nbdkit_selinux

NAME
DESCRIPTION
ENTRYPOINTS
PROCESS TYPES
MCS Constrained
BOOLEANS
MANAGED FILES
FILE CONTEXTS
COMMANDS
AUTHOR
SEE ALSO

NAME

nbdkit_selinux − Security Enhanced Linux Policy for the nbdkit processes

DESCRIPTION

Security-Enhanced Linux secures the nbdkit processes via flexible mandatory access control.

The nbdkit processes execute with the nbdkit_t SELinux type. You can check if you have these processes running by executing the ps command with the −Z qualifier.

For example:

ps -eZ | grep nbdkit_t

ENTRYPOINTS

The nbdkit_t SELinux type can be entered via the nbdkit_exec_t file type.

The default entrypoint paths for the nbdkit_t domain are the following:

/usr/sbin/nbdkit

PROCESS TYPES

SELinux defines process types (domains) for each process running on the system

You can see the context of a process using the −Z option to ps

Policy governs the access confined processes have to files. SELinux nbdkit policy is very flexible allowing users to setup their nbdkit processes in as secure a method as possible.

The following process types are defined for nbdkit:

nbdkit_t

Note: semanage permissive -a nbdkit_t can be used to make the process type nbdkit_t permissive. SELinux does not deny access to permissive process types, but the AVC (SELinux denials) messages are still generated.

MCS Constrained

The SELinux process type nbdkit_t is an MCS (Multi Category Security) constrained type. Sometimes this separation is referred to as sVirt. These types are usually used for securing multi-tenant environments, such as virtualization, containers or separation of users. The tools used to launch MCS types, pick out a different MCS label for each process group.

For example one process might be launched with nbdkit_t:s0:c1,c2, and another process launched with nbdkit_t:s0:c3,c4. The SELinux kernel only allows these processes can only write to content with a matching MCS label, or a MCS Label of s0. A process running with the MCS level of s0:c1,c2 is not allowed to write to content with the MCS label of s0:c3,c4

BOOLEANS

SELinux policy is customizable based on least access required. nbdkit policy is extremely flexible and has several booleans that allow you to manipulate the policy and run nbdkit with the tightest access possible.

If you want to allow all domains to execute in fips_mode, you must turn on the fips_mode boolean. Enabled by default.

setsebool -P fips_mode 1

If you want to allow system to run with NIS, you must turn on the nis_enabled boolean. Disabled by default.

setsebool -P nis_enabled 1

MANAGED FILES

The SELinux process type nbdkit_t can manage files labeled with the following file types. The paths listed are the default paths for these file types. Note the processes UID still need to have DAC permissions.

krb5_host_rcache_t

/var/tmp/krb5_0.rcache2
/var/cache/krb5rcache(/.*)?
/var/tmp/nfs_0
/var/tmp/DNS_25
/var/tmp/host_0
/var/tmp/imap_0
/var/tmp/HTTP_23
/var/tmp/HTTP_48
/var/tmp/ldap_55
/var/tmp/ldap_487
/var/tmp/ldapmap1_0

nbdkit_home_t

/home/[^/]+/tmp(/.*)?

nbdkit_tmp_t

svirt_image_t

FILE CONTEXTS

SELinux requires files to have an extended attribute to define the file type.

You can see the context of a file using the −Z option to ls

Policy governs the access confined processes have to these files. SELinux nbdkit policy is very flexible allowing users to setup their nbdkit processes in as secure a method as possible.

STANDARD FILE CONTEXT

SELinux defines the file context types for the nbdkit, if you wanted to store files with these types in a different paths, you need to execute the semanage command to specify alternate labeling and then use restorecon to put the labels on disk.

semanage fcontext -a -t nbdkit_unit_file_t ’/srv/mynbdkit_content(/.*)?’
restorecon -R -v /srv/mynbdkit_content

Note: SELinux often uses regular expressions to specify labels that match multiple files.

The following file types are defined for nbdkit:

nbdkit_exec_t

- Set files with the nbdkit_exec_t type, if you want to transition an executable to the nbdkit_t domain.

nbdkit_home_t

- Set files with the nbdkit_home_t type, if you want to store nbdkit files in the users home directory.

nbdkit_tmp_t

- Set files with the nbdkit_tmp_t type, if you want to store nbdkit temporary files in the /tmp directories.

nbdkit_unit_file_t

- Set files with the nbdkit_unit_file_t type, if you want to treat the files as nbdkit unit content.

Note: File context can be temporarily modified with the chcon command. If you want to permanently change the file context you need to use the semanage fcontext command. This will modify the SELinux labeling database. You will need to use restorecon to apply the labels.

COMMANDS

semanage fcontext can also be used to manipulate default file context mappings.

semanage permissive can also be used to manipulate whether or not a process type is permissive.

semanage module can also be used to enable/disable/install/remove policy modules.

semanage boolean can also be used to manipulate the booleans

system-config-selinux is a GUI tool available to customize SELinux policy settings.

AUTHOR

This manual page was auto-generated using sepolicy manpage .

SEE ALSO

selinux(8), nbdkit(8), semanage(8), restorecon(8), chcon(1), sepolicy(8), setsebool(8)