https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=44424

ImageMagick · Feb 5, 2022 · bbf05a3 · bbf05a3
1 parent fa0b758
commit bbf05a3
Showing 1 changed file with 20 additions and 6 deletions.
diff --git a/coders/png.c b/coders/png.c
@@ -4914,26 +4914,40 @@ static Image *ReadOneJNGImage(MngInfo *mng_info,
   if ((image_info->ping == MagickFalse) && (alpha_image != (Image *) NULL) &&
       (jng_color_type >= 12))
     {
-      if (jng_alpha_compression_method == 0)
+      switch (jng_alpha_compression_method)
+      {
+        case 0:
         {
           png_byte
             data[5];
+
+          (void) FormatLocaleString(alpha_image_info->filename,MagickPathExtent,
+            "png:%s",alpha_image->filename);
           (void) WriteBlobMSBULong(alpha_image,0x00000000L);
           PNGType(data,mng_IEND);
           LogPNGChunk(logging,mng_IEND,0L);
           (void) WriteBlob(alpha_image,4,data);
           (void) WriteBlobMSBULong(alpha_image,crc32(0,data,4));
+          break;
         }
-
+        case 8:
+        {
+          (void) FormatLocaleString(alpha_image_info->filename,MagickPathExtent,
+            "jpeg:%s",alpha_image->filename);
+          break;
+        }
+        default:
+        {
+          (void) FormatLocaleString(alpha_image_info->filename,MagickPathExtent,
+            "alpha:%s",alpha_image->filename);
+          break;
+        }
+      }
       (void) CloseBlob(alpha_image);
 
       if (logging != MagickFalse)
         (void) LogMagickEvent(CoderEvent,GetMagickModule(),
           "    Reading opacity from alpha_blob.");
-
-      (void) FormatLocaleString(alpha_image_info->filename,MaxTextExtent,
-        "%s",alpha_image->filename);
-
       jng_image=ReadImage(alpha_image_info,exception);
 
       if (jng_image != (Image *) NULL)