Better PNG chunk length error message

Via drewnoakes/metadata-extractor#272
drewnoakes · Nov 24, 2017 · 35f7a90 · 35f7a90
1 parent ce4479f
commit 35f7a90
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/MetadataExtractor/Formats/Png/PngChunkReader.cs b/MetadataExtractor/Formats/Png/PngChunkReader.cs
@@ -88,6 +88,8 @@ public IEnumerable<PngChunk> Extract([NotNull] SequentialReader reader, [CanBeNu
             {
                 // Process the next chunk.
                 var chunkDataLength = reader.GetInt32();
+                if (chunkDataLength < 0)
+                    throw new PngProcessingException("PNG chunk length exceeds maximum");
                 var chunkType = new PngChunkType(reader.GetBytes(4));
                 var willStoreChunk = desiredChunkTypes == null || desiredChunkTypes.Contains(chunkType);
                 var chunkData = reader.GetBytes(chunkDataLength);