Security-Enhanced Linux secures the antivirus processes via flexible mandatory access control.
The antivirus processes execute with the antivirus_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 antivirus_t
The antivirus_t SELinux type can be entered via the antivirus_exec_t file type.
The default entrypoint paths for the antivirus_t domain are the following:
/usr/sbin/amavisd.*, /usr/sbin/amavi, /usr/sbin/clamd, /usr/bin/clamscan, /usr/bin/clamdscan, /usr/bin/freshclam, /usr/sbin/clamav-milter, /usr/lib/AntiVir/antivir
You can see the context of a process using the -Z option to psP Policy governs the access confined processes have to files. SELinux antivirus policy is very flexible allowing users to setup their antivirus processes in as secure a method as possible.
The following process types are defined for antivirus:
antivirus_t
Note: semanage permissive -a antivirus_t can be used to make the process type antivirus_t permissive. SELinux does not deny access to permissive process types, but the AVC (SELinux denials) messages are still generated.
If you want to determine whether antivirus programs can use JIT compiler, you must turn on the antivirus_use_jit boolean. Disabled by default.
setsebool -P antivirus_use_jit 1
If you want to allow users to resolve user passwd entries directly from ldap rather then using a sssd server, you must turn on the authlogin_nsswitch_use_ldap boolean. Disabled by default.
setsebool -P authlogin_nsswitch_use_ldap 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
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
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
If you want to allow confined applications to use nscd shared memory, you must turn on the nscd_use_shm boolean. Enabled by default.
setsebool -P nscd_use_shm 1
If you want to allow users to resolve user passwd entries directly from ldap rather then using a sssd server for the antivirus_t, you must turn on the authlogin_nsswitch_use_ldap boolean.
setsebool -P authlogin_nsswitch_use_ldap 1
If you want to allow confined applications to run with kerberos for the antivirus_t, you must turn on the kerberos_enabled boolean.
setsebool -P kerberos_enabled 1
The SELinux process type antivirus_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.
antivirus_db_t
/var/amavis(/.*)?
/var/clamav(/.*)?
/var/lib/clamd.*
/var/lib/amavis(/.*)?
/var/lib/clamav(/.*)?
/var/virusmails(/.*)?
/var/opt/f-secure(/.*)?
/var/spool/amavisd(/.*)?
/var/lib/clamav-unofficial-sigs(/.*)?
antivirus_home_t
antivirus_log_t
/var/log/clamd.*
/var/log/clamav.*
/var/log/freshclam.*
/var/log/amavisd.log.*
/var/log/clamav/freshclam.*
antivirus_tmp_t
antivirus_var_run_t
/var/run/clamd.*
/var/run/clamav.*
/var/run/amavis(d)?(/.*)?
/var/run/amavis(d)?/clamd.pid
/var/run/amavisd-snmp-subagent.pid
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
/var/run/crm(/.*)?
/var/run/cman_.*
/var/run/rsctmp(/.*)?
/var/run/aisexec.*
/var/run/heartbeat(/.*)?
/var/run/corosync-qnetd(/.*)?
/var/run/corosync-qdevice(/.*)?
/var/run/corosync.pid
/var/run/cpglockd.pid
/var/run/rgmanager.pid
/var/run/cluster/rgmanager.sk
root_t
/sysroot/ostree/deploy/.*-atomic/deploy(/.*)?
/
/initrd
snmpd_var_lib_t
/var/agentx(/.*)?
/var/net-snmp(/.*)
/var/lib/snmp(/.*)?
/var/net-snmp(/.*)?
/var/lib/net-snmp(/.*)?
/var/spool/snmptt(/.*)?
/usr/share/snmp/mibs/.index
systemd_passwd_var_run_t
/var/run/systemd/ask-password(/.*)?
/var/run/systemd/ask-password-block(/.*)?
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 antivirus policy is very flexible allowing users to setup their antivirus processes in as secure a method as possible.
EQUIVALENCE DIRECTORIES
antivirus policy stores data with multiple different file context types under the /var/lib/clamav directory. If you would like to store the data in a different directory you can use the semanage command to create an equivalence mapping. If you wanted to store this data under the /srv dirctory you would execute the following command:
semanage fcontext -a -e /var/lib/clamav /srv/clamav
restorecon -R -v /srv/clamav
antivirus policy stores data with multiple different file context types under the /var/run/amavis(d)? directory. If you would like to store the data in a different directory you can use the semanage command to create an equivalence mapping. If you wanted to store this data under the /srv dirctory you would execute the following command:
semanage fcontext -a -e /var/run/amavis(d)? /srv/amavis(d)?
restorecon -R -v /srv/amavis(d)?
STANDARD FILE CONTEXT
SELinux defines the file context types for the antivirus, if you wanted to store files with these types in a diffent paths, you need to execute the semanage command to sepecify alternate labeling and then use restorecon to put the labels on disk.
semanage fcontext -a -t antivirus_tmp_t '/srv/myantivirus_content(/.*)?'
restorecon -R -v /srv/myantivirus_content
Note: SELinux often uses regular expressions to specify labels that match multiple files.
The following file types are defined for antivirus:
antivirus_conf_t
- Set files with the antivirus_conf_t type, if you want to treat the files as antivirus configuration data, usually stored under the /etc directory.
antivirus_db_t
- Set files with the antivirus_db_t type, if you want to treat the files as antivirus database content.
antivirus_exec_t
- Set files with the antivirus_exec_t type, if you want to transition an executable to the antivirus_t domain.
antivirus_home_t
- Set files with the antivirus_home_t type, if you want to store antivirus files in the users home directory.
antivirus_initrc_exec_t
- Set files with the antivirus_initrc_exec_t type, if you want to transition an executable to the antivirus_initrc_t domain.
antivirus_log_t
- Set files with the antivirus_log_t type, if you want to treat the data as antivirus log data, usually stored under the /var/log directory.
antivirus_tmp_t
- Set files with the antivirus_tmp_t type, if you want to store antivirus temporary files in the /tmp directories.
antivirus_unit_file_t
- Set files with the antivirus_unit_file_t type, if you want to treat the files as antivirus unit content.
antivirus_var_run_t
- Set files with the antivirus_var_run_t type, if you want to store the antivirus 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.
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.