File GraphicsMagick-CVE-2017-6335.patch of Package GraphicsMagick.7727

--- a/coders/tiff.c
+++ b/coders/tiff.c
@@ -1411,12 +1411,12 @@
               }
             else
               {
-                if (image->matte)
+                if (image->matte && samples_per_pixel >= 5)
                   {
                     *quantum_type=CMYKAQuantum;
                     *quantum_samples=5;
                   }
-                else
+                else if (samples_per_pixel >= 4)
                   {
                     *quantum_type=CMYKQuantum;
                     *quantum_samples=4;