chfn_selinux(8)

✨ chfn_selinux — the SELinux tea for chfn 💅

okay so bestie, welcome to chfn_selinux(8), the SELinux Policy chfn manual page 🎀 this is the whole glow-up guide to how SELinux handles the chfn processes, and honestly? it ate.

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🌸 NAME 🌸

chfn_selinux — Security Enhanced Linux Policy for the chfn processes. that's it, that's the vibe check 💖

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🦋 DESCRIPTION 🦋

Security-Enhanced Linux secures the chfn processes via flexible mandatory access control. yes, mandatory — SELinux is the main character and it does not take suggestions 😌

The chfn processes execute with the chfn_t SELinux type. wanna check if you've got these processes running? just run the ps command with the -Z qualifier, like:

ps -eZ | grep chfn_t

literally that simple, no cap 🫶

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🔥 ENTRYPOINTS 🔥

The chfn_t SELinux type can be entered via the chfn_exec_t file type. so that's the doorway, the portal, the little velvet rope ✨

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

/usr/bin/chfn, /usr/bin/chsh

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👑 PROCESS TYPES 👑

SELinux defines process types (domains) for each process running on the system. very organized of it, honestly 💅

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

Policy governs the access confined processes have to files. SELinux chfn policy is very flexible allowing users to setup their chfn processes in as secure a method as possible. flexible and secure, we love a multitasker 🌈

The following process types are defined for chfn:

chfn_t

Note: semanage permissive -a chfn_t can be used to make the process type chfn_t permissive. SELinux does not deny access to permissive process types, but the AVC (SELinux denials) messages are still generated. so like, it stops blocking you but it's still gonna gossip about it in the logs 🙈

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🍓 BOOLEANS 🍓

SELinux policy is customizable based on least access required. chfn policy is extremely flexible and has several booleans that allow you to manipulate the policy and run chfn with the tightest access possible. tightest access possible = the it-girl of security settings 💖

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

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🧚 MANAGED FILES 🧚

The SELinux process type chfn_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 — SELinux isn't out here doing everything for you, bestie 😭

faillog_t

/var/log/btmp.*
/run/faillock(/.*)?
/var/log/faillog.*
/var/log/tallylog.*

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

lastlog_t

/var/log/lastlog.*
/var/lib/lastlog(/.*)?

security_t

/selinux

wtmpdb_journal_t

/var/lib/wtmpdb/wtmp.db-journal

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💜 FILE CONTEXTS 💜

SELinux requires files to have an extended attribute to define the file type. it's giving "everything has a label, including your files" 🏷️✨

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 chfn policy is very flexible allowing users to setup their chfn processes in as secure a method as possible. (yes we said that twice, because it's true twice 💅)

⭐ STANDARD FILE CONTEXT ⭐

SELinux defines the file context types for the chfn, 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 chfn_exec_t '/srv/chfn/content(/.*)?'
restorecon -R -v /srv/mychfn_content

Note: SELinux often uses regular expressions to specify labels that match multiple files. regexes are iconic, we stan 🎀

The following file types are defined for chfn:

• chfn_exec_t — Set files with the chfn_exec_t type, if you want to transition an executable to the chfn_t domain.

Paths:

/usr/bin/chfn, /usr/bin/chsh

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 😤

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🫶 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. a whole GUI, for the girlies who like buttons 🌸

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🌈 AUTHOR 🌈

This manual page was auto-generated using sepolicy manpage. not me being auto-generated and still serving looks 💀✨

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💖 SEE ALSO 💖

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

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and that's the whole page, bestie 🦋 this one's chfn on 26-10-06, filed under chfn_selinux(8) — go forth and label responsibly, ily, mwah 💜🎀