Eliminate buffer overwrite in DPX coder

Credit OSS Fuzz

diff --git a/MagickCore/quantum-import.c b/MagickCore/quantum-import.c
index 78282baa18d28c11a445e03a8a79c98c4fc1b444..c3d76321121e472465e1b3f2bf39317dd8f066e2 100644 (file)
--- a/MagickCore/quantum-import.c
+++ b/MagickCore/quantum-import.c
@@ -1421,7 +1421,7 @@ static void ImportCbYCrYQuantum(const Image *image,QuantumInfo *quantum_info,
 
           n=0;
           quantum=0;
-          for (x=0; x < (ssize_t) number_pixels; x+=4)
+          for (x=0; x < (ssize_t) (number_pixels-3); x+=4)
           {
             for (i=0; i < 4; i++)
             {