Commit message: Reset memory for RLE decoder (patch provided by scarybeasts)
CVE: CVE-2017-9098
CWE: CWE-200
Vulnerability description: ImageMagick before 7.0.5-2 and GraphicsMagick before 1.3.24 use uninitialized memory in the RLE decoder, allowing an attacker to leak sensitive information from process memory space, as demonstrated by remote attacks against ImageMagick code in a long-running server process that converts image data on behalf of multiple users. This is caused by a missing initialization step in the ReadRLEImage function in coders/rle.c.

Project: ImageMagick
File: rle.c

static Image *ReadRLEImage(const ImageInfo *image_info,ExceptionInfo *exception)
{
#define SkipLinesOp  0x01
#define SetColorOp  0x02
#define SkipPixelsOp  0x03
#define ByteDataOp  0x05
#define RunDataOp  0x06
#define EOFOp  0x07

  char
    magick[12];

  Image
    *image;

  int
    opcode,
    operand,
    status;

  MagickStatusType
    flags;

  MagickSizeType
    number_pixels;

  MemoryInfo
    *pixel_info;

  Quantum
    index;

  register ssize_t
    x;

  register Quantum
    *q;

  register ssize_t
    i;

  register unsigned char
    *p;

  size_t
    bits_per_pixel,
    map_length,
    number_colormaps,
    number_planes,
    number_planes_filled,
    one,
    pixel_info_length;

  ssize_t
    count,
    offset,
    y;

  unsigned char
    background_color[256],
    *colormap,
    pixel,
    plane,
    *pixels;

  /*
    Open image file.
  */
  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickCoreSignature);
  if (image_info->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",
      image_info->filename);
  assert(exception != (ExceptionInfo *) NULL);
  assert(exception->signature == MagickCoreSignature);
  image=AcquireImage(image_info,exception);
  status=OpenBlob(image_info,image,ReadBinaryBlobMode,exception);
  if (status == MagickFalse)
    return(DestroyImageList(image));
  /*
    Determine if this a RLE file.
  */
  count=ReadBlob(image,2,(unsigned char *) magick);
  if ((count != 2) || (memcmp(magick,"\122\314",2) != 0))
    ThrowReaderException(CorruptImageError,"ImproperImageHeader");
  do
  {
    /*
      Read image header.
    */
    image->page.x=ReadBlobLSBShort(image);
    image->page.y=ReadBlobLSBShort(image);
    image->columns=ReadBlobLSBShort(image);
    image->rows=ReadBlobLSBShort(image);
    flags=(MagickStatusType) ReadBlobByte(image);
    image->alpha_trait=flags & 0x04 ? BlendPixelTrait : UndefinedPixelTrait;
    number_planes=(size_t) ReadBlobByte(image);
    bits_per_pixel=(size_t) ReadBlobByte(image);
    number_colormaps=(size_t) ReadBlobByte(image);
    map_length=(unsigned char) ReadBlobByte(image);
    if (map_length >= 22)
      ThrowReaderException(CorruptImageError,"ImproperImageHeader");
    one=1;
    map_length=one << map_length;
    if ((number_planes == 0) || (number_planes == 2) ||
        ((flags & 0x04) && (number_colormaps > 254)) || (bits_per_pixel != 8) ||
        (image->columns == 0))
      ThrowReaderException(CorruptImageError,"ImproperImageHeader");
    if (flags & 0x02)
      {
        /*
          No background color-- initialize to black.
        */
        for (i=0; i < (ssize_t) number_planes; i++)
          background_color[i]=0;
        (void) ReadBlobByte(image);
      }
    else
      {
        /*
          Initialize background color.
        */
        p=background_color;
        for (i=0; i < (ssize_t) number_planes; i++)
          *p++=(unsigned char) ReadBlobByte(image);
      }
    if ((number_planes & 0x01) == 0)
      (void) ReadBlobByte(image);
    if (EOFBlob(image) != MagickFalse)
      {
        ThrowFileException(exception,CorruptImageError,"UnexpectedEndOfFile",
          image->filename);
        break;
      }
    colormap=(unsigned char *) NULL;
    if (number_colormaps != 0)
      {
        /*
          Read image colormaps.
        */
        colormap=(unsigned char *) AcquireQuantumMemory(number_colormaps,
          3*map_length*sizeof(*colormap));
        if (colormap == (unsigned char *) NULL)
          ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
        p=colormap;
        for (i=0; i < (ssize_t) number_colormaps; i++)
          for (x=0; x < (ssize_t) map_length; x++)
            *p++=(unsigned char) ScaleShortToQuantum(ReadBlobLSBShort(image));
      }
    if ((flags & 0x08) != 0)
      {
        char
          *comment;

        size_t
          length;

