From 965275cd87f8008f129509c6d6fd0096e8ac2d96 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= Date: Mon, 14 Feb 2022 15:59:17 +0400 Subject: [PATCH 3/6] ui/clipboard: fix use-after-free regression MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Gerd Hoffmann RH-MergeRequest: 75: fix vnc cut+paste crash RH-Commit: [3/4] d8f68e0eb60d9aaa9a703d969f215816bf35f6f0 (kraxel/centos-qemu-kvm) RH-Bugzilla: 2042820 RH-Acked-by: Marc-André Lureau RH-Acked-by: Daniel P. Berrangé RH-Acked-by: Miroslav Rezanina The same info may be used to update the clipboard, and may be freed before being ref'ed again. Fixes: 70a54b01693ed ("ui: avoid compiler warnings from unused clipboard info variable") Signed-off-by: Marc-André Lureau Reviewed-by: Daniel P. Berrangé Message-Id: <20220214115917.1679568-1-marcandre.lureau@redhat.com> Signed-off-by: Gerd Hoffmann --- ui/clipboard.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/ui/clipboard.c b/ui/clipboard.c index 7672058e84..d7dae13760 100644 --- a/ui/clipboard.c +++ b/ui/clipboard.c @@ -48,8 +48,10 @@ void qemu_clipboard_update(QemuClipboardInfo *info) notifier_list_notify(&clipboard_notifiers, info); - qemu_clipboard_info_unref(cbinfo[info->selection]); - cbinfo[info->selection] = qemu_clipboard_info_ref(info); + if (cbinfo[info->selection] != info) { + qemu_clipboard_info_unref(cbinfo[info->selection]); + cbinfo[info->selection] = qemu_clipboard_info_ref(info); + } } QemuClipboardInfo *qemu_clipboard_info(QemuClipboardSelection selection) -- 2.27.0