exim_selinux(8) - Linux man page

Name

exim_selinux - Security Enhanced Linux Policy for the exim processes

Description

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

The exim processes execute with the exim_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 exim_t

Entrypoints

The exim_t SELinux type can be entered via the "exim_exec_t" file type. The default entrypoint paths for the exim_t domain are the following:"

/usr/sbin/exim[0-9]?

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

The following process types are defined for exim:

exim_t

Note: semanage permissive -a exim_t

can be used to make the process type exim_t permissive. Permissive process types are not denied access by SELinux. AVC messages will still be generated.

Booleans

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

If you want to allow exim to connect to databases (postgres, mysql), you must turn on the exim_can_connect_db boolean.

setsebool -P exim_can_connect_db 1

If you want to allow exim to create, read, write, and delete unprivileged user files, you must turn on the exim_manage_user_files boolean.

setsebool -P exim_manage_user_files 1

If you want to allow exim to read unprivileged user files, you must turn on the exim_read_user_files boolean.

setsebool -P exim_read_user_files 1

If you want to allow exim to connect to databases (postgres, mysql), you must turn on the exim_can_connect_db boolean.

setsebool -P exim_can_connect_db 1

If you want to allow exim to create, read, write, and delete unprivileged user files, you must turn on the exim_manage_user_files boolean.

setsebool -P exim_manage_user_files 1

If you want to allow exim to read unprivileged user files, you must turn on the exim_read_user_files boolean.

setsebool -P exim_read_user_files 1

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

The following file types are defined for exim:

exim_exec_t

- Set files with the exim_exec_t type, if you want to transition an executable to the exim_t domain.

exim_initrc_exec_t

- Set files with the exim_initrc_exec_t type, if you want to transition an executable to the exim_initrc_t domain.

exim_keytab_t

- Set files with the exim_keytab_t type, if you want to treat the files as kerberos keytab files.

exim_log_t

- Set files with the exim_log_t type, if you want to treat the data as exim log data, usually stored under the /var/log directory.

exim_spool_t

- Set files with the exim_spool_t type, if you want to store the exim files under the /var/spool directory.

exim_tmp_t

- Set files with the exim_tmp_t type, if you want to store exim temporary files in the /tmp directories.

exim_var_run_t

- Set files with the exim_var_run_t type, if you want to store the exim files under the /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.

Managed Files

The SELinux process type exim_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.

arpwatch_tmp_t

dovecot_spool_t

/var/spool/dovecot(/.*)?

exim_log_t

/var/log/exim[0-9]?(/.*)?

exim_spool_t

/var/spool/exim[0-9]?(/.*)?

exim_tmp_t
exim_var_run_t

/var/run/exim[0-9]?.pid

initrc_tmp_t
mail_home_rw_t

/root/Maildir(/.*)?

/home/[^/]*/Maildir(/.*)?

mail_spool_t

/var/mail(/.*)?

/var/spool/imap(/.*)?

/var/spool/mail(/.*)?

mnt_t

/mnt(/[^/]*)

/mnt(/[^/]*)?

/rhev(/[^/]*)?

/media(/[^/]*)

/media(/[^/]*)?

/etc/rhgb(/.*)?

/media/.hal-.*

/net

/afs

/misc

/rhev

nfs_t
root_t

/initrd

sendmail_tmp_t
tmp_t

/tmp

/usr/tmp

/var/tmp

/var/tmp/vi.recover

user_home_t

/home/[^/]*/.+

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.

Author

This manual page was auto-generated using sepolicy manpage by mgrepl.