Security-Enhanced Linux secures the qmail_smtpd processes via flexible mandatory access control.
The qmail_smtpd processes execute with the qmail_smtpd_t SELinux type. You can check if you have these processes running by executing the ps command with the -Z qualifier.
ps -eZ | grep qmail_smtpd_t
The qmail_smtpd_t SELinux type can be entered via the qmail_smtpd_exec_t file type.
The default entrypoint paths for the qmail_smtpd_t domain are the following:
You can see the context of a process using the -Z option to psP Policy governs the access confined processes have to files. SELinux qmail_smtpd policy is very flexible allowing users to setup their qmail_smtpd processes in as secure a method as possible.
The following process types are defined for qmail_smtpd:
Note: semanage permissive -a qmail_smtpd_t can be used to make the process type qmail_smtpd_t permissive. SELinux does not deny access to permissive process types, but the AVC (SELinux denials) messages are still generated.
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 confined applications to run with kerberos, you must turn on the kerberos_enabled boolean. Enabled by default.
setsebool -P kerberos_enabled 1
You can see the context of a file using the -Z option to lsP Policy governs the access confined processes have to these files. SELinux qmail_smtpd policy is very flexible allowing users to setup their qmail_smtpd processes in as secure a method as possible.
The following file types are defined for qmail_smtpd:
- Set files with the qmail_smtpd_exec_t type, if you want to transition an executable to the qmail_smtpd_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.
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.