backend: fix use-after-free when destroying backends

The backend destroy signal is emitted before the output_remove
signal is. When the destroy signal is emitted listeners remove
their output_remove listener, so the output_remove signal is never
received and listeners have an invalid output pointer.

The correct way to solve this would be to remove the output_remove
signal completely and use the wlr_output.events.destroy signal
instead. This isn't yet possible because wl_signal_emit is unsafe
and listeners cannot be removed in listeners.
This commit is contained in:
emersion 2018-01-30 19:45:57 +01:00
parent 704130cc11
commit babdd6ccf7
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GPG key ID: 0FDE7BE0E88F5E48
10 changed files with 27 additions and 13 deletions

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@ -64,9 +64,9 @@ static bool wlr_wl_backend_start(struct wlr_backend *_backend) {
return true;
}
static void wlr_wl_backend_destroy(struct wlr_backend *_backend) {
struct wlr_wl_backend *backend = (struct wlr_wl_backend *)_backend;
if (!_backend) {
static void wlr_wl_backend_destroy(struct wlr_backend *wlr_backend) {
struct wlr_wl_backend *backend = (struct wlr_wl_backend *)wlr_backend;
if (backend == NULL) {
return;
}
@ -80,6 +80,8 @@ static void wlr_wl_backend_destroy(struct wlr_backend *_backend) {
wlr_input_device_destroy(input_device);
}
wl_signal_emit(&wlr_backend->events.destroy, wlr_backend);
wl_list_remove(&backend->local_display_destroy.link);
free(backend->seat_name);