FazBrowse GitHub Viewer | Trending |
URL:
| Home
Tools: [Download Repo ZIP]   [Original HTTPS Page]

gh-114314: Avoid possibly invalid args when initializing a ctypes meta type by neonene · Pull Request #114740 · python/cpython · GitHub

/ cpython Public

gh-114314: Avoid possibly invalid args when initializing a ctypes meta type #114740

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
neonene wants to merge 2 commits into from
Conversation 0 Commits 2 Checks 0 Files changed
Closed

gh-114314: Avoid possibly invalid args when initializing a ctypes meta type #114740

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
baa1780
ready
neonene Mar 17, 2024
bc9c8cb
new experiment for CreateSwappedType() crash
neonene Mar 17, 2024
File filter

Filter by extension

Filter by extension .c  (1) .py  (1) All 2 file types selected
Viewed files
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Unified
Split
Hide whitespace
Diff view
Unified
Split
Hide whitespace
6 changes: 6 additions & 0 deletions Lib/test/test_ctypes/test_simplesubclasses.py
Show comments
View file
Open in desktop
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
Show hidden characters
Original file line number Diff line number Diff line change
Expand Up @@ -26,6 +26,12 @@ def test_type_flags(self):
self.assertTrue(_SimpleCData.__flags__ & Py_TPFLAGS_IMMUTABLETYPE)
self.assertFalse(_SimpleCData.__flags__ & Py_TPFLAGS_DISALLOW_INSTANTIATION)

def test_swapped_type_creation(self):
cls = PyCSimpleType.__new__(PyCSimpleType, '', (), {'_type_': 'i'})
PyCSimpleType.__init__(cls)
self.assertEqual(cls.__ctype_le__.__dict__.get('_type_'), 'i')
self.assertEqual(cls.__ctype_be__.__dict__.get('_type_'), 'i')

def test_compare(self):
self.assertEqual(MyInt(3), MyInt(3))
self.assertNotEqual(MyInt(42), MyInt(43))
Expand Down
108 changes: 68 additions & 40 deletions Modules/_ctypes/_ctypes.c
Show comments
View file
Open in desktop
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
Show hidden characters
Original file line number Diff line number Diff line change
Expand Up @@ -1847,6 +1847,42 @@ static PyMethodDef c_void_p_method = { "from_param", c_void_p_from_param, METH_O
static PyMethodDef c_char_p_method = { "from_param", c_char_p_from_param, METH_O };
static PyMethodDef c_wchar_p_method = { "from_param", c_wchar_p_from_param, METH_O };

// Complete arguments passed to PyCSimpleType_init() and CreateSwappedType()
static PyObject *
CreateSwappedType_ready(PyObject *self, PyObject *args)
{
PyObject *dict;
if (!PyTuple_CheckExact(args) || PyTuple_GET_SIZE(args) < 3) {
dict = PyDict_New();
}
else {
dict = PyDict_Copy(PyTuple_GET_ITEM(args, 2));
}
if (!dict) {
return NULL;
}
if (PyDict_Update(dict, ((PyTypeObject *)self)->tp_dict) < 0) {
Py_DECREF(dict);
return NULL;
}
if (PyDict_DelItem(dict, &_Py_ID(__dict__))) {
PyErr_Clear();
}
if (PyDict_DelItem(dict, &_Py_ID(__weakref__))) {
PyErr_Clear();
}

PyObject *safe_args = PyTuple_New(3);
if (!safe_args) {
Py_DECREF(dict);
return NULL;
}
PyTuple_SET_ITEM(safe_args, 0, PyType_GetName((PyTypeObject *)self));
PyTuple_SET_ITEM(safe_args, 1, Py_NewRef(((PyTypeObject *)self)->tp_bases));
PyTuple_SET_ITEM(safe_args, 2, dict);
return safe_args;
}

static PyObject *CreateSwappedType(PyTypeObject *type, PyObject *args, PyObject *kwds,
PyObject *proto, struct fielddesc *fmt)
{
Expand Down Expand Up @@ -1948,33 +1984,25 @@ PyCSimpleType_paramfunc(CDataObject *self)
return parg;
}

static PyObject *
PyCSimpleType_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
static int
PyCSimpleType_init(PyObject *self, PyObject *args, PyObject *kwds)
{
PyTypeObject *result;
StgDictObject *stgdict;
PyObject *proto;
const char *proto_str;
Py_ssize_t proto_len;
PyMethodDef *ml;
struct fielddesc *fmt;

