Closes release blocker #3627.

Merged revisions 65335 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk

TESTED=./python -E -tt ./Lib/test/regrtest.py -uall (both debug and opt)

........
  r65335 | neal.norwitz | 2008-07-31 10:17:14 -0700 (Thu, 31 Jul 2008) | 1 line

  Security patches from Apple:  prevent int overflow when allocating memory
........
diff --git a/Modules/gcmodule.c b/Modules/gcmodule.c
index 51bcd79f..f7eef4d 100644
--- a/Modules/gcmodule.c
+++ b/Modules/gcmodule.c
@@ -1318,7 +1318,10 @@
 _PyObject_GC_Malloc(size_t basicsize)
 {
 	PyObject *op;
-	PyGC_Head *g = (PyGC_Head *)PyObject_MALLOC(
+	PyGC_Head *g;
+	if (basicsize > PY_SSIZE_T_MAX - sizeof(PyGC_Head))
+		return PyErr_NoMemory();
+	g = (PyGC_Head *)PyObject_MALLOC(
                 sizeof(PyGC_Head) + basicsize);
 	if (g == NULL)
 		return PyErr_NoMemory();
@@ -1361,6 +1364,8 @@
 {
 	const size_t basicsize = _PyObject_VAR_SIZE(Py_TYPE(op), nitems);
 	PyGC_Head *g = AS_GC(op);
+	if (basicsize > PY_SSIZE_T_MAX - sizeof(PyGC_Head))
+		return (PyVarObject *)PyErr_NoMemory();
 	g = (PyGC_Head *)PyObject_REALLOC(g,  sizeof(PyGC_Head) + basicsize);
 	if (g == NULL)
 		return (PyVarObject *)PyErr_NoMemory();