semanage_selinux - Man Page

Security Enhanced Linux Policy for the semanage processes

Description

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

The semanage processes execute with the semanage_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 semanage_t

Entrypoints

The semanage_t SELinux type can be entered via the semanage_exec_t file type.

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

/usr/bin/semanage, /usr/bin/semodule, /usr/libexec/selinux/selinux-autorelabel, /usr/libexec/selinux/semanage_migrate_store, /usr/share/system-config-selinux/selinux_server.py, /usr/share/system-config-selinux/system-config-selinux-dbus.py

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 psbP

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

The following process types are defined for semanage:

semanage_t

Note: semanage permissive -a semanage_t can be used to make the process type semanage_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.  semanage policy is extremely flexible and has several booleans that allow you to manipulate the policy and run semanage with the tightest access possible.

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 deny user domains applications to map a memory region as both executable and writable, this is dangerous and the executable should be reported in bugzilla, you must turn on the deny_execmem boolean. Disabled by default.

setsebool -P deny_execmem 1

If you want to control the ability to mmap a low area of the address space, as configured by /proc/sys/vm/mmap_min_addr, you must turn on the mmap_low_allowed boolean. Disabled by default.

setsebool -P mmap_low_allowed 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 disable kernel module loading, you must turn on the secure_mode_insmod boolean. Disabled by default.

setsebool -P secure_mode_insmod 1

If you want to allow unconfined executables to make their heap memory executable.  Doing this is a really bad idea. Probably indicates a badly coded executable, but could indicate an attack. This executable should be reported in bugzilla, you must turn on the selinuxuser_execheap boolean. Disabled by default.

setsebool -P selinuxuser_execheap 1

If you want to allow unconfined executables to make their stack executable.  This should never, ever be necessary. Probably indicates a badly coded executable, but could indicate an attack. This executable should be reported in bugzilla, you must turn on the selinuxuser_execstack boolean. Enabled by default.

setsebool -P selinuxuser_execstack 1

Managed Files

The SELinux process type semanage_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.

file_type

all files on the system

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 lsbP

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

EQUIVALENCE DIRECTORIES

semanage policy stores data with multiple different file context types under the /var/lib/selinux directory.  If you would like to store the data in a different directory you can use the semanage command to create an equivalence mapping.  If you wanted to store this data under the /srv directory you would execute the following command:

semanage fcontext -a -e /var/lib/selinux /srv/selinux
restorecon -R -v /srv/selinux

STANDARD FILE CONTEXT

SELinux defines the file context types for the semanage, 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 semanage_store_t '/srv/semanage/content(/.*)?'
restorecon -R -v /srv/mysemanage_content

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

The following file types are defined for semanage:

semanage_exec_t

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

Paths:

/usr/bin/semanage, /usr/bin/semodule, /usr/libexec/selinux/selinux-autorelabel, /usr/libexec/selinux/semanage_migrate_store, /usr/share/system-config-selinux/selinux_server.py, /usr/share/system-config-selinux/system-config-selinux-dbus.py

semanage_read_lock_t

- Set files with the semanage_read_lock_t type, if you want to treat the files as semanage read lock data, stored under the /var/lock directory

Paths:

/etc/selinux/([^/]*/)?modules/semanage.read.LOCK, /var/lib/selinux/[^/]+/semanage.read.LOCK

semanage_store_t

- Set files with the semanage_store_t type, if you want to treat the files as semanage store data.

Paths:

/etc/selinux/([^/]*/)?policy(/.*)?, /etc/selinux/([^/]*/)?modules/(active|tmp|previous)(/.*)?, /etc/selinux/(minimum|mls|targeted)/(active|tmp|previous)(/.*)?, /var/lib/selinux(/.*)?, /etc/share/selinux/mls(/.*)?, /etc/share/selinux/targeted(/.*)?

semanage_tmp_t

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

semanage_trans_lock_t

- Set files with the semanage_trans_lock_t type, if you want to treat the files as semanage trans lock data, stored under the /var/lock directory

Paths:

/etc/selinux/([^/]*/)?modules/semanage.trans.LOCK, /var/lib/selinux/[^/]+/semanage.trans.LOCK

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

Info

24-12-02 SELinux Policy semanage