Security-Enhanced Linux secures the nmbd processes via flexible mandatory access control.
If you want to allow users to resolve user passwd entries directly from ldap rather then using a sssd serve for the nmbd_t, you must turn on the authlogin_nsswitch_use_ldap boolean.
setsebool -P authlogin_nsswitch_use_ldap 1
If you want to allow confined applications to run with kerberos for the nmbd_t, you must turn on the kerberos_enabled boolean.
setsebool -P kerberos_enabled 1
You can see the context of a file using the -Z option to lsP 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.
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 directory.
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.
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:
Default Defined Ports: udp 137,138
You can see the context of a process using the -Z option to psP 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 PROCESS_TYPE can be used to make a process type permissive. Permissive process types are not denied access by SELinux. AVC messages will still be generated.
The SELinux user 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.
nmbd_var_run_t
/var/run/nmbd(/.*)?
/var/run/samba/nmbd(/.*)?
/var/run/samba/nmbd.pid
/var/run/samba/messages.tdb
/var/run/samba/namelist.debug
/var/run/samba/unexpected.tdb
samba_log_t
/var/log/samba(/.*)?
samba_var_t
/var/lib/samba(/.*)?
/var/cache/samba(/.*)?
/var/spool/samba(/.*)?
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
system-config-selinux is a GUI tool available to customize SELinux policy settings.