ksm_selinux(8)

💖 ksm_selinux(8) — SELinux Policy ksm 💖

Okay bestie, listen up ✨ this is the manual page for ksm_selinux(8) — aka the SELinux policy vibes for the ksm processes. It's giving security, it's giving mandatory access control, and honestly? It ate. Let's get into it 🎀

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🌸 NAME 🌸

ksm_selinux — Security Enhanced Linux Policy for the ksm processes. Periodt 💅

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🦋 DESCRIPTION 🦋

Security-Enhanced Linux secures the ksm processes via flexible mandatory access control. No cap, that's the whole vibe.

The ksm processes execute with the ksm_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 ksm_t

Go check your processes, bestie 👀

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✨ ENTRYPOINTS ✨

The ksm_t SELinux type can be entered via the ksm_exec_t file type.

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

/usr/libexec/ksmctl

That's the doorway, iykyk 🚪

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💜 PROCESS TYPES 💜

SELinux defines process types (domains) for each process running on the system. It's literally how it keeps things organized 🗂️

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

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

The following process types are defined for ksm:

• ksmtuned_t
• ksm_t

Note: semanage permissive -a ksm_t can be used to make the process type ksm_t permissive. SELinux does not deny access to permissive process types, but the AVC (SELinux denials) messages are still generated. So like, it's not a free pass, just a softer vibe check 😭

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🌈 BOOLEANS 🌈

SELinux policy is customizable based on least access required. ksm policy is extremely flexible and has several booleans that allow you to manipulate the policy and run ksm 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 allow all domains to execute in fips_mode, you must turn on the fips_mode boolean. Enabled by default.

setsebool -P fips_mode 1

These booleans are iconic, honestly 🫶

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🍓 MANAGED FILES 🍓

The SELinux process type ksm_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. So like, SELinux isn't doing everything for you, bestie 💅

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

root_t

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

sysfs_t

/sys(/.*)?

That's a whole lotta paths, but you got this 💪

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🧚 FILE CONTEXTS 🧚

SELinux requires files to have an extended attribute to define the file type. It's like a little name tag for 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 ksm policy is very flexible, allowing users to setup their ksm processes in as secure a method as possible.

STANDARD FILE CONTEXT

SELinux defines the file context types for the ksm. 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 ksmtuned_exec_t '/srv/ksm/content(/.*)?'
restorecon -R -v /srv/myksm_content

Note: SELinux often uses regular expressions to specify labels that match multiple files. Regex girlies rise 🙈

The following file types are defined for ksm:

• ksm_exec_t — Set files with the ksm_exec_t type, if you want to transition an executable to the ksm_t domain.
• ksm_unit_file_t — Set files with the ksm_unit_file_t type, if you want to treat the files as ksm unit content.
• ksmtuned_exec_t — Set files with the ksmtuned_exec_t type, if you want to transition an executable to the ksmtuned_t domain.
• ksmtuned_initrc_exec_t — Set files with the ksmtuned_initrc_exec_t type, if you want to transition an executable to the ksmtuned_initrc_t domain.
• ksmtuned_log_t — Set files with the ksmtuned_log_t type, if you want to treat the data as ksmtuned log data, usually stored under the /var/log directory.
• ksmtuned_unit_file_t — Set files with the ksmtuned_unit_file_t type, if you want to treat the files as ksmtuned unit content.
• ksmtuned_var_run_t — Set files with the ksmtuned_var_run_t type, if you want to store the ksmtuned files under the /run or /var/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. So like, chcon is a quick fix, but semanage fcontext + restorecon is the real glow-up 💅

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👑 COMMANDS 👑

semanage fcontext can also be used to manipulate default file context mappings. Slay.

semanage permissive can also be used to manipulate whether or not a process type is permissive. Iconic.

semanage module can also be used to enable/disable/install/remove policy modules. The way that this does everything 🔥

semanage boolean can also be used to manipulate the booleans. Boolean queen 👑

system-config-selinux is a GUI tool available to customize SELinux policy settings. For the visual learners, periodt 🎨

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⭐ AUTHOR ⭐

This manual page was auto-generated using sepolicy manpage. So like, not a human, but still cute 💖

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💫 SEE ALSO 💫

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

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And that's the whole manual page, bestie! You're now officially fluent in ksm_selinux. Go forth and SELinux responsibly 💅✨

Sign-off vibes: this was ksm manual, version 26-10-06, dated 26-10-06, and it's giving ksm_selinux(8) realness. Bye bestie! 🎀🦋