https://github.com/python/cpython/commit/2ee87913dde038436a25f1db13ee3fddd2b... commit: 2ee87913dde038436a25f1db13ee3fddd2bcc983 branch: 3.8 author: Dong-hee Na <donghee.na92@gmail.com> committer: Pablo Galindo <Pablogsal@gmail.com> date: 2019-12-31T04:15:36Z summary: [3.8] bpo-38588: Fix possible crashes in dict and list when calling P… (GH-17764) * [3.8] bpo-38588: Fix possible crashes in dict and list when calling PyObject_RichCompareBool (GH-17734) Take strong references before calling PyObject_RichCompareBool to protect against the case where the object dies during the call. (cherry picked from commit 2d5bf568eaa5059402ccce9ba5a366986ba27c8a) Co-authored-by: Dong-hee Na <donghee.na92@gmail.com> * Update Objects/listobject.c @methane's suggestion Co-Authored-By: Inada Naoki <songofacandy@gmail.com> Co-authored-by: Inada Naoki <songofacandy@gmail.com> files: A Misc/NEWS.d/next/Core and Builtins/2019-12-29-19-13-54.bpo-38588.pgXnNS.rst M Lib/test/test_dict.py M Lib/test/test_list.py M Objects/dictobject.c M Objects/listobject.c diff --git a/Lib/test/test_dict.py b/Lib/test/test_dict.py index 5b513765f7b08..de483ab552155 100644 --- a/Lib/test/test_dict.py +++ b/Lib/test/test_dict.py @@ -1221,7 +1221,7 @@ def test_free_after_iterating(self): support.check_free_after_iterating(self, lambda d: iter(d.items()), dict) def test_equal_operator_modifying_operand(self): - # test fix for seg fault reported in issue 27945 part 3. + # test fix for seg fault reported in bpo-27945 part 3. class X(): def __del__(self): dict_b.clear() @@ -1237,6 +1237,16 @@ def __hash__(self): dict_b = {X(): X()} self.assertTrue(dict_a == dict_b) + # test fix for seg fault reported in bpo-38588 part 1. + class Y: + def __eq__(self, other): + dict_d.clear() + return True + + dict_c = {0: Y()} + dict_d = {0: set()} + self.assertTrue(dict_c == dict_d) + def test_fromkeys_operator_modifying_dict_operand(self): # test fix for seg fault reported in issue 27945 part 4a. class X(int): diff --git a/Lib/test/test_list.py b/Lib/test/test_list.py index 55c6eede527c2..f4dcced9c167f 100644 --- a/Lib/test/test_list.py +++ b/Lib/test/test_list.py @@ -158,6 +158,31 @@ class L(list): pass with self.assertRaises(TypeError): (3,) + L([1,2]) + def test_equal_operator_modifying_operand(self): + # test fix for seg fault reported in bpo-38588 part 2. + class X: + def __eq__(self,other) : + list2.clear() + return NotImplemented + + class Y: + def __eq__(self, other): + list1.clear() + return NotImplemented + + class Z: + def __eq__(self, other): + list3.clear() + return NotImplemented + + list1 = [X()] + list2 = [Y()] + self.assertTrue(list1 == list2) + + list3 = [Z()] + list4 = [1] + self.assertFalse(list3 == list4) + @cpython_only def test_preallocation(self): iterable = [0] * 10 diff --git a/Misc/NEWS.d/next/Core and Builtins/2019-12-29-19-13-54.bpo-38588.pgXnNS.rst b/Misc/NEWS.d/next/Core and Builtins/2019-12-29-19-13-54.bpo-38588.pgXnNS.rst new file mode 100644 index 0000000000000..0b81085a89d25 --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2019-12-29-19-13-54.bpo-38588.pgXnNS.rst @@ -0,0 +1,2 @@ +Fix possible crashes in dict and list when calling +:c:func:`PyObject_RichCompareBool`. diff --git a/Objects/dictobject.c b/Objects/dictobject.c index 76f4fefe0979f..3c56f4a515e8a 100644 --- a/Objects/dictobject.c +++ b/Objects/dictobject.c @@ -2773,9 +2773,11 @@ dict_equal(PyDictObject *a, PyDictObject *b) return -1; return 0; } + Py_INCREF(bval); cmp = PyObject_RichCompareBool(aval, bval, Py_EQ); Py_DECREF(key); Py_DECREF(aval); + Py_DECREF(bval); if (cmp <= 0) /* error or not equal */ return cmp; } diff --git a/Objects/listobject.c b/Objects/listobject.c index 8b52fa5ef267a..d506c0817336b 100644 --- a/Objects/listobject.c +++ b/Objects/listobject.c @@ -2664,8 +2664,18 @@ list_richcompare(PyObject *v, PyObject *w, int op) /* Search for the first index where items are different */ for (i = 0; i < Py_SIZE(vl) && i < Py_SIZE(wl); i++) { + PyObject *vitem = vl->ob_item[i]; + PyObject *witem = wl->ob_item[i]; + if (vitem == witem) { + continue; + } + + Py_INCREF(vitem); + Py_INCREF(witem); int k = PyObject_RichCompareBool(vl->ob_item[i], wl->ob_item[i], Py_EQ); + Py_DECREF(vitem); + Py_DECREF(witem); if (k < 0) return NULL; if (!k)