Skip to content

[3.7] bpo-35961: Fix a crash in slice_richcompare() (GH-11830) #11839

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

Merged
miss-islington merged 1 commit into from
Feb 13, 2019
Merged

[3.7] bpo-35961: Fix a crash in slice_richcompare() (GH-11830) #11839

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 2 additions & 0 deletions Misc/NEWS.d/next/Core and Builtins/2019-02-12-20-16-34.bpo-35961.7f7Sne.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,2 @@
Fix a crash in slice_richcompare(): use strong references rather than stolen
references for the two temporary internal tuples.
38 changes: 14 additions & 24 deletions Objects/sliceobject.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -564,14 +564,11 @@ static PyMethodDef slice_methods[] = {
static PyObject *
slice_richcompare(PyObject *v, PyObject *w, int op)
{
PyObject *t1;
PyObject *t2;
PyObject *res;

if (!PySlice_Check(v) || !PySlice_Check(w))
Py_RETURN_NOTIMPLEMENTED;

if (v == w) {
PyObject *res;
/* XXX Do we really need this shortcut?
There's a unit test for it, but is that fair? */
switch (op) {
Expand All @@ -588,34 +585,27 @@ slice_richcompare(PyObject *v, PyObject *w, int op)
return res;
}

t1 = PyTuple_New(3);
if (t1 == NULL)

PyObject *t1 = PyTuple_Pack(3,
((PySliceObject *)v)->start,
((PySliceObject *)v)->stop,
((PySliceObject *)v)->step);
if (t1 == NULL) {
return NULL;
t2 = PyTuple_New(3);
}

PyObject *t2 = PyTuple_Pack(3,
((PySliceObject *)w)->start,
((PySliceObject *)w)->stop,
((PySliceObject *)w)->step);
if (t2 == NULL) {
Py_DECREF(t1);
return NULL;
}

PyTuple_SET_ITEM(t1, 0, ((PySliceObject *)v)->start);
PyTuple_SET_ITEM(t1, 1, ((PySliceObject *)v)->stop);
PyTuple_SET_ITEM(t1, 2, ((PySliceObject *)v)->step);
PyTuple_SET_ITEM(t2, 0, ((PySliceObject *)w)->start);
PyTuple_SET_ITEM(t2, 1, ((PySliceObject *)w)->stop);
PyTuple_SET_ITEM(t2, 2, ((PySliceObject *)w)->step);

res = PyObject_RichCompare(t1, t2, op);

PyTuple_SET_ITEM(t1, 0, NULL);
PyTuple_SET_ITEM(t1, 1, NULL);
PyTuple_SET_ITEM(t1, 2, NULL);
PyTuple_SET_ITEM(t2, 0, NULL);
PyTuple_SET_ITEM(t2, 1, NULL);
PyTuple_SET_ITEM(t2, 2, NULL);

PyObject *res = PyObject_RichCompare(t1, t2, op);
Py_DECREF(t1);
Py_DECREF(t2);

return res;
}

Expand Down