[3.10] bpo-45826: Fix a crash in suggestions.c by checking for `traceback is None` (GH-29590) (GH-29602)
(cherry picked from commit 5d90c467c02ffefdb13c1abc83a171db1a99ffad)
Co-authored-by: Dennis Sweeney <36520290+sweeneyde@users.noreply.github.com>
diff --git a/Python/suggestions.c b/Python/suggestions.c
index 7fd62fb..4e2f905 100644
--- a/Python/suggestions.c
+++ b/Python/suggestions.c
@@ -200,13 +200,21 @@ offer_suggestions_for_name_error(PyNameErrorObject *exc)
PyTracebackObject *traceback = (PyTracebackObject *) exc->traceback; // borrowed reference
// Abort if we don't have a variable name or we have an invalid one
// or if we don't have a traceback to work with
- if (name == NULL || traceback == NULL || !PyUnicode_CheckExact(name)) {
+ if (name == NULL || !PyUnicode_CheckExact(name) ||
+ traceback == NULL || !Py_IS_TYPE(traceback, &PyTraceBack_Type)
+ ) {
return NULL;
}
// Move to the traceback of the exception
- while (traceback->tb_next != NULL) {
- traceback = traceback->tb_next;
+ while (1) {
+ PyTracebackObject *next = traceback->tb_next;
+ if (next == NULL || !Py_IS_TYPE(next, &PyTraceBack_Type)) {
+ break;
+ }
+ else {
+ traceback = next;
+ }
}
PyFrameObject *frame = traceback->tb_frame;