[pve-devel] [PATCH v4 qemu-server 06/18] api: allow SU privileged users to edit root-only options for VM configs

[Fabian Grünbichler]

On June 2, 2022 9:24 am, Oguz Bektas wrote:
> we now allow users with SU privilege to edit real device configurations
> for VMs.
> 
> they still need the required privilege to edit the corresponding
> configuration options (e.g. `VM.Config.HWType`), as well as the SU
> privilege.
> 
> Co-authored-by: Fabian Grünbichler <f.gruenbichler at proxmox.com>
> Signed-off-by: Oguz Bektas <o.bektas at proxmox.com>
> ---
> v3->v4:
> * added fabian's tag there as well since he helped me a lot with this part
> 
> 
>  PVE/API2/Qemu.pm | 62 ++++++++++++++++++++++++------------------------
>  1 file changed, 31 insertions(+), 31 deletions(-)
> 
> diff --git a/PVE/API2/Qemu.pm b/PVE/API2/Qemu.pm
> index 99b426e..2e75ab6 100644
> --- a/PVE/API2/Qemu.pm
> +++ b/PVE/API2/Qemu.pm
> @@ -545,16 +545,17 @@ my $cloudinitoptions = {
>  my $check_vm_create_serial_perm = sub {
>      my ($rpcenv, $authuser, $vmid, $pool, $param) = @_;
>  
> +    # no need to check permissions for root at pam
>      return 1 if $authuser eq 'root at pam';
>  
> +    my $is_superuser = $rpcenv->check($authuser, "/vms/$vmid", ['SuperUser'], 1);

this could switch to check_vm_perm if we want to extend the pool-based 
ACL to SU as well for VM creation. the vmid is not added to the pool yet 
at that point, so just checking /vms/$vmid doesn't work. but likely 
anybody who has superuser on a full pool and needs it to create 
superuser-restricted VMs already has superuser globally anyway, so not 
that important.

> +
>      foreach my $opt (keys %{$param}) {
>  	next if $opt !~ m/^serial\d+$/;
>  
> -	if ($param->{$opt} eq 'socket') {
> -	    $rpcenv->check_vm_perm($authuser, $vmid, $pool, ['VM.Config.HWType']);
> -	} else {
> -	    die "only root can set '$opt' config for real devices\n";
> -	}
> +	$rpcenv->check_vm_perm($authuser, $vmid, $pool, ['VM.Config.HWType']);
> +	die "only superusers can set '$opt' config for real devices\n"
> +	    if $param->{$opt} ne 'socket' && !$is_superuser;
>      }
>  
>      return 1;
> @@ -563,16 +564,17 @@ my $check_vm_create_serial_perm = sub {
>  my $check_vm_create_usb_perm = sub {
>      my ($rpcenv, $authuser, $vmid, $pool, $param) = @_;
>  
> +    # no need to check permissions for root at pam
>      return 1 if $authuser eq 'root at pam';
>  
> +    my $is_superuser = $rpcenv->check($authuser, "/vms/$vmid", ['SuperUser'], 1);

same here

> +
>      foreach my $opt (keys %{$param}) {
>  	next if $opt !~ m/^usb\d+$/;
>  
> -	if ($param->{$opt} =~ m/spice/) {
> -	    $rpcenv->check_vm_perm($authuser, $vmid, $pool, ['VM.Config.HWType']);
> -	} else {
> -	    die "only root can set '$opt' config for real devices\n";
> -	}
> +	$rpcenv->check_vm_perm($authuser, $vmid, $pool, ['VM.Config.HWType']);
> +	die "only superusers can set '$opt' config for real devices\n"
> +	    if $param->{$opt} !~ m/spice/ && !$is_superuser;
>      }
>  
>      return 1;
> @@ -581,8 +583,11 @@ my $check_vm_create_usb_perm = sub {
>  my $check_vm_modify_config_perm = sub {
>      my ($rpcenv, $authuser, $vmid, $pool, $key_list) = @_;
>  
> +    # no need to check permissions for root at pam
>      return 1 if $authuser eq 'root at pam';
>  
> +    my $is_superuser = $rpcenv->check($authuser, "/vms/$vmid", ['SuperUser'], 1);

and here

> +
>      foreach my $opt (@$key_list) {
>  	# some checks (e.g., disk, serial port, usb) need to be done somewhere
>  	# else, as there the permission can be value dependend
> @@ -618,7 +623,8 @@ my $check_vm_modify_config_perm = sub {
>  	} else {
>  	    # catches hostpci\d+, args, lock, etc.
>  	    # new options will be checked here
> -	    die "only root can set '$opt' config\n";
> +	    die "only superusers can set '$opt' config\n"
> +		if !$is_superuser;
>  	}
>      }
>  
> @@ -1328,6 +1334,8 @@ my $update_vm_api  = sub {
>  	push @paramarr, "-$key", $value;
>      }
>  
> +    my $is_superuser = $rpcenv->check($authuser, "/vms/$vmid", ['SuperUser'], 1);

but not here ;)

