[Qemu-devel] [PATCH 3/3] vnc: fix possible uninitialized removals

[Tim Hardeck <thardeck@suse.de>]

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>
---
 ui/vnc.c |   11 ++++++++---
 ui/vnc.h |    1 +
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/ui/vnc.c b/ui/vnc.c
index ee08894..ff4e2ae 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;
diff --git a/ui/vnc.h b/ui/vnc.h
index f93c89a..45d7686 100644
--- a/ui/vnc.h
+++ b/ui/vnc.h
@@ -306,6 +306,7 @@ struct VncState
     QEMUPutLEDEntry *led;
 
     bool abort;
+    bool initialized;
     QemuMutex output_mutex;
     QEMUBH *bh;
     Buffer jobs_buffer;
-- 
1.7.10.4