[pve-devel] [PATCH qemu-server 2/3] suspend to disk: check more permissions

[Fabian Grünbichler]

On December 5, 2019 3:38 pm, Dominik Csapak wrote:
> only VM.PowerMgmt is not enough, since we allocate space on a storage,
> so we need VM.Config.Disk on the vm and Datastore.AllocateSpace on the storage
> 
> Signed-off-by: Dominik Csapak <d.csapak at proxmox.com>
> ---
> i am not sure if we need the last hunk (the check inside vm_suspend) at all,
> since we now always give a statestorage to vm_suspend and this api call
> is the only user of that parameter...
> 
> but i would like to hear others people opinions, since i believe
> i am overlooking something
> 
>  PVE/API2/Qemu.pm  | 20 ++++++++++++++++++++
>  PVE/QemuServer.pm | 11 +++++++++++
>  2 files changed, 31 insertions(+)
> 
> diff --git a/PVE/API2/Qemu.pm b/PVE/API2/Qemu.pm
> index 51fe142..9b25106 100644
> --- a/PVE/API2/Qemu.pm
> +++ b/PVE/API2/Qemu.pm
> @@ -2387,6 +2387,9 @@ __PACKAGE__->register_method({
>      proxyto => 'node',
>      description => "Suspend virtual machine.",
>      permissions => {
> +	description => "You need 'VM.PowerMgmt' on /vms/{vmid}, and if you have set 'todisk',".
> +	    " you need also 'VM.Config.Disk' on /vms/{vmid} and 'Datastore.AllocateSpace'".
> +	    " on the storage for the vmstate.",
>  	check => ['perm', '/vms/{vmid}', [ 'VM.PowerMgmt' ]],
>      },
>      parameters => {
> @@ -2435,6 +2438,23 @@ __PACKAGE__->register_method({
>  	die "Cannot suspend HA managed VM to disk\n"
>  	    if $todisk && PVE::HA::Config::vm_is_ha_managed($vmid);
>  
> +	# early check for storage permission, will again be checked
> +	# in vm_suspend to avoid races with config writes
> +	if ($todisk) {
> +	    $rpcenv->check_vm_perm($authuser, $vmid, undef, ['VM.Config.Disk']);
> +
> +	    if (!$statestorage) {

UX nit: we need to give the user the option to set a vmstatestorage on 
the GUI now - otherwise this might reliably pick a storage that the user 
cannot access, while there are other storages where they might be 
allowed to allocate a vmstate volume but they don't get that choice.

-> make vmstatestorage option editable on GUI
-> display a storage selector in hibernate dialogue, pre-select 
vmstatestorage from config if set, allow any storages that the user can 
access

> +		# get statestorage from config if none is given
> +		PVE::QemuConfig->lock_config($vmid, sub {
> +		    my $conf = PVE::QemuConfig->load_config($vmid);
> +		    my $storecfg = PVE::Storage::config();
> +		    $statestorage = PVE::QemuServer::find_vmstate_storage($conf, $storecfg);
> +		});
> +	    }
> +
> +	    $rpcenv->check($authuser, "/storage/$statestorage", ['Datastore.AllocateSpace']);
> +	}
> +
>  	my $realcmd = sub {
>  	    my $upid = shift;
>  
> diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
> index 33b1d50..23d71f4 100644
> --- a/PVE/QemuServer.pm
> +++ b/PVE/QemuServer.pm
> @@ -5761,6 +5761,17 @@ sub vm_suspend {
>  	    $conf->{lock} = 'suspending';
>  	    my $date = strftime("%Y-%m-%d", localtime(time()));
>  	    $storecfg = PVE::Storage::config();
> +	    if (!$statestorage) {
> +		$statestorage = find_vmstate_storage($conf, $storecfg);
> +	    }
> +
> +	    # check permissions for the storage
> +	    my $rpcenv = PVE::RPCEnvironment::get();
> +	    if ($rpcenv->{type} ne 'cli') {
> +		my $authuser = $rpcenv->get_user();
> +		$rpcenv->check($authuser, "/storage/$statestorage", ['Datastore.AllocateSpace']);
> +	    }
> +
>  	    $vmstate = PVE::QemuConfig->__snapshot_save_vmstate($vmid, $conf, "suspend-$date", $storecfg, $statestorage, 1);
>  	    $path = PVE::Storage::path($storecfg, $vmstate);
>  	    PVE::QemuConfig->write_config($vmid, $conf);
> -- 
> 2.20.1
> 
> 
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