commit 19eb87d857f6d1bad1a3619d9d7534820f82e5f2
author Serhiy Storchaka <storchaka@gmail.com> Tue Sep 26 09:11:27 2017 +0300
committer GitHub <noreply@github.com> Tue Sep 26 09:11:27 2017 +0300
tree 6413d3c18f9a48c7bd0efa9e401a4dc8bbb5f7de
parent d94a65a0694a188713f91ba7c9fffded090247dc

[2.7] bpo-31579: Fixed a possible leak in enumerate() with large indices. (GH-3753). (#3761)

(cherry picked from commit 0e950dd22b075b4809c84afda8aede02b76ac0fa)

Objects/enumobject.c

diff --git a/Objects/enumobject.c b/Objects/enumobject.c
index 1ef381f..8f86a5b 100644
--- a/Objects/enumobject.c
+++ b/Objects/enumobject.c
@@ -87,19 +87,25 @@
 
     if (en->en_longindex == NULL) {
         en->en_longindex = PyInt_FromSsize_t(PY_SSIZE_T_MAX);
-        if (en->en_longindex == NULL)
+        if (en->en_longindex == NULL) {
+            Py_DECREF(next_item);
             return NULL;
+        }
     }
     if (one == NULL) {
         one = PyInt_FromLong(1);
-        if (one == NULL)
+        if (one == NULL) {
+            Py_DECREF(next_item);
             return NULL;
+        }
     }
     next_index = en->en_longindex;
     assert(next_index != NULL);
     stepped_up = PyNumber_Add(next_index, one);
-    if (stepped_up == NULL)
+    if (stepped_up == NULL) {
+        Py_DECREF(next_item);
         return NULL;
+    }
     en->en_longindex = stepped_up;
 
     if (result->ob_refcnt == 1) {