bpo-27863: Fixed multiple crashes in ElementTree. (#765)

This commit is contained in:
Serhiy Storchaka 2017-03-30 09:47:31 +03:00 committed by GitHub
parent 918403cfc3
commit 576def096e
3 changed files with 167 additions and 48 deletions

View File

@ -1879,6 +1879,118 @@ class BadElementTest(ElementTestCase, unittest.TestCase):
with self.assertRaises(RuntimeError):
repr(e) # Should not crash
def test_element_get_text(self):
# Issue #27863
class X(str):
def __del__(self):
try:
elem.text
except NameError:
pass
b = ET.TreeBuilder()
b.start('tag', {})
b.data('ABCD')
b.data(X('EFGH'))
b.data('IJKL')
b.end('tag')
elem = b.close()
self.assertEqual(elem.text, 'ABCDEFGHIJKL')
def test_element_get_tail(self):
# Issue #27863
class X(str):
def __del__(self):
try:
elem[0].tail
except NameError:
pass
b = ET.TreeBuilder()
b.start('root', {})
b.start('tag', {})
b.end('tag')
b.data('ABCD')
b.data(X('EFGH'))
b.data('IJKL')
b.end('root')
elem = b.close()
self.assertEqual(elem[0].tail, 'ABCDEFGHIJKL')
def test_element_iter(self):
# Issue #27863
state = {
'tag': 'tag',
'_children': [None], # non-Element
'attrib': 'attr',
'tail': 'tail',
'text': 'text',
}
e = ET.Element('tag')
try:
e.__setstate__(state)
except AttributeError:
e.__dict__ = state
it = e.iter()
self.assertIs(next(it), e)
self.assertRaises(AttributeError, next, it)
def test_subscr(self):
# Issue #27863
class X:
def __index__(self):
del e[:]
return 1
e = ET.Element('elem')
e.append(ET.Element('child'))
e[:X()] # shouldn't crash
e.append(ET.Element('child'))
e[0:10:X()] # shouldn't crash
def test_ass_subscr(self):
# Issue #27863
class X:
def __index__(self):
e[:] = []
return 1
e = ET.Element('elem')
for _ in range(10):
e.insert(0, ET.Element('child'))
e[0:10:X()] = [] # shouldn't crash
def test_treebuilder_start(self):
# Issue #27863
def element_factory(x, y):
return []
b = ET.TreeBuilder(element_factory=element_factory)
b.start('tag', {})
b.data('ABCD')
self.assertRaises(AttributeError, b.start, 'tag2', {})
del b
gc_collect()
def test_treebuilder_end(self):
# Issue #27863
def element_factory(x, y):
return []
b = ET.TreeBuilder(element_factory=element_factory)
b.start('tag', {})
b.data('ABCD')
self.assertRaises(AttributeError, b.end, 'tag')
del b
gc_collect()
class MutatingElementPath(str):
def __new__(cls, elem, *args):
self = str.__new__(cls, *args)

View File

@ -298,6 +298,9 @@ Extension Modules
Library
-------
- bpo-27863: Fixed multiple crashes in ElementTree caused by race conditions
and wrong types.
- bpo-25996: Added support of file descriptors in os.scandir() on Unix.
os.fwalk() is sped up by 2 times by using os.scandir().

