From: Pekka Paalanen <[email protected]> If the idle_repaint() callback has been scheduled when a weston_output gets destroyed, the callback will hit use-after-free. I have encountered this when migrating the wayland backend to the head-based API, using --sprawl, and closing/disconnecting one of the parent compositor outputs.
Store the idle_repaint callback source, and destroy it in weston_output_release(), ensuring we don't get a stale call to start_repaint_loop later. Signed-off-by: Pekka Paalanen <[email protected]> --- libweston/compositor.c | 8 +++++++- libweston/compositor.h | 3 +++ 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/libweston/compositor.c b/libweston/compositor.c index cf40e0d0..ca0870a3 100644 --- a/libweston/compositor.c +++ b/libweston/compositor.c @@ -2583,6 +2583,7 @@ idle_repaint(void *data) assert(output->repaint_status == REPAINT_BEGIN_FROM_IDLE); output->repaint_status = REPAINT_AWAITING_COMPLETION; + output->idle_repaint_source = NULL; output->start_repaint_loop(output); } @@ -2707,7 +2708,9 @@ weston_output_schedule_repaint(struct weston_output *output) return; output->repaint_status = REPAINT_BEGIN_FROM_IDLE; - wl_event_loop_add_idle(loop, idle_repaint, output); + assert(!output->idle_repaint_source); + output->idle_repaint_source = wl_event_loop_add_idle(loop, idle_repaint, + output); TL_POINT("core_repaint_enter_loop", TLP_OUTPUT(output), TLP_END); } @@ -5594,6 +5597,9 @@ weston_output_release(struct weston_output *output) output->destroying = 1; + if (output->idle_repaint_source) + wl_event_source_remove(output->idle_repaint_source); + if (output->enabled) weston_compositor_remove_output(output); diff --git a/libweston/compositor.h b/libweston/compositor.h index 9d435e5a..017878a0 100644 --- a/libweston/compositor.h +++ b/libweston/compositor.h @@ -215,6 +215,9 @@ struct weston_output { * next repaint should be run */ struct timespec next_repaint; + /** For cancelling the idle_repaint callback on output destruction. */ + struct wl_event_source *idle_repaint_source; + struct weston_output_zoom zoom; int dirty; struct wl_signal frame_signal; -- 2.13.6 _______________________________________________ wayland-devel mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/wayland-devel
