Re: [PATCH v3 2/2] ui/clipboard: add asserts for update and request

[Marc-André Lureau]

On Wed, Jan 24, 2024 at 2:59 PM Fiona Ebner <f.ebner@proxmox.com> wrote:
>
> Should an issue like CVE-2023-6683 ever appear again in the future,
> it will be more obvious which assumption was violated.
>
> Suggested-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>

thanks

> ---
>
> Changes in v3:
>     * Turn check for update into an assertion.
>     * Split out into a separate patch.
>
>  ui/clipboard.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
>
> diff --git a/ui/clipboard.c b/ui/clipboard.c
> index b3f6fa3c9e..4264884a6c 100644
> --- a/ui/clipboard.c
> +++ b/ui/clipboard.c
> @@ -65,12 +65,24 @@ bool qemu_clipboard_check_serial(QemuClipboardInfo *info, 
> bool client)
>
>  void qemu_clipboard_update(QemuClipboardInfo *info)
>  {
> +    uint32_t type;
>      QemuClipboardNotify notify = {
>          .type = QEMU_CLIPBOARD_UPDATE_INFO,
>          .info = info,
>      };
>      assert(info->selection < QEMU_CLIPBOARD_SELECTION__COUNT);
>
> +    for (type = 0; type < QEMU_CLIPBOARD_TYPE__COUNT; type++) {
> +        /*
> +         * If data is missing, the clipboard owner's 'request' callback 
> needs to
> +         * be set. Otherwise, there is no way to get the clipboard data and
> +         * qemu_clipboard_request() cannot be called.
> +         */
> +        if (info->types[type].available && !info->types[type].data) {
> +            assert(info->owner && info->owner->request);
> +        }
> +    }
> +
>      notifier_list_notify(&clipboard_notifiers, &notify);
>
>      if (cbinfo[info->selection] != info) {
> @@ -132,6 +144,8 @@ void qemu_clipboard_request(QemuClipboardInfo *info,
>          !info->owner)
>          return;
>
> +    assert(info->owner->request);
> +
>      info->types[type].requested = true;
>      info->owner->request(info, type);
>  }
> --
> 2.39.2
>
>
>


-- 
Marc-André Lureau