From 37516fb665c2c9f99ba0681a25fa3e2b1caf7deb Mon Sep 17 00:00:00 2001
From: Jayakrishna Menon <jkrshnmenon@gmail.com>
Date: Fri, 8 Mar 2019 11:30:35 -0700
Subject: [PATCH] adding an upper limit for blocks_max in _set_blocks_max

---
 src/_imaging.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/_imaging.c b/src/_imaging.c
index 1391ffae6..dffef3689 100644
--- a/src/_imaging.c
+++ b/src/_imaging.c
@@ -3625,6 +3625,12 @@ _set_blocks_max(PyObject* self, PyObject* args)
             "blocks_max should be greater than 0");
         return NULL;
     }
+    else if ( blocks_max > SIZE_MAX/sizeof(ImagingDefaultArena.blocks_pool[0])) {
+        PyErr_SetString(PyExc_ValueError,
+            "blocks_max is too large");
+        return NULL;
+    }
+
 
     if ( ! ImagingMemorySetBlocksMax(&ImagingDefaultArena, blocks_max)) {
         ImagingError_MemoryError();