From 2e572baf659f5a457c876c6b2d02a217afb401c5 Mon Sep 17 00:00:00 2001 From: Vladimir Sementsov-Ogievskiy Date: Wed, 10 Nov 2021 11:38:00 +0100 Subject: [PATCH] ui/vnc-clipboard: fix adding notifier twice vnc_server_cut_text_caps() is not guaranteed to be called only once. If it called twice, we finally call notifier_list_add() twice with same element. Which leads to loopback QLIST. So, on next notifier_list_notify() we'll loop forever and QEMU stuck. So, let's only register new notifier if it's not yet registered. Note, that similar check is used in vdagent_chr_recv_caps() (before call qemu_clipboard_peer_register()), and also before qemu_clipboard_peer_unregister() call in vdagent_disconnect() and in vnc_disconnect_finish(). Signed-off-by: Vladimir Sementsov-Ogievskiy Message-Id: <20211110103800.2266729-1-vsementsov@virtuozzo.com> Signed-off-by: Gerd Hoffmann --- ui/vnc-clipboard.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/ui/vnc-clipboard.c b/ui/vnc-clipboard.c index 9f077965d0..67284b556c 100644 --- a/ui/vnc-clipboard.c +++ b/ui/vnc-clipboard.c @@ -316,8 +316,10 @@ void vnc_server_cut_text_caps(VncState *vs) caps[1] = 0; vnc_clipboard_send(vs, 2, caps); - vs->cbpeer.name = "vnc"; - vs->cbpeer.update.notify = vnc_clipboard_notify; - vs->cbpeer.request = vnc_clipboard_request; - qemu_clipboard_peer_register(&vs->cbpeer); + if (!vs->cbpeer.update.notify) { + vs->cbpeer.name = "vnc"; + vs->cbpeer.update.notify = vnc_clipboard_notify; + vs->cbpeer.request = vnc_clipboard_request; + qemu_clipboard_peer_register(&vs->cbpeer); + } }