SYSTEMD_PCREXTEND_SELINUX(8)

📦
version 20250627+git412.dbf877ab7 · 6 versions
, in opensuse-leap 16.0

💅 NAME 💅

ok so bestie, welcome to systemd_pcrextend_selinux — the Security Enhanced Linux Policy for the systemd_pcrextend processes 🫶

(also this whole page lives in the systemd_...d_selinux(8) section of the manual, just so you know where you are ✨)

🦋 DESCRIPTION 🦋

Security-Enhanced Linux secures the systemd_pcrextend processes via flexible mandatory access control. fr fr, that's the whole vibe — SELinux is the bouncer at the club and it's checking everybody's labels 💅

The systemd_pcrextend processes execute with the systemd_pcrextend_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 systemd_pcrextend_t

look at her go 💖

🌸 ENTRYPOINTS 🌸

The systemd_pcrextend_t SELinux type can be entered via the systemd_pcrextend_exec_t file type.

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

/usr/lib/systemd/systemd-pcrextend

that's the door, that's the only door, periodt 🚪✨

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

The following process types are defined for systemd_pcrextend:

  • systemd_pcrextend_t
Note: semanage permissive -a systemd_pcrextend_t can be used to make the process type systemd_pcrextend_t permissive. SELinux does not deny access to permissive process types, but the AVC (SELinux denials) messages are still generated. so like... she's not gonna stop you, but she IS gonna write it down in her diary 💀📓

🎀 BOOLEANS 🎀

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

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

ngl three booleans and they're all vibes 🌈

🍓 MANAGED FILES 🍓

The SELinux process type systemd_pcrextend_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. (yes bestie, SELinux said "cool but do you have permission though" 😭)

  • 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
  • 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
  • syslogd_var_run_t
/run/log(/.*)?
/run/rsyslog(/.*)?
/run/syslog-ng.ctl
/run/syslog-ng(/.*)?
/run/systemd/journal(/.*)?
/run/systemd/journal.[^/]+(/.*)?
/run/metalog.pid
/run/syslogd.pid

like she said, those are the defaults, and she meant every single one 🧚💜

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

⭐ STANDARD FILE CONTEXT ⭐

SELinux defines the file context types for the systemd_pcrextend, 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 systemd_pcrextend_exec_t
'/srv/systemd_pcrextend/content(/.*)?'
restorecon -R -v /srv/mysystemd_pcrextend_content
Note: SELinux often uses regular expressions to specify labels that match multiple files. regex girlies stay winning 😌✨

The following file types are defined for systemd_pcrextend:

systemd_pcrextend_exec_t

  • Set files with the systemd_pcrextend_exec_t type, if you want to transition an executable to the systemd_pcrextend_t domain.
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 is cute, permanent is commitment 💀💖

🦋 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.

slay, that's your whole toolkit bestie 🎀

💜 AUTHOR 💜

This manual page was auto-generated using sepolicy manpage. (the robots wrote this one, not me, credit where credit is due 🤖✨)

🌈 SEE ALSO 🌈

okay that's the whole page, love u, go label something 🫶

this masterpiece is from systemd_pcrextend, version 26-10-06, dated 26-10-06, hanging out in the systemd_...d_selinux(8) manual section — mwah 💋👑

📦 where this page comes from