        /*
          Read image comment.
        */
        length=ReadBlobLSBShort(image);
        if (length != 0)
          {
            comment=(char *) AcquireQuantumMemory(length,sizeof(*comment));
            if (comment == (char *) NULL)
              ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
            count=ReadBlob(image,length-1,(unsigned char *) comment);
            comment[length-1]='\0';
            (void) SetImageProperty(image,"comment",comment,exception);
            comment=DestroyString(comment);
            if ((length & 0x01) == 0)
              (void) ReadBlobByte(image);
          }
      }
    if (EOFBlob(image) != MagickFalse)
      {
        ThrowFileException(exception,CorruptImageError,"UnexpectedEndOfFile",
          image->filename);
        break;
      }
    if ((image_info->ping != MagickFalse) && (image_info->number_scenes != 0))
      if (image->scene >= (image_info->scene+image_info->number_scenes-1))
        break;
    status=SetImageExtent(image,image->columns,image->rows,exception);
    if (status == MagickFalse)
      return(DestroyImageList(image));
    /*
      Allocate RLE pixels.
    */
    if (image->alpha_trait != UndefinedPixelTrait)
      number_planes++;
    number_pixels=(MagickSizeType) image->columns*image->rows;
    number_planes_filled=(number_planes % 2 == 0) ? number_planes :
      number_planes+1;
    if ((number_pixels*number_planes_filled) != (size_t) (number_pixels*
         number_planes_filled))
      ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
    pixel_info=AcquireVirtualMemory(image->columns,image->rows*
      MagickMax(number_planes_filled,4)*sizeof(*pixels));
    if (pixel_info == (MemoryInfo *) NULL)
      ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
     pixel_info_length=image->columns*image->rows*
       MagickMax(number_planes_filled,4);
     pixels=(unsigned char *) GetVirtualMemoryBlob(pixel_info);
    (void) ResetMagickMemory(pixels,0,pixel_info_length);
     if ((flags & 0x01) && !(flags & 0x02))
       {
         ssize_t
          j;

        /*
          Set background color.
        */
        p=pixels;
        for (i=0; i < (ssize_t) number_pixels; i++)
        {
          if (image->alpha_trait == UndefinedPixelTrait)
            for (j=0; j < (ssize_t) number_planes; j++)
              *p++=background_color[j];
          else
            {
              for (j=0; j < (ssize_t) (number_planes-1); j++)
                *p++=background_color[j];
              *p++=0;  /* initialize matte channel */
            }
        }
      }
    /*
      Read runlength-encoded image.
    */
    plane=0;
    x=0;
    y=0;
    opcode=ReadBlobByte(image);
    do
    {
      switch (opcode & 0x3f)
      {
        case SkipLinesOp:
        {
          operand=ReadBlobByte(image);
          if (opcode & 0x40)
            operand=ReadBlobLSBSignedShort(image);
          x=0;
          y+=operand;
          break;
        }
        case SetColorOp:
        {
          operand=ReadBlobByte(image);
          plane=(unsigned char) operand;
          if (plane == 255)
            plane=(unsigned char) (number_planes-1);
          x=0;
          break;
        }
        case SkipPixelsOp:
        {
          operand=ReadBlobByte(image);
          if (opcode & 0x40)
            operand=ReadBlobLSBSignedShort(image);
          x+=operand;
          break;
        }
        case ByteDataOp:
        {
          operand=ReadBlobByte(image);
          if (opcode & 0x40)
            operand=ReadBlobLSBSignedShort(image);
          offset=((image->rows-y-1)*image->columns*number_planes)+x*
            number_planes+plane;
          operand++;
          if ((offset < 0) ||
              (offset+((size_t) operand*number_planes) > pixel_info_length))
            {
              if (number_colormaps != 0)
                colormap=(unsigned char *) RelinquishMagickMemory(colormap);
              pixel_info=RelinquishVirtualMemory(pixel_info);
              ThrowReaderException(CorruptImageError,"UnableToReadImageData");
            }
          p=pixels+offset;
          for (i=0; i < (ssize_t) operand; i++)
          {
            pixel=(unsigned char) ReadBlobByte(image);
            if ((y < (ssize_t) image->rows) &&
                ((x+i) < (ssize_t) image->columns))
              *p=pixel;
            p+=number_planes;
          }
          if (operand & 0x01)
            (void) ReadBlobByte(image);
          x+=operand;
          break;
        }
        case RunDataOp:
        {
          operand=ReadBlobByte(image);
          if (opcode & 0x40)
            operand=ReadBlobLSBSignedShort(image);
          pixel=(unsigned char) ReadBlobByte(image);
          (void) ReadBlobByte(image);
          offset=((image->rows-y-1)*image->columns*number_planes)+x*
            number_planes+plane;
          operand++;
          if ((offset < 0) ||
              (offset+((size_t) operand*number_planes) > pixel_info_length))
            {
              if (number_colormaps != 0)
                colormap=(unsigned char *) RelinquishMagickMemory(colormap);
              pixel_info=RelinquishVirtualMemory(pixel_info);
              ThrowReaderException(CorruptImageError,"UnableToReadImageData");
            }
          p=pixels+offset;
          for (i=0; i < (ssize_t) operand; i++)
          {
            if ((y < (ssize_t) image->rows) &&
                ((x+i) < (ssize_t) image->columns))
              *p=pixel;
            p+=number_planes;
          }
          x+=operand;
          break;
        }
        default:
          break;
      }
      opcode=ReadBlobByte(image);
    } while (((opcode & 0x3f) != EOFOp) && (opcode != EOF));
    if (number_colormaps != 0)
      {
        MagickStatusType
          mask;

