vnc: fix possible uninitialized removals

Some VncState values are not initialized before the Websocket handshake.
If it fails QEMU segfaults during the cleanup. To prevent this behavior
intialization checks are added.

Signed-off-by: Tim Hardeck <thardeck@suse.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 8 insertions, 3 deletions

diff --git a/ui/vnc.c b/ui/vnc.c
index ee08894f7f..ff4e2ae586 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -1053,20 +1053,24 @@ void vnc_disconnect_finish(VncState *vs)
     audio_del(vs);
     vnc_release_modifiers(vs);
 
-    QTAILQ_REMOVE(&vs->vd->clients, vs, next);
+    if (vs->initialized) {
+        QTAILQ_REMOVE(&vs->vd->clients, vs, next);
+        qemu_remove_mouse_mode_change_notifier(&vs->mouse_mode_notifier);
+    }
 
     if (QTAILQ_EMPTY(&vs->vd->clients)) {
         dcl->idle = 1;
     }
 
-    qemu_remove_mouse_mode_change_notifier(&vs->mouse_mode_notifier);
     vnc_remove_timer(vs->vd);
     if (vs->vd->lock_key_sync)
         qemu_remove_led_event_handler(vs->led);
     vnc_unlock_output(vs);
 
     qemu_mutex_destroy(&vs->output_mutex);
-    qemu_bh_delete(vs->bh);
+    if (vs->bh != NULL) {
+        qemu_bh_delete(vs->bh);
+    }
     buffer_free(&vs->jobs_buffer);
 
     for (i = 0; i < VNC_STAT_ROWS; ++i) {
@@ -2749,6 +2753,7 @@ static void vnc_connect(VncDisplay *vd, int csock, int skipauth, bool websocket)
 
 void vnc_init_state(VncState *vs)
 {
+    vs->initialized = true;
     VncDisplay *vd = vs->vd;
 
     vs->ds = vd->ds;