diff options
| author | Ilia Bozhinov <ammen99@gmail.com> | 2020-07-19 14:57:10 +0200 |
|---|---|---|
| committer | Simon Ser <contact@emersion.fr> | 2020-07-30 13:40:36 +0200 |
| commit | 74f7be728715e164d5b7f174491797ce31206c8d (patch) | |
| tree | 9a2bd9955b72ecdebf930f5b53e5d984ded79fd4 /xwayland | |
| parent | 1dbcfdaf81778fcd4635c6ecd62b89477f69f0d8 (diff) | |
xwayland: do not allow apps to change focus after wlroots request
Diffstat (limited to 'xwayland')
| -rw-r--r-- | xwayland/xwm.c | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/xwayland/xwm.c b/xwayland/xwm.c index 88f4c3c5..87b9edc1 100644 --- a/xwayland/xwm.c +++ b/xwayland/xwm.c @@ -275,8 +275,9 @@ static void xwm_set_focus_window(struct wlr_xwm *xwm, } else { xwm_send_wm_message(xsurface, &message_data, XCB_EVENT_MASK_SUBSTRUCTURE_REDIRECT); - xcb_set_input_focus(xwm->xcb_conn, XCB_INPUT_FOCUS_POINTER_ROOT, - xsurface->window_id, XCB_CURRENT_TIME); + xcb_void_cookie_t cookie = xcb_set_input_focus(xwm->xcb_conn, + XCB_INPUT_FOCUS_POINTER_ROOT, xsurface->window_id, XCB_CURRENT_TIME); + xwm->last_focus_seq = cookie.sequence; } uint32_t values[1]; @@ -1293,6 +1294,16 @@ static void xwm_handle_client_message(struct wlr_xwm *xwm, } } +static bool validate_focus_serial(uint16_t last_focus_seq, uint16_t event_seq) { + uint16_t rev_dist = event_seq - last_focus_seq; + if (rev_dist >= UINT16_MAX / 2) { + // Probably overflow or too old + return false; + } + + return true; +} + static void xwm_handle_focus_in(struct wlr_xwm *xwm, xcb_focus_in_event_t *ev) { // Do not interfere with grabs @@ -1311,10 +1322,13 @@ static void xwm_handle_focus_in(struct wlr_xwm *xwm, // Note: Some applications rely on being able to change focus, for ex. Steam: // https://github.com/swaywm/sway/issues/1865 // Because of that, we allow changing focus between surfaces belonging to the - // same application. + // same application. We must be careful to ignore requests that are too old + // though, because otherwise it may lead to race conditions: + // https://github.com/swaywm/wlroots/issues/2324 struct wlr_xwayland_surface *requested_focus = lookup_surface(xwm, ev->event); if (xwm->focus_surface && requested_focus && - requested_focus->pid == xwm->focus_surface->pid) { + requested_focus->pid == xwm->focus_surface->pid && + validate_focus_serial(xwm->last_focus_seq, ev->sequence)) { xwm_set_focus_window(xwm, requested_focus); } else { xwm_set_focus_window(xwm, xwm->focus_surface); |