        /*
          Apply colormap affineation to image.
        */
        mask=(MagickStatusType) (map_length-1);
        p=pixels;
        x=(ssize_t) number_planes;
        if (number_colormaps == 1)
          for (i=0; i < (ssize_t) number_pixels; i++)
          {
            ValidateColormapValue(image,*p & mask,&index,exception);
            *p=colormap[(ssize_t) index];
            p++;
          }
        else
          if ((number_planes >= 3) && (number_colormaps >= 3))
            for (i=0; i < (ssize_t) number_pixels; i++)
              for (x=0; x < (ssize_t) number_planes; x++)
              {
                ValidateColormapValue(image,(size_t) (x*map_length+
                    (*p & mask)),&index,exception);
                *p=colormap[(ssize_t) index];
                p++;
              }
        if ((i < (ssize_t) number_pixels) || (x < (ssize_t) number_planes))
          {
            colormap=(unsigned char *) RelinquishMagickMemory(colormap);
            pixel_info=RelinquishVirtualMemory(pixel_info);
            ThrowReaderException(CorruptImageError,"UnableToReadImageData");
          }
      }
    /*
      Initialize image structure.
    */
    if (number_planes >= 3)
      {
        /*
          Convert raster image to DirectClass pixel packets.
        */
        p=pixels;
        for (y=0; y < (ssize_t) image->rows; y++)
        {
          q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
          if (q == (Quantum *) NULL)
            break;
          for (x=0; x < (ssize_t) image->columns; x++)
          {
            SetPixelRed(image,ScaleCharToQuantum(*p++),q);
            SetPixelGreen(image,ScaleCharToQuantum(*p++),q);
            SetPixelBlue(image,ScaleCharToQuantum(*p++),q);
            if (image->alpha_trait != UndefinedPixelTrait)
              SetPixelAlpha(image,ScaleCharToQuantum(*p++),q);
            q+=GetPixelChannels(image);
          }
          if (SyncAuthenticPixels(image,exception) == MagickFalse)
            break;
          if (image->previous == (Image *) NULL)
            {
              status=SetImageProgress(image,LoadImageTag,(MagickOffsetType) y,
                image->rows);
              if (status == MagickFalse)
                break;
            }
        }
      }
    else
      {
        /*
          Create colormap.
        */
        if (number_colormaps == 0)
          map_length=256;
        if (AcquireImageColormap(image,map_length,exception) == MagickFalse)
          ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
        p=colormap;
        if (number_colormaps == 1)
          for (i=0; i < (ssize_t) image->colors; i++)
          {
            /*
              Pseudocolor.
            */
            image->colormap[i].red=(MagickRealType)
              ScaleCharToQuantum((unsigned char) i);
            image->colormap[i].green=(MagickRealType)
              ScaleCharToQuantum((unsigned char) i);
            image->colormap[i].blue=(MagickRealType)
              ScaleCharToQuantum((unsigned char) i);
          }
        else
          if (number_colormaps > 1)
            for (i=0; i < (ssize_t) image->colors; i++)
            {
              image->colormap[i].red=(MagickRealType)
                ScaleCharToQuantum(*p);
              image->colormap[i].green=(MagickRealType)
                ScaleCharToQuantum(*(p+map_length));
              image->colormap[i].blue=(MagickRealType)
                ScaleCharToQuantum(*(p+map_length*2));
              p++;
            }
        p=pixels;
        if (image->alpha_trait == UndefinedPixelTrait)
          {
            /*
              Convert raster image to PseudoClass pixel packets.
            */
            for (y=0; y < (ssize_t) image->rows; y++)
            {
