NAME¶

nmbd_selinux - Security Enhanced Linux Policy for the nmbd processes

DESCRIPTION¶

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

The nmbd processes execute with the nmbd_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 nmbd_t

ENTRYPOINTS¶

The nmbd_t SELinux type can be entered via the nmbd_exec_t file type.

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

/usr/bin/nmbd

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 nmbd policy is very flexible allowing users to setup their nmbd processes in as secure a method as possible.

The following process types are defined for nmbd:

nmbd_t

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

BOOLEANS¶

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

If you want to allow users to resolve user passwd entries directly from ldap rather then using a sssd server, you must turn on the authlogin_nsswitch_use_ldap boolean. Disabled by default.

setsebool -P authlogin_nsswitch_use_ldap 1

If you want to dontaudit all daemons scheduling requests (setsched, sys_nice), you must turn on the daemons_dontaudit_scheduling boolean. Enabled by default.

setsebool -P daemons_dontaudit_scheduling 1

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 confined applications to run with kerberos, you must turn on the kerberos_enabled boolean. Enabled by default.

setsebool -P kerberos_enabled 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

If you want to allow confined applications to use nscd shared memory, you must turn on the nscd_use_shm boolean. Enabled by default.

setsebool -P nscd_use_shm 1

If you want to allow samba to share any file/directory read only, you must turn on the samba_export_all_ro boolean. Disabled by default.

setsebool -P samba_export_all_ro 1

If you want to allow samba to share any file/directory read/write, you must turn on the samba_export_all_rw boolean. Disabled by default.

setsebool -P samba_export_all_rw 1

PORT TYPES¶

SELinux defines port types to represent TCP and UDP ports.

You can see the types associated with a port by using the following command:

semanage port -l

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

The following port types are defined for nmbd:

nmbd_port_t

Default Defined Ports: udp 137,138

MANAGED FILES¶

The SELinux process type nmbd_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.

cluster_conf_t

/etc/cluster(/.*)?

cluster_var_lib_t

/var/lib/pcsd(/.*)?
/var/lib/cluster(/.*)?
/var/lib/openais(/.*)?
/var/lib/pengine(/.*)?
/var/lib/corosync(/.*)?
/usr/lib/heartbeat(/.*)?
/var/lib/heartbeat(/.*)?
/var/lib/pacemaker(/.*)?

cluster_var_run_t

/run/crm(/.*)?
/run/cman_.*
/run/rsctmp(/.*)?
/run/aisexec.*
/run/heartbeat(/.*)?
/run/pcsd-ruby.socket
/run/corosync-qnetd(/.*)?
/run/corosync-qdevice(/.*)?
/run/pcsd.socket
/run/corosync.pid
/run/cpglockd.pid
/run/rgmanager.pid
/run/cluster/rgmanager.sk

ctdbd_var_lib_t

/var/lib/ctdb(/.*)?
/var/lib/ctdbd(/.*)?

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

nmbd_var_run_t

/run/nmbd(/.*)?
/run/samba/nmbd(/.*)?
/run/samba/nmbd.pid
/run/samba/messages.tdb
/run/samba/namelist.debug
/run/samba/unexpected.tdb

non_security_file_type

noxattrfs

all files on file systems which do not support extended attributes

root_t

/sysroot/ostree/deploy/.*-atomic/deploy(/.*)?
/
/initrd
/var/lib/ntp

samba_log_t

/var/log/samba(/.*)?

samba_var_t

/var/nmbd(/.*)?
/var/lib/samba(/.*)?
/var/cache/samba(/.*)?

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 nmbd policy is very flexible allowing users to setup their nmbd processes in as secure a method as possible.

STANDARD FILE CONTEXT

SELinux defines the file context types for the nmbd, 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 nmbd_exec_t '/srv/nmbd/content(/.*)?'
restorecon -R -v /srv/mynmbd_content

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

The following file types are defined for nmbd:

nmbd_exec_t

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

nmbd_var_run_t

- Set files with the nmbd_var_run_t type, if you want to store the nmbd files under the /run or /var/run directory.

Paths:

/run/nmbd(/.*)?, /run/samba/nmbd(/.*)?, /run/samba/nmbd.pid, /run/samba/messages.tdb, /run/samba/namelist.debug, /run/samba/unexpected.tdb

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 port can also be used to manipulate the port definitions

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), nmbd(8), semanage(8), restorecon(8), chcon(1), sepolicy(8), setsebool(8)