Restrict co_code to be under INT_MAX in codeobject (GH-20628)
diff --git a/Objects/codeobject.c b/Objects/codeobject.c
index 7376359..cb4fb68 100644
--- a/Objects/codeobject.c
+++ b/Objects/codeobject.c
@@ -166,6 +166,14 @@
return NULL;
}
+ /* Make sure that code is indexable with an int, this is
+ a long running assumption in ceval.c and many parts of
+ the interpreter. */
+ if (PyBytes_GET_SIZE(code) > INT_MAX) {
+ PyErr_SetString(PyExc_OverflowError, "co_code larger than INT_MAX");
+ return NULL;
+ }
+
/* Check for any inner or outer closure references */
n_cellvars = PyTuple_GET_SIZE(cellvars);
if (!n_cellvars && !PyTuple_GET_SIZE(freevars)) {
diff --git a/Objects/frameobject.c b/Objects/frameobject.c
index 0dad42e..6e1cbcf 100644
--- a/Objects/frameobject.c
+++ b/Objects/frameobject.c
@@ -397,9 +397,9 @@
return -1;
}
- int len = Py_SAFE_DOWNCAST(
- PyBytes_GET_SIZE(f->f_code->co_code)/sizeof(_Py_CODEUNIT),
- Py_ssize_t, int);
+ /* PyCode_NewWithPosOnlyArgs limits co_code to be under INT_MAX so this
+ * should never overflow. */
+ int len = (int)(PyBytes_GET_SIZE(f->f_code->co_code) / sizeof(_Py_CODEUNIT));
int *lines = marklines(f->f_code, len);
if (lines == NULL) {
return -1;