              q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
              if (q == (Quantum *) NULL)
                break;
              for (x=0; x < (ssize_t) image->columns; x++)
              {
                SetPixelIndex(image,*p++,q);
                q+=GetPixelChannels(image);
              }
              if (SyncAuthenticPixels(image,exception) == MagickFalse)
                break;
              if (image->previous == (Image *) NULL)
                {
                  status=SetImageProgress(image,LoadImageTag,(MagickOffsetType)
                    y,image->rows);
                  if (status == MagickFalse)
                    break;
                }
            }
            (void) SyncImage(image,exception);
          }
        else
          {
            /*
              Image has a matte channel-- promote to DirectClass.
            */
            for (y=0; y < (ssize_t) image->rows; y++)
            {
              q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
              if (q == (Quantum *) NULL)
                break;
              for (x=0; x < (ssize_t) image->columns; x++)
              {
                ValidateColormapValue(image,(ssize_t) *p++,&index,exception);
                SetPixelRed(image,ClampToQuantum(image->colormap[(ssize_t)
                  index].red),q);
                ValidateColormapValue(image,(ssize_t) *p++,&index,exception);
                SetPixelGreen(image,ClampToQuantum(image->colormap[(ssize_t)
                  index].green),q);
                ValidateColormapValue(image,(ssize_t) *p++,&index,exception);
                SetPixelBlue(image,ClampToQuantum(image->colormap[(ssize_t)
                  index].blue),q);
                SetPixelAlpha(image,ScaleCharToQuantum(*p++),q);
                q+=GetPixelChannels(image);
              }
              if (x < (ssize_t) image->columns)
                break;
              if (SyncAuthenticPixels(image,exception) == MagickFalse)
                break;
              if (image->previous == (Image *) NULL)
                {
                  status=SetImageProgress(image,LoadImageTag,(MagickOffsetType)
                    y,image->rows);
                  if (status == MagickFalse)
                    break;
                }
            }
            image->colormap=(PixelInfo *) RelinquishMagickMemory(
              image->colormap);
            image->storage_class=DirectClass;
            image->colors=0;
          }
      }
    if (number_colormaps != 0)
      colormap=(unsigned char *) RelinquishMagickMemory(colormap);
    pixel_info=RelinquishVirtualMemory(pixel_info);
    if (EOFBlob(image) != MagickFalse)
      {
        ThrowFileException(exception,CorruptImageError,"UnexpectedEndOfFile",
          image->filename);
        break;
      }
    /*
      Proceed to next image.
    */
    if (image_info->number_scenes != 0)
      if (image->scene >= (image_info->scene+image_info->number_scenes-1))
        break;
    (void) ReadBlobByte(image);
    count=ReadBlob(image,2,(unsigned char *) magick);
    if ((count != 0) && (memcmp(magick,"\122\314",2) == 0))
      {
        /*
          Allocate next image structure.
        */
        AcquireNextImage(image_info,image,exception);
        if (GetNextImageInList(image) == (Image *) NULL)
          {
            image=DestroyImageList(image);
            return((Image *) NULL);
          }
        image=SyncNextImageInList(image);
        status=SetImageProgress(image,LoadImagesTag,TellBlob(image),
          GetBlobSize(image));
        if (status == MagickFalse)
          break;
      }
  } while ((count != 0) && (memcmp(magick,"\122\314",2) == 0));
  (void) CloseBlob(image);
  return(GetFirstImageInList(image));
}