* tools/tiffcrop.c: Avoid access outside of stack allocated array

on a tiled separate TIFF with more than 8 samples per pixel.
Reported by Kaixiang Zhang of the Cloud Security Team, Qihoo 360
(CVE-2016-5321, bugzilla #2558)

ChangeLog

@@ -1,3 +1,10 @@
+2016-07-11 Even Rouault <even.rouault at spatialys.com>
+
+	* tools/tiffcrop.c: Avoid access outside of stack allocated array
+	on a tiled separate TIFF with more than 8 samples per pixel.
+	Reported by Kaixiang Zhang of the Cloud Security Team, Qihoo 360
+	(CVE-2016-5321, bugzilla #2558)
+
 2016-07-10 Even Rouault <even.rouault at spatialys.com>
 
 	* libtiff/tif_read.c: Fix out-of-bounds read on

tools/tiffcrop.c

@@ -989,7 +989,7 @@ static int  readSeparateTilesIntoBuffer (TIFF* in, uint8 *obuf,
     nrow = (row + tl > imagelength) ? imagelength - row : tl;
     for (col = 0; col < imagewidth; col += tw)
       {
-      for (s = 0; s < spp; s++)
+      for (s = 0; s < spp && s < MAX_SAMPLES; s++)
         {  /* Read each plane of a tile set into srcbuffs[s] */
 	tbytes = TIFFReadTile(in, srcbuffs[s], col, row, 0, s);
         if (tbytes < 0  && !ignore)