From 853e72d58e2c202a6bc2a25eefb6eae9cb273538 Mon Sep 17 00:00:00 2001
From: erouault <erouault>
Date: Mon, 23 Oct 2017 11:34:26 +0000
Subject: * libtiff/tif_getimage.c: avoid floating point division by zero in
 initCIELabConversion() Fixes
 https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=3733 Credit to OSS Fuzz

---
 ChangeLog              |  7 +++++++
 libtiff/tif_getimage.c | 10 ++++++++--
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 02873f2b..797b2317 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2017-10-23  Even Rouault <even.rouault at spatialys.com>
+
+	* libtiff/tif_getimage.c: avoid floating point division by zero in
+	initCIELabConversion()
+	Fixes https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=3733
+	Credit to OSS Fuzz
+
 2017-10-17  Even Rouault <even.rouault at spatialys.com>
 
 	* libtiff/tif_jpeg.c: add compatibility with libjpeg-turbo 1.5.2 that
diff --git a/libtiff/tif_getimage.c b/libtiff/tif_getimage.c
index c51c8894..032d2781 100644
--- a/libtiff/tif_getimage.c
+++ b/libtiff/tif_getimage.c
@@ -1,4 +1,4 @@
-/* $Id: tif_getimage.c,v 1.112 2017-07-24 10:34:14 erouault Exp $ */
+/* $Id: tif_getimage.c,v 1.113 2017-10-23 11:34:26 erouault Exp $ */
 
 /*
  * Copyright (c) 1991-1997 Sam Leffler
@@ -2332,6 +2332,13 @@ initCIELabConversion(TIFFRGBAImage* img)
 	float   *whitePoint;
 	float   refWhite[3];
 
+	TIFFGetFieldDefaulted(img->tif, TIFFTAG_WHITEPOINT, &whitePoint);
+	if (whitePoint[1] == 0.0f ) {
+		TIFFErrorExt(img->tif->tif_clientdata, module,
+		    "Invalid value for WhitePoint tag.");
+		return NULL;
+        }
+
 	if (!img->cielab) {
 		img->cielab = (TIFFCIELabToRGB *)
 			_TIFFmalloc(sizeof(TIFFCIELabToRGB));
@@ -2342,7 +2349,6 @@ initCIELabConversion(TIFFRGBAImage* img)
 		}
 	}
 
-	TIFFGetFieldDefaulted(img->tif, TIFFTAG_WHITEPOINT, &whitePoint);
 	refWhite[1] = 100.0F;
 	refWhite[0] = whitePoint[0] / whitePoint[1] * refWhite[1];
 	refWhite[2] = (1.0F - whitePoint[0] - whitePoint[1])
-- 
cgit v1.2.1