sungmg/mutter-performance-source
1
0
Fork 0
Code Activity

wayland: Seal SHM buffers before access

Browse source 
If wayland client lies about size of given buffer, compositor could touch bad
memory and get SIGBUS. Wayland provides simple API to fix it - so fix it!

[1] http://cgit.freedesktop.org/wayland/wayland/tree/src/wayland-server.h#n416
[2] http://lists.freedesktop.org/archives/wayland-devel/2013-November/012159.html

Signed-off-by: Marek Chalupa <mchqwerty@gmail.com>

https://bugzilla.gnome.org/show_bug.cgi?id=727893
This commit is contained in:
Marek Chalupa 2015-01-09 16:09:23 +01:00 committed by Jasper St. Pierre
parent 87eb5f8632
commit b6d070b06f
2 changed files with 18 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
src/backends/meta-cursor.c
View file

@ -317,6 +317,8 @@ meta_cursor_image_load_from_buffer (MetaCursorImage *image,
{
int rowstride = wl_shm_buffer_get_stride (shm_buffer);
wl_shm_buffer_begin_access (shm_buffer);
switch (wl_shm_buffer_get_format (shm_buffer))
{
#if G_BYTE_ORDER == G_BIG_ENDIAN
@ -344,6 +346,8 @@ meta_cursor_image_load_from_buffer (MetaCursorImage *image,
(uint8_t *) wl_shm_buffer_get_data (shm_buffer),
width, height, rowstride,
gbm_format);
wl_shm_buffer_end_access (shm_buffer);
}
else
{

14
src/wayland/meta-wayland-buffer.c
View file

@ -91,13 +91,23 @@ meta_wayland_buffer_ensure_texture (MetaWaylandBuffer *buffer)
CoglContext *ctx = clutter_backend_get_cogl_context (clutter_get_default_backend ());
CoglError *catch_error = NULL;
CoglTexture *texture;
struct wl_shm_buffer *shm_buffer;
if (buffer->texture)
goto out;
shm_buffer = wl_shm_buffer_get (buffer->resource);
if (shm_buffer)
wl_shm_buffer_begin_access (shm_buffer);
texture = COGL_TEXTURE (cogl_wayland_texture_2d_new_from_buffer (ctx,
buffer->resource,
&catch_error));
if (shm_buffer)
wl_shm_buffer_end_access (shm_buffer);
if (!texture)
{
cogl_error_free (catch_error);
@ -124,6 +134,8 @@ meta_wayland_buffer_process_damage (MetaWaylandBuffer *buffer,
n_rectangles = cairo_region_num_rectangles (region);
wl_shm_buffer_begin_access (shm_buffer);
for (i = 0; i < n_rectangles; i++)
{
cairo_rectangle_int_t rect;
@ -133,5 +145,7 @@ meta_wayland_buffer_process_damage (MetaWaylandBuffer *buffer,
shm_buffer,
rect.x, rect.y, 0, NULL);
}
wl_shm_buffer_end_access (shm_buffer);
}
}