static MagickBooleanType WriteGROUP4Image(const ImageInfo *image_info,
  Image *image,ExceptionInfo *exception)
{
  char
    filename[MagickPathExtent];

  FILE
    *file;

  Image
    *huffman_image;

  ImageInfo
    *write_info;

  int
    unique_file;

  MagickBooleanType
    status;

  register ssize_t
    i;

  ssize_t
    count;

  TIFF
    *tiff;

  toff_t
    *byte_count,
    strip_size;

  unsigned char
    *buffer;

  /*
    Write image as CCITT Group4 TIFF image to a temporary file.
  */
  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickCoreSignature);
  assert(image != (Image *) NULL);
  assert(image->signature == MagickCoreSignature);
  if (image->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
  assert(exception != (ExceptionInfo *) NULL);
  assert(exception->signature == MagickCoreSignature);
  status=OpenBlob(image_info,image,WriteBinaryBlobMode,exception);
  if (status == MagickFalse)
    return(status);
  huffman_image=CloneImage(image,0,0,MagickTrue,exception);
  if (huffman_image == (Image *) NULL)
    {
      (void) CloseBlob(image);
      return(MagickFalse);
    }
  huffman_image->endian=MSBEndian;
  file=(FILE *) NULL;
  unique_file=AcquireUniqueFileResource(filename);
  if (unique_file != -1)
    file=fdopen(unique_file,"wb");
  if ((unique_file == -1) || (file == (FILE *) NULL))
    {
      ThrowFileException(exception,FileOpenError,"UnableToCreateTemporaryFile",
        filename);
      return(MagickFalse);
    }
  (void) FormatLocaleString(huffman_image->filename,MagickPathExtent,"tiff:%s",
    filename);
  (void) SetImageType(huffman_image,BilevelType,exception);
  write_info=CloneImageInfo((ImageInfo *) NULL);
  SetImageInfoFile(write_info,file);
  (void) SetImageDepth(image,1,exception);
  (void) SetImageType(image,BilevelType,exception);
  write_info->compression=Group4Compression;
  write_info->type=BilevelType;
  status=WriteTIFFImage(write_info,huffman_image,exception);
  (void) fflush(file);
  write_info=DestroyImageInfo(write_info);
  if (status == MagickFalse)
    {
      huffman_image=DestroyImage(huffman_image);
      (void) fclose(file);
      (void) RelinquishUniqueFileResource(filename);
      return(MagickFalse);
    }
  tiff=TIFFOpen(filename,"rb");
  if (tiff == (TIFF *) NULL)
    {
      huffman_image=DestroyImage(huffman_image);
      (void) fclose(file);
      (void) RelinquishUniqueFileResource(filename);
      ThrowFileException(exception,FileOpenError,"UnableToOpenFile",
        image_info->filename);
      return(MagickFalse);
    }
  /*
    Allocate raw strip buffer.
  */
  if (TIFFGetField(tiff,TIFFTAG_STRIPBYTECOUNTS,&byte_count) != 1)
    {
      TIFFClose(tiff);
      huffman_image=DestroyImage(huffman_image);
      (void) fclose(file);
      (void) RelinquishUniqueFileResource(filename);
      return(MagickFalse);
    }
  strip_size=byte_count[0];
  for (i=1; i < (ssize_t) TIFFNumberOfStrips(tiff); i++)
    if (byte_count[i] > strip_size)
      strip_size=byte_count[i];
  buffer=(unsigned char *) AcquireQuantumMemory((size_t) strip_size,
    sizeof(*buffer));
  if (buffer == (unsigned char *) NULL)
    {
      TIFFClose(tiff);
      huffman_image=DestroyImage(huffman_image);
      (void) fclose(file);
      (void) RelinquishUniqueFileResource(filename);
      ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
        image_info->filename);
    }
  /*
    Compress runlength encoded to 2D Huffman pixels.
  */
  for (i=0; i < (ssize_t) TIFFNumberOfStrips(tiff); i++)
  {
    count=(ssize_t) TIFFReadRawStrip(tiff,(uint32) i,buffer,strip_size);
    if (WriteBlob(image,(size_t) count,buffer) != count)
      status=MagickFalse;
  }
  buffer=(unsigned char *) RelinquishMagickMemory(buffer);
  TIFFClose(tiff);
  huffman_image=DestroyImage(huffman_image);
  (void) fclose(file);
  (void) RelinquishUniqueFileResource(filename);
  (void) CloseBlob(image);
  return(status);
}

The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.