xserver/hw
Olivier Fourdan cdd0352ba0 xwayland: Fix a segfault with pointer locking
Xwayland would crash in some circumstances while trying to issue a
pointer locking when the cursor is hidden when there is no seat focus
window set.

The crash signature looks like:

 #0  zwp_pointer_constraints_v1_lock_pointer ()
 #1  xwl_pointer_warp_emulator_lock () at xwayland-input.c:2584
 #2  xwl_seat_maybe_lock_on_hidden_cursor () at xwayland-input.c:2756
 #3  xwl_seat_maybe_lock_on_hidden_cursor () at xwayland-input.c:2765
 #4  xwl_seat_cursor_visibility_changed () at xwayland-input.c:2768
 #5  xwl_set_cursor () at xwayland-cursor.c:245
 #6  miPointerUpdateSprite () at mipointer.c:468
 #7  miPointerDisplayCursor () at mipointer.c:206
 #8  CursorDisplayCursor () at cursor.c:150
 #9  AnimCurDisplayCursor () at animcur.c:220
 #10 ChangeToCursor () at events.c:936
 #11 ActivatePointerGrab () at events.c:1542
 #12 GrabDevice () at events.c:5120
 #13 ProcGrabPointer () at events.c:4908
 #14 Dispatch () at dispatch.c:478
 #15 dix_main () at main.c:276

xwl_pointer_warp_emulator_lock() tries to use the surface from the
xwl_seat->focus_window leading to a NULL pointer dereference when that
value is NULL.

Check that xwl_seat->focus_window is not NULL earlier in the stack in
xwl_seat_maybe_lock_on_hidden_cursor() and return early if not the case
to avoid the crash.

Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=102474
Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Acked-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
2017-09-05 11:35:40 +10:00
..
dmx dmx: Remove some not-very-interesting debug prints 2017-06-20 16:39:23 -04:00
kdrive xephyr: Fix regeneration 2017-05-11 14:13:12 -04:00
vfb Add a Meson build system alongside autotools. 2017-04-26 15:25:27 -07:00
xfree86 Make PixmapDirtyUpdateRec::src a DrawablePtr 2017-08-15 17:01:39 +09:00
xnest Add a Meson build system alongside autotools. 2017-04-26 15:25:27 -07:00
xquartz XQuartz: Hack around an issue that can occur on macOS due to background apps incorrectly stealing focus 2017-07-20 01:17:40 -07:00
xwayland xwayland: Fix a segfault with pointer locking 2017-09-05 11:35:40 +10:00
xwin xwin: automake: remove unused {SRCS, DEFS}_{NATIVEGDI, PRIMARYFB} 2017-08-22 10:59:41 -04:00
Makefile.am Xwayland DDX 2014-04-03 15:19:22 -07:00
meson.build Add meson.build for XWin server (v2) 2017-06-02 09:32:35 -07:00