static MagickBooleanType ReadPSDChannelPixels(Image *image,
  const size_t channels,const size_t row,const ssize_t type,
  const unsigned char *pixels,ExceptionInfo *exception)
{
  Quantum
    pixel;

  register const unsigned char
    *p;

  register Quantum
    *q;

  register ssize_t
    x;

  size_t
    packet_size;

  unsigned short
    nibble;

  p=pixels;
  q=GetAuthenticPixels(image,0,row,image->columns,1,exception);
  if (q == (Quantum *) NULL)
    return MagickFalse;
  packet_size=GetPSDPacketSize(image);
  for (x=0; x < (ssize_t) image->columns; x++)
  {
    if (packet_size == 1)
      pixel=ScaleCharToQuantum(*p++);
    else
      {
        p=PushShortPixel(MSBEndian,p,&nibble);
        pixel=ScaleShortToQuantum(nibble);
      }
    if (image->depth > 1)
      {
        SetPSDPixel(image,channels,type,packet_size,pixel,q,exception);
        q+=GetPixelChannels(image);
      }
    else
      {
        ssize_t
          bit,
          number_bits;
      
        number_bits=image->columns-x;
        if (number_bits > 8)
          number_bits=8;
        for (bit = 0; bit < number_bits; bit++)
        {
          SetPSDPixel(image,channels,type,packet_size,(((unsigned char) pixel)
            & (0x01 << (7-bit))) != 0 ? 0 : QuantumRange,q,exception);
          q+=GetPixelChannels(image);
          x++;
        }
        if (x != (ssize_t) image->columns)
          x--;
        continue;
      }
  }
  return(SyncAuthenticPixels(image,exception));
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.