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# HG changeset patch
# User Bob Friesenhahn <bfriesen@GraphicsMagick.org>
# Date 1555263241 18000
# Node ID 5402c5cbd8bdce7d59a6f2253bf7841220122528
# Parent ce367bc7f85e0b1fd312c8cbd024cb502b12985b
ReadXWDImage(): Add more validation logic to avoid crashes due to FPE and invalid reads.
diff -r ce367bc7f85e -r 5402c5cbd8bd coders/xwd.c
--- a/coders/xwd.c Sat Apr 13 13:40:50 2019 -0500
+++ b/coders/xwd.c Sun Apr 14 12:34:01 2019 -0500
@@ -321,6 +321,7 @@
if (header.header_size < sz_XWDheader)
ThrowXWDReaderException(CorruptImageError,ImproperImageHeader,image);
+ /* Display classes used in opening the connection */
switch (header.visual_class)
{
case StaticGray:
@@ -335,11 +336,43 @@
ThrowXWDReaderException(CorruptImageError,ImproperImageHeader,image);
}
}
+
+ /* XYBitmap, XYPixmap, ZPixmap */
switch (header.pixmap_format)
{
- case XYBitmap:
- case XYPixmap:
- case ZPixmap:
+ case XYBitmap: /* 1 bit bitmap format */
+ if (header.pixmap_depth != 1)
+ ThrowXWDReaderException(CorruptImageError,ImproperImageHeader,image);
+ break;
+ case XYPixmap: /* Single plane bitmap. */
+ case ZPixmap: /* Bitmap with 2 or more planes */
+ if ((header.pixmap_depth < 1) || (header.pixmap_depth > 32))
+ ThrowXWDReaderException(CorruptImageError,ImproperImageHeader,image);
+ break;
+ default:
+ {
+ ThrowXWDReaderException(CorruptImageError,ImproperImageHeader,image);
+ }
+ }
+
+ /* Data byte order, LSBFirst, MSBFirst */
+ switch (header.byte_order)
+ {
+ case LSBFirst:
+ case MSBFirst:
+ break;
+ default:
+ {
+ ThrowXWDReaderException(CorruptImageError,ImproperImageHeader,image);
+ }
+ }
+
+ /* Quant. of scanline 8, 16, 32 */
+ switch (header.bitmap_unit)
+ {
+ case 8:
+ case 16:
+ case 32:
break;
default:
{
@@ -347,8 +380,59 @@
}
}
- if ((header.bits_per_pixel == 0) || (header.bits_per_pixel > 32))
- ThrowXWDReaderException(CorruptImageError,ImproperImageHeader,image);
+ /* LSBFirst, MSBFirst */
+ switch (header.bitmap_bit_order)
+ {
+ case LSBFirst:
+ case MSBFirst:
+ break;
+ default:
+ {
+ ThrowXWDReaderException(CorruptImageError,ImproperImageHeader,image);
+ }
+ }
+
+ /* 8, 16, 32 either XY or ZPixmap */
+ if ((header.pixmap_format == XYPixmap) || (header.pixmap_format == ZPixmap))
+ switch (header.bitmap_pad)
+ {
+ case 8:
+ case 16:
+ case 32:
+ break;
+ default:
+ {
+ ThrowXWDReaderException(CorruptImageError,ImproperImageHeader,image);
+ }
+ }
+
+ /* Bits per pixel (ZPixmap) */
+ switch (header.visual_class)
+ {
+ case StaticGray:
+ case GrayScale:
+ /* Gray-scale image */
+ if (header.bits_per_pixel != 1)
+ ThrowXWDReaderException(CorruptImageError,ImproperImageHeader,image);
+ break;
+ case StaticColor:
+ case PseudoColor:
+ /* Color-mapped image */
+ if ((header.bits_per_pixel < 1) || (header.bits_per_pixel > 15) ||
+ (header.colormap_entries == 0))
+ ThrowXWDReaderException(CorruptImageError,ImproperImageHeader,image);
+ break;
+ case TrueColor:
+ case DirectColor:
+ /* True-color image */
+ if ((header.bits_per_pixel != 16) && (header.bits_per_pixel != 24) &&
+ (header.bits_per_pixel != 32))
+ ThrowXWDReaderException(CorruptImageError,ImproperImageHeader,image);
+ break;
+ }
+
+
+ /* 8, 16, 32 either XY or ZPixmap */
if ((header.bitmap_pad % 8 != 0) || (header.bitmap_pad > 32))
ThrowXWDReaderException(CorruptImageError,ImproperImageHeader,image);
@@ -417,6 +501,7 @@
*/
if (ximage->width < 0 ||
ximage->height < 0 ||
+ ximage->xoffset < 0 ||
ximage->format < 0 ||
ximage->byte_order < 0 ||
ximage->bitmap_unit < 0 ||
@@ -439,10 +524,15 @@
if (CheckImagePixelLimits(image, exception) != MagickPass)
ThrowXWDReaderException(ResourceLimitError,ImagePixelLimitExceeded,image);
image->depth=8;
- if ((header.ncolors == 0U) ||
- ((ximage->red_mask != 0) ||
- (ximage->green_mask != 0) ||
- (ximage->blue_mask != 0)))
+
+ /*
+ FIXME: This block of logic should be re-worked.
+ */
+ if ((header.visual_class != StaticGray) &&
+ ((header.ncolors == 0U) ||
+ ((ximage->red_mask != 0) ||
+ (ximage->green_mask != 0) ||
+ (ximage->blue_mask != 0))))
{
image->storage_class=DirectClass;
if (!image_info->ping)
@@ -454,7 +544,7 @@
else
{
image->storage_class=PseudoClass;
- image->colors=header.ncolors;
+ image->colors=header.visual_class == StaticGray ? 2 : header.ncolors;
}
if (!image_info->ping)
{
@@ -664,11 +754,14 @@
if (!AllocateImageColormap(image,image->colors))
ThrowXWDReaderException(ResourceLimitError,MemoryAllocationFailed,
image);
- for (i=0; i < (long) image->colors; i++)
+ if (colors != (XColor *) NULL)
{
- image->colormap[i].red=ScaleShortToQuantum(colors[i].red);
- image->colormap[i].green=ScaleShortToQuantum(colors[i].green);
- image->colormap[i].blue=ScaleShortToQuantum(colors[i].blue);
+ for (i=0; i < (long) image->colors; i++)
+ {
+ image->colormap[i].red=ScaleShortToQuantum(colors[i].red);
+ image->colormap[i].green=ScaleShortToQuantum(colors[i].green);
+ image->colormap[i].blue=ScaleShortToQuantum(colors[i].blue);
+ }
}
for (y=0; y < (long) image->rows; y++)
{
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