[pve-devel] [PATCH qemu-server 1/1] fix #4321: properly check cloud-init drive permissions

[Thomas Lamprecht]

Am 03/11/2022 um 14:04 schrieb Leo Nunner:
> The process for editing cloud-init drives checked for inconsistent
> permissions: for adding, the VM.Config.Disk permission was needed, while
> the VM.Config.CDROM permission was needed to remove a drive. The regex
> in drive_is_cloudinit needed to be adapted since the drive names have
> different formats before/after they are actually generated. Furthermore,
> the VM.Config.Cloudinit permission should be required to edit
> cloud-init drives.
> 
> Signed-off-by: Leo Nunner <l.nunner at proxmox.com>
> ---
>  PVE/API2/Qemu.pm        | 6 ++++--
>  PVE/QemuServer/Drive.pm | 2 +-
>  2 files changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/PVE/API2/Qemu.pm b/PVE/API2/Qemu.pm
> index 3ec31c2..cacd233 100644
> --- a/PVE/API2/Qemu.pm
> +++ b/PVE/API2/Qemu.pm
> @@ -1512,11 +1512,13 @@ my $update_vm_api  = sub {
>  	    my $check_drive_perms = sub {
>  		my ($opt, $val) = @_;
>  		my $drive = PVE::QemuServer::parse_drive($opt, $val, 1);
> -		# FIXME: cloudinit: CDROM or Disk?
> -		if (PVE::QemuServer::drive_is_cdrom($drive)) { # CDROM
> +		if(PVE::QemuServer::drive_is_cloudinit($drive)) {

missing white after `if`

> +		    $rpcenv->check_vm_perm($authuser, $vmid, undef, ['VM.Config.Cloudinit', 'VM.Config.Disk']);

while I don't think that the perm change is problematic w.r.t. backward compat
in practice, it seems a bit odd to argue for disk only, maybe we need to also
check for CDROM, as cloudinit *adds* a cdrom drive, so it may required that too.

But, to decide that I wanted to check our privilege docs, only to notice that we
do not mention the cloudinit one there at all, not great...

https://pve.proxmox.com/pve-docs/chapter-pveum.html#_privileges

Please check the dev history to see if Cloudinit is deemed enough to add the CDROM
or if we should add that priv to the check too, then re-send this with updated
commit message, the whitespace fixes and a docs patch.