In Xwayland's xwl_unrealize_cursor(), the x_cursor is cleared up only when a device value is provided to the UnrealizeCursor() routine, but if the device is NULL as called from FreeCursor(), the corresponding x_cursor for the xwl_seat is left untouched.
This might cause a segfault when trying to access the unrealized cursor's devPrivates in xwl_seat_set_cursor(). A possible occurrence of this is the client changing the cursor, the Xserver calling FreeCursor() which does UnrealizeCursor() and then the Wayland server sending a pointer enter event, which invokes xwl_seat_set_cursor() while the seat's x_cursor has just been unrealized. To avoid this, walk through all the xwl_seats and clear up all x_cursor matching the cursor being unrealized. Signed-off-by: Olivier Fourdan <[email protected]> Reviewed-by: Jonas Ådahl <[email protected]> --- v2: Use xorg_list_for_each_entry() instead of xorg_list_for_each_entry_safe() as suggested by Jonas and add his r-b as per his review. hw/xwayland/xwayland-cursor.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/hw/xwayland/xwayland-cursor.c b/hw/xwayland/xwayland-cursor.c index 7d14a3d..b2ae93f 100644 --- a/hw/xwayland/xwayland-cursor.c +++ b/hw/xwayland/xwayland-cursor.c @@ -76,6 +76,7 @@ static Bool xwl_unrealize_cursor(DeviceIntPtr device, ScreenPtr screen, CursorPtr cursor) { PixmapPtr pixmap; + struct xwl_screen *xwl_screen; struct xwl_seat *xwl_seat; pixmap = dixGetPrivate(&cursor->devPrivates, &xwl_cursor_private_key); @@ -85,9 +86,9 @@ xwl_unrealize_cursor(DeviceIntPtr device, ScreenPtr screen, CursorPtr cursor) dixSetPrivate(&cursor->devPrivates, &xwl_cursor_private_key, NULL); /* When called from FreeCursor(), device is always NULL */ - if (device) { - xwl_seat = device->public.devicePrivate; - if (xwl_seat && cursor == xwl_seat->x_cursor) + xwl_screen = xwl_screen_get(screen); + xorg_list_for_each_entry(xwl_seat, &xwl_screen->seat_list, link) { + if (cursor == xwl_seat->x_cursor) xwl_seat->x_cursor = NULL; } -- 2.9.3 _______________________________________________ [email protected]: X.Org development Archives: http://lists.x.org/archives/xorg-devel Info: https://lists.x.org/mailman/listinfo/xorg-devel
