From: Christian Heimes <christian@python.org>
Date: Thu, 8 Sep 2016 22:22:28 +0000 (+0200)
Subject: Fix potential NULL pointer dereference in update_symbols()
X-Git-Tag: v3.6.0b1~235
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=45af0c83da093ac8f6756d98c36e064e7c01b19b;p=thirdparty%2FPython%2Fcpython.git

Fix potential NULL pointer dereference in update_symbols()

symtable_analyze() calls analyze_block() with bound=NULL. Theoretically
that NULL can be passed down to update_symbols(). update_symbols() may
deference NULL and pass it to PySet_Contains()
---

diff --git a/Python/symtable.c b/Python/symtable.c
index 3f03184f088a..45a8c2c64bd9 100644
--- a/Python/symtable.c
+++ b/Python/symtable.c
@@ -652,7 +652,7 @@ update_symbols(PyObject *symbols, PyObject *scopes,
             continue;
         }
         /* Handle global symbol */
-        if (!PySet_Contains(bound, name)) {
+        if (bound && !PySet_Contains(bound, name)) {
             Py_DECREF(name);
             continue;       /* it's a global */
         }