: + _Py_LeaveRecursiveCall(); + return -1; } #define PyErr_MAX_GROUP_WIDTH 15