inetd_selinux(8)

πŸ“¦
version 20250627+git412.dbf877ab7 Β· 7 versions
, in opensuse-leap 16.0

πŸ’– inetd_selinux: the glow-up guide to securing inetd πŸ’–

okay so bestie, you're here because you wanna understand inetd_selinux and honestly? same. this is the SELinux policy for the inetd processes and it's giving mandatory access control realness. let me break it down for you. πŸ’…


✨ DESCRIPTION ✨

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

The inetd processes execute with the inetd_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 inetd_t

πŸšͺ ENTRYPOINTS πŸšͺ

The inetd_t SELinux type can be entered via the inetd_exec_t file type.

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

/usr/bin/(x)?inetd, /usr/bin/rlinetd


πŸ‘‘ PROCESS TYPES πŸ‘‘

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

The following process types are defined for inetd:

inetd_t, inetd_child_t

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

  • daemons_dontaudit_scheduling β€” If you want to dontaudit all daemons scheduling requests (setsched, sys_nice), you must turn on this boolean. Enabled by default.
setsebool -P daemons_dontaudit_scheduling 1
  • deny_execmem β€” If you want to deny user domains applications to map a memory region as both executable and writable, you must turn on this boolean. This is dangerous and the executable should be reported in bugzilla. Disabled by default.
setsebool -P deny_execmem 1
  • mmap_low_allowed β€” 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 this boolean. Disabled by default.
setsebool -P mmap_low_allowed 1
  • nis_enabled β€” If you want to allow system to run with NIS, you must turn on this boolean. Disabled by default.
setsebool -P nis_enabled 1
  • secure_mode_insmod β€” If you want to disable kernel module loading, you must turn on this boolean. Disabled by default.
setsebool -P secure_mode_insmod 1
  • selinuxuser_execheap β€” If you want to allow unconfined executables to make their heap memory executable, you must turn on this boolean. 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. Disabled by default.
setsebool -P selinuxuser_execheap 1
  • selinuxuser_execstack β€” If you want to allow unconfined executables to make their stack executable, you must turn on this boolean. This should never, ever be necessary. Probably indicates a badly coded executable, but could indicate an attack. This executable should be reported in bugzilla. Disabled by default.
setsebool -P selinuxuser_execstack 1

πŸ”Œ PORT TYPES πŸ”Œ

SELinux defines port types to represent TCP and UDP ports.

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

The following port types are defined for inetd:

inetd_child_port_t

Default Defined Ports:

tcp 1,9,13,19,512,544,891,892,5666
udp 1,9,13,19,891,892

πŸ“ MANAGED FILES πŸ“

The SELinux process type inetd_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 β€” 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 ls.

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

🌸 STANDARD FILE CONTEXT 🌸

SELinux defines the file context types for the inetd. 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 inetd_exec_t '/srv/inetd/content(/.*)?'
restorecon -R -v /srv/myinetd_content
Note: SELinux often uses regular expressions to specify labels that match multiple files.

The following file types are defined for inetd:

inetd_child_exec_t

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

Paths:

/usr/bin/in..*d, /usr/lib/pysieved/pysieved.*.py,
/usr/local/lib/pysieved/pysieved.*.py, /usr/bin/identd

inetd_child_tmp_t

  • Set files with the inetd_child_tmp_t type, if you want to store inetd child temporary files in the /tmp directories.

inetd_child_var_run_t

  • Set files with the inetd_child_var_run_t type, if you want to store the inetd child files under the /run or /var/run directory.

inetd_exec_t

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

Paths:

/usr/bin/(x)?inetd, /usr/bin/rlinetd

inetd_log_t

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

inetd_tmp_t

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

inetd_var_run_t

  • Set files with the inetd_var_run_t type, if you want to store the inetd 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.

πŸ› οΈ COMMANDS πŸ› οΈ

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.


✍️ AUTHOR ✍️

This manual page was auto-generated using sepolicy manpage .


πŸ‘€ SEE ALSO πŸ‘€

selinux(8), inetd(8), semanage(8), restorecon(8), chcon(1), sepolicy(8), setsebool(8), inetd_child_selinux(8)


that's the whole vibe, bestie! πŸ’– this page was brought to you by the inetd manual, version 26-10-06, and the inetd_selinux(8) page. stay slay and secure out there! πŸ’…βœ¨πŸ¦‹

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