From: Cristy <urban-warrior@imagemagick.org>
Date: Tue, 23 Jan 2018 14:54:43 +0000 (-0500)
Subject: Eliminate invalid write
X-Git-Tag: 7.0.7-23~296
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=901c4bce459d42dd8e945c4b24f94fa885e1556c;p=imagemagick

Eliminate invalid write
Credit OSS Fuzz
---

diff --git a/MagickCore/quantum.c b/MagickCore/quantum.c
index ab7031685..c036a7777 100644
--- a/MagickCore/quantum.c
+++ b/MagickCore/quantum.c
@@ -689,7 +689,7 @@ MagickExport MagickBooleanType SetQuantumDepth(const Image *image,
   if (quantum_info->pixels != (MemoryInfo **) NULL)
     DestroyQuantumPixels(quantum_info);
   quantum=(quantum_info->pad+MaxPixelChannels)*(quantum_info->depth+7)/8;
-  extent=MagickMax(image->columns,image->rows)*quantum;
+  extent=4*MagickMax(image->columns,image->rows)*quantum;
   if ((MagickMax(image->columns,image->rows) != 0) &&
       (quantum != (extent/MagickMax(image->columns,image->rows))))
     return(MagickFalse);