> +
>      my $skiplock = extract_param($param, 'skiplock');
>      raise_param_exc({ skiplock => "Only root may use this option." })
>  	if $skiplock && $authuser ne 'root at pam';
> @@ -1544,19 +1552,15 @@ my $update_vm_api  = sub {
>  		    PVE::QemuConfig->add_to_pending_delete($conf, $opt, $force);
>  		    PVE::QemuConfig->write_config($vmid, $conf);
>  		} elsif ($opt =~ m/^serial\d+$/) {
> -		    if ($val eq 'socket') {
> -			$rpcenv->check_vm_perm($authuser, $vmid, undef, ['VM.Config.HWType']);
> -		    } elsif ($authuser ne 'root at pam') {
> -			die "only root can delete '$opt' config for real devices\n";
> -		    }
> +		    $rpcenv->check_vm_perm($authuser, $vmid, undef, ['VM.Config.HWType']);
> +		    die "only superusers can delete '$opt' config for real devices\n"
> +			if $val ne 'socket' && !$is_superuser;
>  		    PVE::QemuConfig->add_to_pending_delete($conf, $opt, $force);
>  		    PVE::QemuConfig->write_config($vmid, $conf);
>  		} elsif ($opt =~ m/^usb\d+$/) {
> -		    if ($val =~ m/spice/) {
> -			$rpcenv->check_vm_perm($authuser, $vmid, undef, ['VM.Config.HWType']);
> -		    } elsif ($authuser ne 'root at pam') {
> -			die "only root can delete '$opt' config for real devices\n";
> -		    }
> +		    $rpcenv->check_vm_perm($authuser, $vmid, undef, ['VM.Config.HWType']);
> +		    die "only superusers can delete '$opt' config for real devices\n"
> +			if $val !~ m/spice/ && !$is_superuser;
>  		    PVE::QemuConfig->add_to_pending_delete($conf, $opt, $force);
>  		    PVE::QemuConfig->write_config($vmid, $conf);
>  		} else {
> @@ -1606,18 +1610,14 @@ my $update_vm_api  = sub {
>  			}
>  		    }
>  		} elsif ($opt =~ m/^serial\d+/) {
> -		    if ((!defined($conf->{$opt}) || $conf->{$opt} eq 'socket') && $param->{$opt} eq 'socket') {
> -			$rpcenv->check_vm_perm($authuser, $vmid, undef, ['VM.Config.HWType']);
> -		    } elsif ($authuser ne 'root at pam') {
> -			die "only root can modify '$opt' config for real devices\n";
> -		    }
> +		    $rpcenv->check_vm_perm($authuser, $vmid, undef, ['VM.Config.HWType']); # always check hw config

nit: that comment is not needed

> +		    die "only superusers can modify '$opt' config for real devices\n"
> +			if !$is_superuser && ((defined($conf->{$opt}) && $conf->{$opt} ne 'socket') || $param->{$opt} ne 'socket');
>  		    $conf->{pending}->{$opt} = $param->{$opt};
>  		} elsif ($opt =~ m/^usb\d+/) {
> -		    if ((!defined($conf->{$opt}) || $conf->{$opt} =~ m/spice/) && $param->{$opt} =~ m/spice/) {
> -			$rpcenv->check_vm_perm($authuser, $vmid, undef, ['VM.Config.HWType']);
> -		    } elsif ($authuser ne 'root at pam') {
> -			die "only root can modify '$opt' config for real devices\n";
> -		    }
> +		    $rpcenv->check_vm_perm($authuser, $vmid, undef, ['VM.Config.HWType']);
> +		    die "only superusers can modify '$opt' config for real devices\n"
> +			if !$is_superuser && ((defined($conf->{$opt}) && $conf->{$opt} !~ m/spice/) || $param->{$opt} !~ m/spice/);
>  		    $conf->{pending}->{$opt} = $param->{$opt};
>  		} else {
>  		    $conf->{pending}->{$opt} = $param->{$opt};
> -- 
> 2.30.2
> 
>