[release/2.1] Tiff decoding robustness improvements (#2550)

src/ImageSharp/Compression/Zlib/ZlibInflateStream.cs

@@ -161,29 +161,25 @@ public override int Read(byte[] buffer, int offset, int count)
                 bytesToRead = Math.Min(count - totalBytesRead, this.currentDataRemaining);
                 this.currentDataRemaining -= bytesToRead;
                 bytesRead = this.innerStream.Read(buffer, offset, bytesToRead);
+                if (bytesRead == 0)
+                {
+                    return totalBytesRead;
+                }
+
                 totalBytesRead += bytesRead;
             }
 
             return totalBytesRead;
         }
 
         /// <inheritdoc/>
-        public override long Seek(long offset, SeekOrigin origin)
-        {
-            throw new NotSupportedException();
-        }
+        public override long Seek(long offset, SeekOrigin origin) => throw new NotSupportedException();
 
         /// <inheritdoc/>
-        public override void SetLength(long value)
-        {
-            throw new NotSupportedException();
-        }
+        public override void SetLength(long value) => throw new NotSupportedException();
 
         /// <inheritdoc/>
-        public override void Write(byte[] buffer, int offset, int count)
-        {
-            throw new NotSupportedException();
-        }
+        public override void Write(byte[] buffer, int offset, int count) => throw new NotSupportedException();
 
         /// <inheritdoc/>
         protected override void Dispose(bool disposing)
@@ -245,22 +241,17 @@ private bool InitializeInflateStream(bool isCriticalChunk)
                         // CINFO is not defined in this specification for CM not equal to 8.
                         throw new ImageFormatException($"Invalid window size for ZLIB header: cinfo={cinfo}");
                     }
-                    else
-                    {
-                        return false;
-                    }
+
+                    return false;
                 }
             }
+            else if (isCriticalChunk)
+            {
+                throw new ImageFormatException($"Bad method for ZLIB header: cmf={cmf}");
+            }
             else
             {
-                if (isCriticalChunk)
-                {
-                    throw new ImageFormatException($"Bad method for ZLIB header: cmf={cmf}");
-                }
-                else
-                {
-                    return false;
-                }
+                return false;
             }
 
             // The preset dictionary.
@@ -269,7 +260,11 @@ private bool InitializeInflateStream(bool isCriticalChunk)
             {
                 // We don't need this for inflate so simply skip by the next four bytes.
                 // https://tools.ietf.org/html/rfc1950#page-6
-                this.innerStream.Read(ChecksumBuffer, 0, 4);
+                if (this.innerStream.Read(ChecksumBuffer, 0, 4) != 4)
+                {
+                    return false;
+                }
+
                 this.currentDataRemaining -= 4;
             }
 

src/ImageSharp/Formats/Tiff/Ifd/DirectoryReader.cs

@@ -43,7 +43,7 @@ public DirectoryReader(Stream stream, MemoryAllocator allocator)
         public IEnumerable<ExifProfile> Read()
         {
             this.ByteOrder = ReadByteOrder(this.stream);
-            var headerReader = new HeaderReader(this.stream, this.ByteOrder);
+            HeaderReader headerReader = new(this.stream, this.ByteOrder);
             headerReader.ReadFileHeader();
 
             this.nextIfdOffset = headerReader.FirstIfdOffset;
@@ -55,7 +55,12 @@ public IEnumerable<ExifProfile> Read()
         private static ByteOrder ReadByteOrder(Stream stream)
         {
             Span<byte> headerBytes = stackalloc byte[2];
-            stream.Read(headerBytes);
+
+            if (stream.Read(headerBytes) != 2)
+            {
+                throw TiffThrowHelper.ThrowInvalidHeader();
+            }
+
             if (headerBytes[0] == TiffConstants.ByteOrderLittleEndian && headerBytes[1] == TiffConstants.ByteOrderLittleEndian)
             {
                 return ByteOrder.LittleEndian;
@@ -74,7 +79,7 @@ private IEnumerable<ExifProfile> ReadIfds(bool isBigTiff)
             var readers = new List<EntryReader>();
             while (this.nextIfdOffset != 0 && this.nextIfdOffset < (ulong)this.stream.Length)
             {
-                var reader = new EntryReader(this.stream, this.ByteOrder, this.allocator);
+                EntryReader reader = new(this.stream, this.ByteOrder, this.allocator);
                 reader.ReadTags(isBigTiff, this.nextIfdOffset);
 
                 if (reader.BigValues.Count > 0)
@@ -88,6 +93,11 @@ private IEnumerable<ExifProfile> ReadIfds(bool isBigTiff)
                     }
                 }
 
+                if (this.nextIfdOffset >= reader.NextIfdOffset && reader.NextIfdOffset != 0)
+                {
+                    TiffThrowHelper.ThrowImageFormatException("TIFF image contains circular directory offsets");
+                }
+
                 this.nextIfdOffset = reader.NextIfdOffset;
                 readers.Add(reader);
 

tests/ImageSharp.Tests/Formats/Tiff/TiffDecoderTests.cs

@@ -274,7 +274,7 @@
 
         [Theory]
         [WithFile(Rgba6BitAssociatedAlpha, PixelTypes.Rgba32)]
         public void TiffDecoder_CanDecode_24Bit_WithAssociatedAlpha<TPixel>(TestImageProvider<TPixel> provider)            
             where TPixel : unmanaged, IPixel<TPixel>
         {
             if (TestEnvironment.IsMacOS)
@@ -668,6 +668,18 @@
                     }
                 });
 
+        [Theory]
+        [WithFile(JpegCompressedGray0000539558, PixelTypes.Rgba32)]
+        public void TiffDecoder_ThrowsException_WithCircular_IFD_Offsets<TPixel>(TestImageProvider<TPixel> provider)
+            where TPixel : unmanaged, IPixel<TPixel>
+            => Assert.Throws<ImageFormatException>(
+                () =>
+                {
+                    using (provider.GetImage(TiffDecoder))
+                    {
+                    }
+                });
+
         [Theory]
         [WithFileCollection(nameof(MultiframeTestImages), PixelTypes.Rgba32)]
         public void DecodeMultiframe<TPixel>(TestImageProvider<TPixel> provider)

tests/ImageSharp.Tests/TestImages.cs

@@ -916,6 +916,7 @@ public static class Tiff
             public const string Issues1716Rgb161616BitLittleEndian = "Tiff/Issues/Issue1716.tiff";
             public const string Issues1891 = "Tiff/Issues/Issue1891.tiff";
             public const string Issues2123 = "Tiff/Issues/Issue2123.tiff";
+            public const string JpegCompressedGray0000539558 = "Tiff/Issues/JpegCompressedGray-0000539558.tiff";
 
             public const string SmallRgbDeflate = "Tiff/rgb_small_deflate.tiff";
             public const string SmallRgbLzw = "Tiff/rgb_small_lzw.tiff";