View File

@ -131,7 +131,7 @@ elementtree_free(void *m)
LOCAL(PyObject*)
list_join(PyObject* list)
{
/* join list elements (destroying the list in the process) */
/* join list elements */
PyObject* joiner;
PyObject* result;
@ -140,8 +140,6 @@ list_join(PyObject* list)
return NULL;
result = PyUnicode_Join(joiner, list);
Py_DECREF(joiner);
if (result)
Py_DECREF(list);
return result;
}
@ -508,15 +506,17 @@ element_get_text(ElementObject* self)
{
/* return borrowed reference to text attribute */
PyObject* res = self->text;
PyObject *res = self->text;
if (JOIN_GET(res)) {
res = JOIN_OBJ(res);
if (PyList_CheckExact(res)) {
res = list_join(res);
if (!res)
PyObject *tmp = list_join(res);
if (!tmp)
return NULL;
self->text = res;
self->text = tmp;
Py_DECREF(res);
res = tmp;
}
}
@ -528,15 +528,17 @@ element_get_tail(ElementObject* self)
{
/* return borrowed reference to text attribute */
PyObject* res = self->tail;
PyObject *res = self->tail;
if (JOIN_GET(res)) {
res = JOIN_OBJ(res);
if (PyList_CheckExact(res)) {
res = list_join(res);
if (!res)
PyObject *tmp = list_join(res);
if (!tmp)
return NULL;
self->tail = res;
self->tail = tmp;
Py_DECREF(res);
res = tmp;
}
}
@ -2148,6 +2150,12 @@ elementiter_next(ElementIterObject *it)
continue;
}
if (!PyObject_TypeCheck(extra->children[child_index], &Element_Type)) {
PyErr_Format(PyExc_AttributeError,
"'%.100s' object has no attribute 'iter'",
Py_TYPE(extra->children[child_index])->tp_name);
return NULL;
}
elem = (ElementObject *)extra->children[child_index];
item->child_index++;
Py_INCREF(elem);
@ -2397,40 +2405,51 @@ treebuilder_dealloc(TreeBuilderObject *self)
/* helpers for handling of arbitrary element-like objects */
static int
treebuilder_set_element_text_or_tail(PyObject *element, PyObject *data,
treebuilder_set_element_text_or_tail(PyObject *element, PyObject **data,
PyObject **dest, _Py_Identifier *name)
{
if (Element_CheckExact(element)) {
Py_DECREF(JOIN_OBJ(*dest));
*dest = JOIN_SET(data, PyList_CheckExact(data));
PyObject *tmp = JOIN_OBJ(*dest);
*dest = JOIN_SET(*data, PyList_CheckExact(*data));
*data = NULL;
Py_DECREF(tmp);
return 0;
}
else {
PyObject *joined = list_join(data);
PyObject *joined = list_join(*data);
int r;
if (joined == NULL)
return -1;
r = _PyObject_SetAttrId(element, name, joined);
Py_DECREF(joined);
return r;
if (r < 0)
return -1;
Py_CLEAR(*data);
return 0;
}
}
/* These two functions steal a reference to data */
static int
treebuilder_set_element_text(PyObject *element, PyObject *data)
LOCAL(int)
treebuilder_flush_data(TreeBuilderObject* self)
{
_Py_IDENTIFIER(text);
return treebuilder_set_element_text_or_tail(
element, data, &((ElementObject *) element)->text, &PyId_text);
}
PyObject *element = self->last;
static int
treebuilder_set_element_tail(PyObject *element, PyObject *data)
{
_Py_IDENTIFIER(tail);
return treebuilder_set_element_text_or_tail(
element, data, &((ElementObject *) element)->tail, &PyId_tail);
if (!self->data) {
return 0;
}
if (self->this == element) {
_Py_IDENTIFIER(text);
return treebuilder_set_element_text_or_tail(
element, &self->data,
&((ElementObject *) element)->text, &PyId_text);
}
else {
_Py_IDENTIFIER(tail);
return treebuilder_set_element_text_or_tail(
element, &self->data,
&((ElementObject *) element)->tail, &PyId_tail);
}
}
static int
@ -2480,16 +2499,8 @@ treebuilder_handle_start(TreeBuilderObject* self, PyObject* tag,
PyObject* this;
elementtreestate *st = ET_STATE_GLOBAL;
if (self->data) {
if (self->this == self->last) {
if (treebuilder_set_element_text(self->last, self->data))
return NULL;
}
else {
if (treebuilder_set_element_tail(self->last, self->data))
return NULL;
}
self->data = NULL;
if (treebuilder_flush_data(self) < 0) {
return NULL;
}
if (!self->element_factory || self->element_factory == Py_None) {
@ -2594,15 +2605,8 @@ treebuilder_handle_end(TreeBuilderObject* self, PyObject* tag)
{
PyObject* item;
if (self->data) {
if (self->this == self->last) {
if (treebuilder_set_element_text(self->last, self->data))
return NULL;
} else {
if (treebuilder_set_element_tail(self->last, self->data))
return NULL;
}
self->data = NULL;
if (treebuilder_flush_data(self) < 0) {
return NULL;
}
if (self->index == 0) {