Re: [pve-devel] [PATCH v2 container 08/12] fix #2582: api: add checks for 'SuperUser' privilege for root-only options

["Fabian Grünbichler" <f.gruenbichler@proxmox.com>]

some more stuff:
- PVE::API2::LXC mentions root-only code paths in line 261
- message in PVE::LXC::Create mentions root in line 334

On March 11, 2022 12:25 pm, Oguz Bektas wrote:
> this way we can allow regular users to act as superuser on specific
> paths by giving them the (new) builtin 'SuperAdministrator' role or a
> custom role with the 'SuperUser' privilege
> 
> Signed-off-by: Oguz Bektas <o.bektas@proxmox.com>
> ---
> v1->v2:
> * update the messages to reflect superuser instead of root@pam
> 
> 
>  src/PVE/API2/LXC.pm        | 15 +++++++--------
>  src/PVE/API2/LXC/Config.pm |  2 +-
>  src/PVE/API2/LXC/Status.pm | 12 ++++++++----
>  src/PVE/LXC.pm             | 21 ++++++++++++---------
>  4 files changed, 28 insertions(+), 22 deletions(-)
> 
> diff --git a/src/PVE/API2/LXC.pm b/src/PVE/API2/LXC.pm
> index 84712f7..4631d0b 100644
> --- a/src/PVE/API2/LXC.pm
> +++ b/src/PVE/API2/LXC.pm
> @@ -304,7 +304,7 @@ __PACKAGE__->register_method({
>  
>  	my $conf = {};
>  
> -	my $is_root = $authuser eq 'root@pam';
> +	my $is_superuser = $authuser eq 'root@pam' || $rpcenv->check($authuser, "/vms/$vmid", ['SuperUser'], 1);

nit: line too long..

>  
>  	my $no_disk_param = {};
>  	my $mp_param = {};
> @@ -339,8 +339,8 @@ __PACKAGE__->register_method({
>  	    my $mp = $mountpoint->{mp};
>  
>  	    if ($mountpoint->{type} ne 'volume') { # bind or device
> -		die "Only root can pass arbitrary filesystem paths.\n"
> -		    if !$is_root;
> +		die "Only superusers can pass arbitrary filesystem paths.\n"
> +		    if !$is_superuser;
>  	    } else {
>  		my ($sid, $volname) = PVE::Storage::parse_volume_id($volid);
>  		&$check_and_activate_storage($sid);
> @@ -380,7 +380,7 @@ __PACKAGE__->register_method({

comment above this context line is still referencing root..

>  			# causing it to restore the raw lxc entries, among which there may be
>  			# 'lxc.idmap' entries. We need to make sure that the extracted contents
>  			# of the container match up with the restored configuration afterwards:
> -			$conf->{lxc} = $orig_conf->{lxc} if $is_root;
> +			$conf->{lxc} = $orig_conf->{lxc} if $is_superuser;
>  
>  			$conf->{unprivileged} = $orig_conf->{unprivileged}
>  			    if !defined($unprivileged) && defined($orig_conf->{unprivileged});
> @@ -414,8 +414,7 @@ __PACKAGE__->register_method({
>  				my $type = $mountpoint->{type};
>  				die "restoring rootfs to $type mount is only possible by specifying -rootfs manually!\n"
>  				    if ($ms eq 'rootfs');
> -				die "restoring '$ms' to $type mount is only possible for root\n"
> -				    if !$is_root;
> +				die "restoring '$ms' to $type mount is only possible for superusers\n" if !$is_superuser;
>  
>  				if ($mountpoint->{backup}) {
>  				    warn "WARNING - unsupported configuration!\n";
> @@ -456,7 +455,7 @@ __PACKAGE__->register_method({
>  
>  		    if ($restore) {
>  			print "merging backed-up and given configuration..\n";
> -			PVE::LXC::Create::restore_configuration($vmid, $storage_cfg, $archive, $rootdir, $conf, !$is_root, $unique, $skip_fw_config_restore);
> +			PVE::LXC::Create::restore_configuration($vmid, $storage_cfg, $archive, $rootdir, $conf, !$is_superuser, $unique, $skip_fw_config_restore);
>  			my $lxc_setup = PVE::LXC::Setup->new($conf, $rootdir);
>  			$lxc_setup->template_fixup($conf);
>  		    } else {
> @@ -2216,7 +2215,7 @@ __PACKAGE__->register_method({
>  	    raise_param_exc({ 'target-vmid' => $msg, 'storage' => $msg });
>  	} elsif ($target_vmid) {
>  	    $rpcenv->check_vm_perm($authuser, $target_vmid, undef, ['VM.Config.Disk'])
> -		if $authuser ne 'root@pam';
> +		if $authuser ne 'root@pam'; # no need to check for root@pam

why leave this one in and add a comment, but the others don't get the 
short cut? (e.g., there are two plain rpcenv->check calls jumping out 
even when just looking at the location of this change!)

