To avoid any possibility of uninitialized memory.
The exceptions are:
- where the allocation is immediately overwritten by a memcpy or struct copy.
- arrays of structs to avoid any performance impact (except when the
array is returned by the public API).
_cairo_malloc(0) always returns NULL, but has not been used
consistently. This patch replaces many calls to malloc() with
_cairo_malloc().
Fixes: fdo# 101547
CVE: CVE-2017-9814 Heap buffer overflow at cairo-truetype-subset.c:1299
Reviewed-by: Bryce Harrington <bryce@osg.samsung.com>
Otherwise we leave dangling pointers in the visual list, leading to
memory corruption when using low bitdepth servers.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
45665c0d48 breaks the build of
cairo-xlib-xcb because it does not disable the compilation of
cairo-xlib implementation files when cairo-xlib-xcb is enable. This
results in collisions when linking.
Reported-by: James Cloos <cloos@jhcloos.com>
I updated the Free Software Foundation address using the following script.
for i in $(git grep Temple | cut -d: -f1 )
do
sed -e 's/59 Temple Place[, -]* Suite 330, Boston, MA *02111-1307[, ]* USA/51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA/' -i "$i"
done
Fixes http://bugs.freedesktop.org/show_bug.cgi?id=21356
Remove the intermediate rgb333 for PseudoColor and work on the
cube directly. Also upgrade to a 6x6x6 cube instead of 5x5x5.
Do dithering on both PseudoColor and TrueColor, using a 4x4 pattern.
This only affects X servers with no XRender.
That is, instead of uniformly spreading the colors at 0/4, 1/4, 2/4, 3/4, 4/4
intensities, we do 0/7, 1.5/7, 3.5/7, 5.5/7, 7/7 now. Those better
approximate the 0/7..7/7 of the rgb333 space that we first convert to.
This support involves allocating a 16-bit grayscale ramp as well
as a 5x5x5 RGB color cube. Afterwards, the 256 colors are queried
and an array is generated mapping from r3g3b3 colors to the closest
available color. Both the queried colors and the reverse mapping
are stored in a new visual-specific cairo_xlib_visual_info_t
structure which hangs off of the cairo_xlib_screen_info_t.
Both the color-cube allocation and the distance metric could be
improved by someone sufficiently motivated, (for example, allocating
and matching in a perceptually linear color space rather than just
in RGB space). Also, making this work well in the face of a changing
color map, or in the case of GrayScale, StaticGray, or DirectColor
visuals are left entirely as exercises for the reader. StaticColor
support should be fine as is, but is entirely untested.
