[Python-checkins] bpo-30640: Fix undefined behavior in _PyFunction_FastCallDict() and PyEval_EvalCodeEx() (#2919)

[Serhiy Storchaka]

https://github.com/python/cpython/commit/c6ea8974e2d939223bfd6d64ee13ec89c090d2e0
commit: c6ea8974e2d939223bfd6d64ee13ec89c090d2e0
branch: master
author: Zackery Spytz <Osmunda46 at gmail.com>
committer: Serhiy Storchaka <storchaka at gmail.com>
date: 2017-07-31T17:24:37+03:00
summary:

bpo-30640: Fix undefined behavior in _PyFunction_FastCallDict() and PyEval_EvalCodeEx() (#2919)

k + 1 was calculated with k = NULL.

files:
M Objects/call.c
M Python/ceval.c

diff --git a/Objects/call.c b/Objects/call.c
index c3cc31dba9b..3b08cb25926 100644
--- a/Objects/call.c
+++ b/Objects/call.c
@@ -374,7 +374,7 @@ _PyFunction_FastCallDict(PyObject *func, PyObject **args, Py_ssize_t nargs,
 
     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);
diff --git a/Python/ceval.c b/Python/ceval.c
index 59fc070f9e7..dd90e18a855 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -4220,7 +4220,8 @@ PyEval_EvalCodeEx(PyObject *_co, PyObject *globals, PyObject *locals,
 {
     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);