From 1f9531764cc0f8dbca1d8f429d162dc28282f4b4 Mon Sep 17 00:00:00 2001 From: Jeroen Demeyer Date: Fri, 7 Jun 2019 20:01:53 +0200 Subject: bpo-37138: fix undefined behaviour with memcpy() on NULL array (GH-13867) --- Objects/classobject.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/Objects/classobject.c b/Objects/classobject.c index ffd3f87..2415ed1 100644 --- a/Objects/classobject.c +++ b/Objects/classobject.c @@ -71,7 +71,11 @@ method_vectorcall(PyObject *method, PyObject *const *args, } /* use borrowed references */ newargs[0] = self; - memcpy(newargs + 1, args, totalargs * sizeof(PyObject *)); + if (totalargs) { /* bpo-37138: if totalargs == 0, then args may be + * NULL and calling memcpy() with a NULL pointer + * is undefined behaviour. */ + memcpy(newargs + 1, args, totalargs * sizeof(PyObject *)); + } result = _PyObject_Vectorcall(func, newargs, nargs+1, kwnames); PyMem_Free(newargs); } -- cgit v0.12