From: Cristy <urban-warrior@imagemagick.org>
Date: Sat, 24 Feb 2018 14:35:38 +0000 (-0500)
Subject: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=6535
X-Git-Tag: 7.0.7-24~15
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=e79350c54735fd1051bd0b153ef277a13a7b9618;p=imagemagick

https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=6535
---

diff --git a/coders/dcm.c b/coders/dcm.c
index 1f66bba66..00d730485 100644
--- a/coders/dcm.c
+++ b/coders/dcm.c
@@ -3972,7 +3972,7 @@ static Image *ReadDCMImage(const ImageInfo *image_info,ExceptionInfo *exception)
           for (i=0; i < (ssize_t) colors; i++)
           {
             index=redmap[i];
-            if ((info.scale != (Quantum *) NULL) &&
+            if ((info.scale != (Quantum *) NULL) && (index >= 0) &&
                 (index <= (int) info.max_value))
               index=(int) info.scale[index];
             image->colormap[i].red=(MagickRealType) index;
@@ -3981,7 +3981,7 @@ static Image *ReadDCMImage(const ImageInfo *image_info,ExceptionInfo *exception)
           for (i=0; i < (ssize_t) colors; i++)
           {
             index=greenmap[i];
-            if ((info.scale != (Quantum *) NULL) &&
+            if ((info.scale != (Quantum *) NULL) && (index >= 0) &&
                 (index <= (int) info.max_value))
               index=(int) info.scale[index];
             image->colormap[i].green=(MagickRealType) index;
@@ -3990,7 +3990,7 @@ static Image *ReadDCMImage(const ImageInfo *image_info,ExceptionInfo *exception)
           for (i=0; i < (ssize_t) colors; i++)
           {
             index=bluemap[i];
-            if ((info.scale != (Quantum *) NULL) &&
+            if ((info.scale != (Quantum *) NULL) && (index >= 0) &&
                 (index <= (int) info.max_value))
               index=(int) info.scale[index];
             image->colormap[i].blue=(MagickRealType) index;
@@ -3999,7 +3999,7 @@ static Image *ReadDCMImage(const ImageInfo *image_info,ExceptionInfo *exception)
           for (i=0; i < (ssize_t) colors; i++)
           {
             index=graymap[i];
-            if ((info.scale != (Quantum *) NULL) &&
+            if ((info.scale != (Quantum *) NULL) && (index >= 0) &&
                 (index <= (int) info.max_value))
               index=(int) info.scale[index];
             image->colormap[i].red=(MagickRealType) index;