From 8e1d3a2d41b6f064b60e69b3432ed3a2692bd19f Mon Sep 17 00:00:00 2001
From: Alexander Belopolsky <alexander.belopolsky@gmail.com>
Date: Mon, 25 Jul 2016 13:54:51 -0400
Subject: [PATCH] Issue 24773: Added a time_t overflow check.

---
 Modules/_datetimemodule.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/Modules/_datetimemodule.c b/Modules/_datetimemodule.c
index 1157859ae3f..7dfb0c2684b 100644
--- a/Modules/_datetimemodule.c
+++ b/Modules/_datetimemodule.c
@@ -4207,7 +4207,14 @@ static PY_LONG_LONG
 local(PY_LONG_LONG u)
 {
     struct tm local_time;
-    time_t t = u - epoch;
+    time_t t;
+    u -= epoch;
+    t = u;
+    if (t != u) {
+        PyErr_SetString(PyExc_OverflowError,
+        "timestamp out of range for platform time_t");
+        return -1;
+    }
     /* XXX: add bounds checking */
     if (localtime_r(&t, &local_time) == NULL) {
         PyErr_SetFromErrno(PyExc_OSError);