>  
>  	    if ($vmid eq $target_vmid) {
>  		my $msg = "must be different than source VMID to move disk to another container";
> diff --git a/src/PVE/API2/LXC/Config.pm b/src/PVE/API2/LXC/Config.pm
> index 1fec048..6278b8a 100644
> --- a/src/PVE/API2/LXC/Config.pm
> +++ b/src/PVE/API2/LXC/Config.pm
> @@ -99,7 +99,7 @@ __PACKAGE__->register_method({
>      description => "Set container options.",
>      permissions => {
>  	check => ['perm', '/vms/{vmid}', $vm_config_perm_list, any => 1],
> -	description => 'non-volume mount points in rootfs and mp[n] are restricted to root@pam',
> +	description => 'non-volume mount points in rootfs and mp[n] are restricted to superusers',
>      },
>      parameters => {
>  	additionalProperties => 0,
> diff --git a/src/PVE/API2/LXC/Status.pm b/src/PVE/API2/LXC/Status.pm
> index f7e3128..92e37f8 100644
> --- a/src/PVE/API2/LXC/Status.pm
> +++ b/src/PVE/API2/LXC/Status.pm
> @@ -150,9 +150,11 @@ __PACKAGE__->register_method({
>  	my $node = extract_param($param, 'node');
>  	my $vmid = extract_param($param, 'vmid');
>  
> +	my $is_superuser = $authuser eq 'root@pam' || $rpcenv->check($authuser, "/vms/$vmid", ['SuperUser'], 1);

you can guess the nit ;)

> +
>  	my $skiplock = extract_param($param, 'skiplock');
> -	raise_param_exc({ skiplock => "Only root may use this option." })
> -	    if $skiplock && $authuser ne 'root@pam';
> +	raise_param_exc({ skiplock => "Only superusers may use this option." })
> +	    if $skiplock && !$is_superuser;
>  
>  	die "CT $vmid already running\n" if PVE::LXC::check_running($vmid);
>  
> @@ -234,9 +236,11 @@ __PACKAGE__->register_method({
>  	my $node = extract_param($param, 'node');
>  	my $vmid = extract_param($param, 'vmid');
>  
> +	my $is_superuser = $authuser eq 'root@pam' || $rpcenv->check($authuser, "/vms/$vmid", ['SuperUser'], 1);

same

> +
>  	my $skiplock = extract_param($param, 'skiplock');
> -	raise_param_exc({ skiplock => "Only root may use this option." })
> -	    if $skiplock && $authuser ne 'root@pam';
> +	raise_param_exc({ skiplock => "Only superusers may use this option." })
> +	    if $skiplock && !$is_superuser;
>  
>  	die "CT $vmid not running\n" if !PVE::LXC::check_running($vmid);
>  
> diff --git a/src/PVE/LXC.pm b/src/PVE/LXC.pm
> index b07d986..60c4fce 100644
> --- a/src/PVE/LXC.pm
> +++ b/src/PVE/LXC.pm
> @@ -1254,7 +1254,10 @@ sub template_create {
>  sub check_ct_modify_config_perm {
>      my ($rpcenv, $authuser, $vmid, $pool, $oldconf, $newconf, $delete, $unprivileged) = @_;
>  
> -    return 1 if $authuser eq 'root@pam';
> +    return 1 if $authuser eq 'root@pam'; # early exit for root@pam
> +
> +    my $is_superuser = $rpcenv->check($authuser, "/vms/$vmid", ['SuperUser'], 1);
> +
>      my $storage_cfg = PVE::Storage::config();
>  
>      my $check = sub {
> @@ -1265,8 +1268,8 @@ sub check_ct_modify_config_perm {
>  	    $rpcenv->check_vm_perm($authuser, $vmid, $pool, ['VM.Config.Disk']);
>  	    return if $delete;
>  	    my $data = PVE::LXC::Config->parse_volume($opt, $newconf->{$opt});
> -	    raise_perm_exc("mount point type $data->{type} is only allowed for root\@pam")
> -		if $data->{type} ne 'volume';
> +	    raise_perm_exc("mount point type $data->{type} is only allowed for superusers")
> +		if $data->{type} ne 'volume' && !$is_superuser;
>  	    my $volid = $data->{volume};
>  	    if ($volid =~ $NEW_DISK_RE) {
>  		my $sid = $1;
> @@ -1280,8 +1283,8 @@ sub check_ct_modify_config_perm {
>  		 $opt eq 'searchdomain' || $opt eq 'hostname') {
>  	    $rpcenv->check_vm_perm($authuser, $vmid, $pool, ['VM.Config.Network']);
>  	} elsif ($opt eq 'features') {
> -	    raise_perm_exc("changing feature flags for privileged container is only allowed for root\@pam")
> -		if !$unprivileged;
> +	    raise_perm_exc("changing feature flags for privileged container is only allowed for superusers")
> +		if !$unprivileged && !$is_superuser;
>  
>  	    my $nesting_changed = 0;
>  	    my $other_changed = 0;
> @@ -1319,13 +1322,13 @@ sub check_ct_modify_config_perm {
>  		    $other_changed = 1;
>  		}
>  	    }
> -	    raise_perm_exc("changing feature flags (except nesting) is only allowed for root\@pam")
> -		if $other_changed;
> +	    raise_perm_exc("changing feature flags (except nesting) is only allowed for superusers")
> +		if $other_changed && !$is_superuser;
>  	    $rpcenv->check_vm_perm($authuser, $vmid, $pool, ['VM.Allocate'])
>  		if $nesting_changed;
>  	} elsif ($opt eq 'hookscript') {
> -	    # For now this is restricted to root@pam
> -	    raise_perm_exc("changing the hookscript is only allowed for root\@pam");
> +	    raise_perm_exc("changing the hookscript is only allowed for superusers")
> +		if !$is_superuser;
>  	} else {
>  	    $rpcenv->check_vm_perm($authuser, $vmid, $pool, ['VM.Config.Options']);
>  	}
> -- 
> 2.30.2
> 
> 
> 
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