commit f032e9237aa7d43d21e0b04d685c36bddf7078c1
author Zackery Spytz <Osmunda46@gmail.com> Thu Sep 07 19:17:38 2017 -0600
committer Victor Stinner <victor.stinner@gmail.com> Fri Sep 08 03:17:38 2017 +0200
tree 230e38007523d7183966abc26d4a147a1de4928d
parent 645c1e421348790d49eab863279a41cb2b6a007a

[3.6] bpo-30640: Fix undefined behavior in _PyFunction_FastCallDict() and PyEval_EvalCodeEx() (GH-2919) (#2964)

k + 1 was calculated with k = NULL..
(cherry picked from commit c6ea8974e2d939223bfd6d64ee13ec89c090d2e0)

Python/ceval.c

diff --git a/Python/ceval.c b/Python/ceval.c
index 8eb78bf..4aa3250 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -4171,7 +4171,8 @@
 {
     return _PyEval_EvalCodeWithName(_co, globals, locals,
                                     args, argcount,
-                                    kws, kws + 1, kwcount, 2,
+                                    kws, kws != NULL ? kws + 1 : NULL,
+                                    kwcount, 2,
                                     defs, defcount,
                                     kwdefs, closure,
                                     NULL, NULL);
@@ -5053,7 +5054,7 @@
 
     result = _PyEval_EvalCodeWithName((PyObject*)co, globals, (PyObject *)NULL,
                                       args, nargs,
-                                      k, k + 1, nk, 2,
+                                      k, k != NULL ? k + 1 : NULL, nk, 2,
                                       d, nd, kwdefs,
                                       closure, name, qualname);
     Py_XDECREF(kwtuple);