chronyd_selinux(8)

📦
version 20250627+git412.dbf877ab7 · 7 versions
, in opensuse-leap 16.0

💅 chronyd_selinux — the manual page, but make it cute

okay so bestie, the manual name is chronyd_selinux and this whole thing is the SELinux policy glow-up guide for chronyd processes. buckle up, it's actually iconic 🕐✨

✨ NAME ✨

chronyd_selinux — Security Enhanced Linux Policy for the chronyd processes. yes that's the whole name section, she's brief and she knows it 💅

🌸 DESCRIPTION 🌸

Security-Enhanced Linux secures the chronyd processes via flexible mandatory access control. lowkey the whole point. no cap.

The chronyd processes execute with the chronyd_t SELinux type. wanna check if you've got these processes running? just run the ps command with the -Z qualifier. easy.

For example:

ps -eZ | grep chronyd_t

🦋 ENTRYPOINTS 🦋

The chronyd_t SELinux type can be entered via the chronyd_exec_t file type. that's the doorway bestie 🚪

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

/usr/bin/chronyd, /usr/lib/chrony/helper, /usr/libexec/chrony-helper,
/usr/libexec/chrony/helper

👑 PROCESS TYPES 👑

SELinux defines process types (domains) for each process running on the system. every process gets its own lil identity, fr fr.

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

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

The following process types are defined for chronyd:

chronyd_t, chronyd_restricted_t
Note: semanage permissive -a chronyd_t can be used to make the process type chronyd_t permissive. SELinux does not deny access to permissive process types, but the AVC (SELinux denials) messages are still generated. so like, she won't block you, but she WILL be taking notes 📝😭

🎀 BOOLEANS 🎀

SELinux policy is customizable based on least access required. chronyd policy is extremely flexible and has several booleans that allow you to manipulate the policy and run chronyd with the tightest access possible. slay, granular control 💖

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

setsebool -P nis_enabled 1

🌈 PORT TYPES 🌈

SELinux defines port types to represent TCP and UDP ports. ports have vibes too, apparently 💅

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

The following port types are defined for chronyd:

chronyd_port_t

Default Defined Ports:

          udp 323

🧚 MANAGED FILES 🧚

The SELinux process type chronyd_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. don't forget the regular perms bestie, SELinux isn't a substitute for that 🙈

chronyd_tmp_t

chronyd_tmpfs_t

chronyd_var_lib_t

     /var/lib/chrony(/.*)?

chronyd_var_run_t

     /run/chrony(/.*)?
     /run/chronyd(/.*)?
     /run/chrony-dhcp(/.*)?
     /run/chrony-helper(/.*)?
     /run/chronyd.pid
     /run/chronyd.sock

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

gpsd_tmpfs_t

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

root_t

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

systemd_passwd_var_run_t

     /run/systemd/ask-password(/.*)?
     /run/systemd/ask-password-block(/.*)?

timemaster_tmpfs_t

⭐ FILE CONTEXTS ⭐

SELinux requires files to have an extended attribute to define the file type. it's giving "every file has a label era" 🏷️

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

💫 STANDARD FILE CONTEXT 💫

SELinux defines the file context types for the chronyd, 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. relabeling era, we love to see it 🫶

semanage fcontext -a -t chronyd_exec_t '/srv/chronyd/content(/.*)?'
restorecon -R -v /srv/mychronyd_content
Note: SELinux often uses regular expressions to specify labels that match multiple files. regex girlies rise 😭

The following file types are defined for chronyd:

chronyd_exec_t

  • Set files with the chronyd_exec_t type, if you want to transition an executable to the chronyd_t domain.

Paths:

     /usr/bin/chronyd, /usr/lib/chrony/helper, /usr/libexec/chrony-
     helper, /usr/libexec/chrony/helper

chronyd_initrc_exec_t

  • Set files with the chronyd_initrc_exec_t type, if you want to transition an executable to the chronyd_initrc_t domain.

chronyd_keys_t

  • Set files with the chronyd_keys_t type, if you want to treat the files as chronyd keys data.

chronyd_tmp_t

  • Set files with the chronyd_tmp_t type, if you want to store chronyd temporary files in the /tmp directories.

chronyd_tmpfs_t

  • Set files with the chronyd_tmpfs_t type, if you want to store chronyd files on a tmpfs file system.

chronyd_unit_file_t

  • Set files with the chronyd_unit_file_t type, if you want to treat the files as chronyd unit content.

chronyd_var_lib_t

  • Set files with the chronyd_var_lib_t type, if you want to store the chronyd files under the /var/lib directory.

chronyd_var_log_t

  • Set files with the chronyd_var_log_t type, if you want to treat the data as chronyd var log data, usually stored under the /var/log directory.

chronyd_var_run_t

  • Set files with the chronyd_var_run_t type, if you want to store the chronyd files under the /run or /var/run directory.

Paths:

     /run/chrony(/.*)?, /run/chronyd(/.*)?, /run/chrony-dhcp(/.*)?,
     /run/chrony-helper(/.*)?, /run/chronyd.pid, /run/chronyd.sock
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. temporary vs permanent, know the difference bestie 💀

🔥 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. yes, a GUI, for when the terminal is not the vibe today 🖱️✨

💜 AUTHOR 💜

This manual page was auto-generated using sepolicy manpage . — not me writing a whole essay by hand, the machine did it, and honestly? she ate 🤖💅

🌟 SEE ALSO 🌟

selinux(8), chronyd(8), semanage(8), restorecon(8), chcon(1), sepolicy(8), setsebool(8), chronyd_restricted_selinux(8)

and that's the whole page, bestie 🫶 this version came from chronyd dated 26-10-06, printed under the chronyd_selinux(8) banner — go forth and label responsibly, mwah 💖🎀

📦 where this page comes from