From 0fba9b324f061a4c8af9f39c3d0befdf29e2a216 Mon Sep 17 00:00:00 2001
From: Steve Dower <steve.dower@microsoft.com>
Date: Sat, 5 Sep 2015 20:55:34 -0700
Subject: [PATCH] Issue #24917: time_strftime() Buffer Over-read. Patch by John
 Leitch.

---
 Misc/NEWS            | 2 ++
 Modules/timemodule.c | 6 ++++++
 2 files changed, 8 insertions(+)

diff --git a/Misc/NEWS b/Misc/NEWS
index dd175fead46..834e20a8158 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -84,6 +84,8 @@ Library
 - Issue #16180: Exit pdb if file has syntax error, instead of trapping user
   in an infinite loop.  Patch by Xavier de Gaye.
 
+- Issue #24917: time_strftime() Buffer Over-read. Patch by John Leitch.
+
 - Issue #21112: Fix regression in unittest.expectedFailure on subclasses.
   Patch from Berker Peksag.
 
diff --git a/Modules/timemodule.c b/Modules/timemodule.c
index d0917a40730..f7295946917 100644
--- a/Modules/timemodule.c
+++ b/Modules/timemodule.c
@@ -662,6 +662,12 @@ time_strftime(PyObject *self, PyObject *args)
                             "format %y requires year >= 1900 on AIX");
             return NULL;
         }
+        else if (outbuf[1] == '\0')
+        {
+            PyErr_SetString(PyExc_ValueError, "Incomplete format string");
+            Py_DECREF(format);
+            return NULL;
+        }
     }
 #endif