https://github.com/python/cpython/commit/1fb72d2ad243c965d4432b4e93884064001... commit: 1fb72d2ad243c965d4432b4e93884064001a2607 branch: master author: Serhiy Storchaka <storchaka@gmail.com> committer: GitHub <noreply@github.com> date: 2017-12-03T22:12:11+02:00 summary: bpo-32137: The repr of deeply nested dict now raises a RecursionError (#4570) instead of crashing due to a stack overflow. This perhaps will fix similar problems in other extension types. files: A Misc/NEWS.d/next/Core and Builtins/2017-11-26-14-36-30.bpo-32137.Stj5nL.rst M Lib/test/list_tests.py M Lib/test/mapping_tests.py M Lib/test/test_dict.py M Objects/listobject.c M Objects/object.c M Objects/tupleobject.c diff --git a/Lib/test/list_tests.py b/Lib/test/list_tests.py index ce9db9a1b8b..ed63fda20c1 100644 --- a/Lib/test/list_tests.py +++ b/Lib/test/list_tests.py @@ -53,10 +53,11 @@ def test_repr(self): self.assertEqual(str(a2), "[0, 1, 2, [...], 3]") self.assertEqual(repr(a2), "[0, 1, 2, [...], 3]") - l0 = [] + def test_repr_deep(self): + a = self.type2test([]) for i in range(sys.getrecursionlimit() + 100): - l0 = [l0] - self.assertRaises(RecursionError, repr, l0) + a = self.type2test([a]) + self.assertRaises(RecursionError, repr, a) def test_print(self): d = self.type2test(range(200)) diff --git a/Lib/test/mapping_tests.py b/Lib/test/mapping_tests.py index ff82f4eb7d8..53f29f60538 100644 --- a/Lib/test/mapping_tests.py +++ b/Lib/test/mapping_tests.py @@ -1,6 +1,7 @@ # tests common to dict and UserDict import unittest import collections +import sys class BasicTestMappingProtocol(unittest.TestCase): @@ -619,6 +620,14 @@ def __repr__(self): d = self._full_mapping({1: BadRepr()}) self.assertRaises(Exc, repr, d) + def test_repr_deep(self): + d = self._empty_mapping() + for i in range(sys.getrecursionlimit() + 100): + d0 = d + d = self._empty_mapping() + d[1] = d0 + self.assertRaises(RecursionError, repr, d) + def test_eq(self): self.assertEqual(self._empty_mapping(), self._empty_mapping()) self.assertEqual(self._full_mapping({1: 2}), diff --git a/Lib/test/test_dict.py b/Lib/test/test_dict.py index 8013f37c88d..4386eda3ae4 100644 --- a/Lib/test/test_dict.py +++ b/Lib/test/test_dict.py @@ -468,6 +468,12 @@ def __repr__(self): d = {1: BadRepr()} self.assertRaises(Exc, repr, d) + def test_repr_deep(self): + d = {} + for i in range(sys.getrecursionlimit() + 100): + d = {1: d} + self.assertRaises(RecursionError, repr, d) + def test_eq(self): self.assertEqual({}, {}) self.assertEqual({1: 2}, {1: 2}) diff --git a/Misc/NEWS.d/next/Core and Builtins/2017-11-26-14-36-30.bpo-32137.Stj5nL.rst b/Misc/NEWS.d/next/Core and Builtins/2017-11-26-14-36-30.bpo-32137.Stj5nL.rst new file mode 100644 index 00000000000..f8f4ab93c9e --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2017-11-26-14-36-30.bpo-32137.Stj5nL.rst @@ -0,0 +1,2 @@ +The repr of deeply nested dict now raises a RecursionError instead of +crashing due to a stack overflow. diff --git a/Objects/listobject.c b/Objects/listobject.c index 8576b7ae683..8794e37364a 100644 --- a/Objects/listobject.c +++ b/Objects/listobject.c @@ -364,10 +364,7 @@ list_repr(PyListObject *v) goto error; } - if (Py_EnterRecursiveCall(" while getting the repr of a list")) - goto error; s = PyObject_Repr(v->ob_item[i]); - Py_LeaveRecursiveCall(); if (s == NULL) goto error; diff --git a/Objects/object.c b/Objects/object.c index 674180d7203..a0d651d0805 100644 --- a/Objects/object.c +++ b/Objects/object.c @@ -463,7 +463,12 @@ PyObject_Repr(PyObject *v) assert(!PyErr_Occurred()); #endif + /* It is possible for a type to have a tp_repr representation that loops + infinitely. */ + if (Py_EnterRecursiveCall(" while getting the repr of an object")) + return NULL; res = (*v->ob_type->tp_repr)(v); + Py_LeaveRecursiveCall(); if (res == NULL) return NULL; if (!PyUnicode_Check(res)) { diff --git a/Objects/tupleobject.c b/Objects/tupleobject.c index 964db3bb8de..3a609461251 100644 --- a/Objects/tupleobject.c +++ b/Objects/tupleobject.c @@ -303,10 +303,7 @@ tuplerepr(PyTupleObject *v) goto error; } - if (Py_EnterRecursiveCall(" while getting the repr of a tuple")) - goto error; s = PyObject_Repr(v->ob_item[i]); - Py_LeaveRecursiveCall(); if (s == NULL) goto error;