/* create the new instance (which is a class,
since we are a metatype!) */
result = (PyTypeObject *)PyType_Type.tp_new(type, args, kwds);
if (result == NULL)
return NULL;

if (PyObject_GetOptionalAttr((PyObject *)result, &_Py_ID(_type_), &proto) < 0) {
return NULL;
if (PyObject_GetOptionalAttr(self, &_Py_ID(_type_), &proto) < 0) {
return -1;
}
if (!proto) {
PyErr_SetString(PyExc_AttributeError,
"class must define a '_type_' attribute");
error:
Py_XDECREF(proto);
Py_DECREF(result);
return NULL;
return -1;
}
if (PyUnicode_Check(proto)) {
proto_str = PyUnicode_AsUTF8AndSize(proto, &proto_len);
Expand Down Expand Up @@ -2023,15 +2051,14 @@ PyCSimpleType_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
stgdict->format = _ctypes_alloc_format_string_for_type(proto_str[0], 0);
#endif
if (stgdict->format == NULL) {
Py_DECREF(result);
Py_DECREF(proto);
Py_DECREF((PyObject *)stgdict);
return NULL;
return -1;
}

stgdict->paramfunc = PyCSimpleType_paramfunc;
/*
if (result->tp_base != st->Simple_Type) {
if (self->tp_base != st->Simple_Type) {
stgdict->setfunc = NULL;
stgdict->getfunc = NULL;
}
Expand All @@ -2041,17 +2068,16 @@ PyCSimpleType_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
stgdict->proto = proto;

/* replace the class dict by our updated spam dict */
if (-1 == PyDict_Update((PyObject *)stgdict, result->tp_dict)) {
Py_DECREF(result);
if (-1 == PyDict_Update((PyObject *)stgdict, ((PyTypeObject *)self)->tp_dict)) {
Py_DECREF((PyObject *)stgdict);
return NULL;
return -1;
}
Py_SETREF(result->tp_dict, (PyObject *)stgdict);
Py_SETREF(((PyTypeObject *)self)->tp_dict, (PyObject *)stgdict);

/* Install from_param class methods in ctypes base classes.
Overrides the PyCSimpleType_from_param generic method.
*/
if (result->tp_base == st->Simple_Type) {
if (((PyTypeObject *)self)->tp_base == st->Simple_Type) {
switch (*proto_str) {
case 'z': /* c_char_p */
ml = &c_char_p_method;
Expand Down Expand Up @@ -2079,57 +2105,59 @@ PyCSimpleType_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
if (ml) {
PyObject *meth;
int x;
meth = PyDescr_NewClassMethod(result, ml);
meth = PyDescr_NewClassMethod((PyTypeObject*)self, ml);
if (!meth) {
Py_DECREF(result);
return NULL;
return -1;
}
x = PyDict_SetItemString(result->tp_dict,
x = PyDict_SetItemString(((PyTypeObject*)self)->tp_dict,
ml->ml_name,
meth);
Py_DECREF(meth);
if (x == -1) {
Py_DECREF(result);
return NULL;
return -1;
}
}
}

PyTypeObject *type = Py_TYPE(self);
if (type == st->PyCSimpleType_Type
&& fmt->setfunc_swapped
&& fmt->getfunc_swapped)
{
PyObject *swapped = CreateSwappedType(type, args, kwds,
PyObject *safe_args = CreateSwappedType_ready(self, args);
if (!safe_args) {
return -1;
}
PyObject *swapped = CreateSwappedType(type, safe_args, kwds,
proto, fmt);
Py_DECREF(safe_args);
StgDictObject *sw_dict;
if (swapped == NULL) {
Py_DECREF(result);
return NULL;
return -1;
}
sw_dict = PyType_stgdict(swapped);
#ifdef WORDS_BIGENDIAN
PyObject_SetAttrString((PyObject *)result, "__ctype_le__", swapped);
PyObject_SetAttrString((PyObject *)result, "__ctype_be__", (PyObject *)result);
PyObject_SetAttrString(swapped, "__ctype_be__", (PyObject *)result);
PyObject_SetAttrString(self, "__ctype_le__", swapped);
PyObject_SetAttrString(self, "__ctype_be__", self);
PyObject_SetAttrString(swapped, "__ctype_be__", self);
PyObject_SetAttrString(swapped, "__ctype_le__", swapped);
/* We are creating the type for the OTHER endian */
sw_dict->format = _ctypes_alloc_format_string("<", stgdict->format+1);
#else
PyObject_SetAttrString((PyObject *)result, "__ctype_be__", swapped);
PyObject_SetAttrString((PyObject *)result, "__ctype_le__", (PyObject *)result);
PyObject_SetAttrString(swapped, "__ctype_le__", (PyObject *)result);
PyObject_SetAttrString(self, "__ctype_be__", swapped);
PyObject_SetAttrString(self, "__ctype_le__", self);
PyObject_SetAttrString(swapped, "__ctype_le__", self);
PyObject_SetAttrString(swapped, "__ctype_be__", swapped);
/* We are creating the type for the OTHER endian */
sw_dict->format = _ctypes_alloc_format_string(">", stgdict->format+1);
#endif
Py_DECREF(swapped);
if (PyErr_Occurred()) {
Py_DECREF(result);
return NULL;
return -1;
}
};

return (PyObject *)result;
return 0;
}

/*
Expand Down Expand Up @@ -2218,7 +2246,7 @@ static PyMethodDef PyCSimpleType_methods[] = {
static PyType_Slot pycsimple_type_slots[] = {
{Py_tp_doc, PyDoc_STR("metatype for the PyCSimpleType Objects")},
{Py_tp_methods, PyCSimpleType_methods},
{Py_tp_new, PyCSimpleType_new},
{Py_tp_init, PyCSimpleType_init},
{Py_tp_traverse, CDataType_traverse},
{Py_tp_clear, CDataType_clear},

Expand Down
Back | FazBrowse Home | New Git URL