Re: [pve-devel] [PATCH v2 qemu] add fix for vnc clipboard

[Friedrich Weber <f.weber@proxmox.com>]

Installed a patched pve-qemu-kvm package provided by Fiona and can
confirm that the host->guest clipboard direction works now.

More specifically: Entering something in the noVNC clipboard textbox,
trying to paste in a text editor running inside a Debian Bullseye+XFCE
VM with spice-vdagent 0.20.0-2. Without the patch, the editor froze for
a few seconds and nothing was pasted. With the patch, pasting works again.

Would be great if we could get this in, as the VNC clipboard is
half-broken without it.

Tested-by: Friedrich Weber <f.weber@proxmox.com>

On 22/11/2023 13:41, Fiona Ebner wrote:
> This fixes the host->guest direction with noNVC as a client (and
> likely others).
> 
> Reported-by: Friedrich Weber <f.weber@proxmox.com>
> Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
> ---
>  ...-ui-vnc-clipboard-fix-inflate_buffer.patch | 34 +++++++++++++++++++
>  debian/patches/series                         |  1 +
>  2 files changed, 35 insertions(+)
>  create mode 100644 debian/patches/extra/0010-ui-vnc-clipboard-fix-inflate_buffer.patch
> 
> diff --git a/debian/patches/extra/0010-ui-vnc-clipboard-fix-inflate_buffer.patch b/debian/patches/extra/0010-ui-vnc-clipboard-fix-inflate_buffer.patch
> new file mode 100644
> index 0000000..4711fa0
> --- /dev/null
> +++ b/debian/patches/extra/0010-ui-vnc-clipboard-fix-inflate_buffer.patch
> @@ -0,0 +1,34 @@
> +From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
> +From: Fiona Ebner <f.ebner@proxmox.com>
> +Date: Wed, 22 Nov 2023 13:17:25 +0100
> +Subject: [PATCH] ui/vnc-clipboard: fix inflate_buffer
> +
> +Commit d921fea338 ("ui/vnc-clipboard: fix infinite loop in
> +inflate_buffer (CVE-2023-3255)") removed this hunk, but it is still
> +required, because it can happen that stream.avail_in becomes zero
> +before coming across a return value of Z_STREAM_END.
> +
> +This fixes the host->guest direction with noNVC.
> +
> +Reported-by: Friedrich Weber <f.weber@proxmox.com>
> +Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
> +---
> + ui/vnc-clipboard.c | 5 +++++
> + 1 file changed, 5 insertions(+)
> +
> +diff --git a/ui/vnc-clipboard.c b/ui/vnc-clipboard.c
> +index c759be3438..124b6fbd9c 100644
> +--- a/ui/vnc-clipboard.c
> ++++ b/ui/vnc-clipboard.c
> +@@ -69,6 +69,11 @@ static uint8_t *inflate_buffer(uint8_t *in, uint32_t in_len, uint32_t *size)
> +         }
> +     }
> + 
> ++    *size = stream.total_out;
> ++    inflateEnd(&stream);
> ++
> ++    return out;
> ++
> + err_end:
> +     inflateEnd(&stream);
> + err:
> diff --git a/debian/patches/series b/debian/patches/series
> index 992299c..9938b8e 100644
> --- a/debian/patches/series
> +++ b/debian/patches/series
> @@ -7,6 +7,7 @@ extra/0006-Revert-Revert-graph-lock-Disable-locking-for-now.patch
>  extra/0007-migration-states-workaround-snapshot-performance-reg.patch
>  extra/0008-Revert-x86-acpi-workaround-Windows-not-handling-name.patch
>  extra/0009-hw-ide-ahci-fix-legacy-software-reset.patch
> +extra/0010-ui-vnc-clipboard-fix-inflate_buffer.patch
>  bitmap-mirror/0001-drive-mirror-add-support-for-sync-bitmap-mode-never.patch
>  bitmap-mirror/0002-drive-mirror-add-support-for-conditional-and-always-.patch
>  bitmap-mirror/0003-mirror-add-check-for-bitmap-mode-without-bitmap.patch