Mercurial > cpython-lru_cache-weakref

diff Objects/tupleobject.c @ 79529:152d85b2da3a 3.3

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Issue #16096: Fix several occurrences of potential signed integer overflow. Thanks Serhiy Storchaka.
author Mark Dickinson <mdickinson@enthought.com>
date Sat, 06 Oct 2012 18:04:49 +0100
parents 033b409f7cd6
children 8b4fff41dee5
line wrap: on
line diff
--- a/Objects/tupleobject.c	Sat Oct 06 18:45:47 2012 +0300
+++ b/Objects/tupleobject.c	Sat Oct 06 18:04:49 2012 +0100
@@ -96,15 +96,11 @@
     else
 #endif
     {
-        Py_ssize_t nbytes = size * sizeof(PyObject *);
         /* Check for overflow */
-        if (nbytes / sizeof(PyObject *) != (size_t)size ||
-            (nbytes > PY_SSIZE_T_MAX - sizeof(PyTupleObject) - sizeof(PyObject *)))
-        {
+        if (size > (PY_SSIZE_T_MAX - sizeof(PyTupleObject) -
+                    sizeof(PyObject *)) / sizeof(PyObject *)) {
             return PyErr_NoMemory();
         }
-        /* nbytes += sizeof(PyTupleObject) - sizeof(PyObject *); */
-
         op = PyObject_GC_NewVar(PyTupleObject, &PyTuple_Type, size);
         if (op == NULL)
             return NULL;
@@ -481,9 +477,9 @@
         if (Py_SIZE(a) == 0)
             return PyTuple_New(0);
     }
+    if (n > PY_SSIZE_T_MAX / Py_SIZE(a))
+        return PyErr_NoMemory();
     size = Py_SIZE(a) * n;
-    if (size/Py_SIZE(a) != n)
-        return PyErr_NoMemory();
     np = (PyTupleObject *) PyTuple_New(size);
     if (np == NULL)
         return NULL;