cyberstrikeus Ensure the default cgroup usage has been confirmed (Manual)
Profile Applicability
• Level 2 - Docker - Linux
Description
The --cgroup-parent option allows you to set the default cgroup parent to use for all containers. If there is no specific usage requirement for this, the setting should be left at its default.
Rationale
System administrators typically define cgroups under which containers are supposed to run. Even if cgroups are not explicitly defined by the system administrators, containers run under docker cgroup by default.
It is possible to attach to a different cgroup other than the one which is the default, however this type of usage should be monitored and confirmed because attaching to a different cgroup other than that is a default, it could be possible to share resources unevenly causing resource utilization problems on the host.
Impact
None.
Audit Procedure
In order to confirm this setting, the dockerd start-up options and any settings in /etc/docker/daemon.json should be reviewed.
To review the dockerd startup options, use:
grep "--cgroup-parent" /etc/docker/daemon.json
You should ensure that the --cgroup-parent parameter is either not set or is set as appropriate non-default cgroup.
The contents of /etc/docker/daemon.json should also be checked for this setting.
Remediation
The default setting is in line with good security practice and can be left in situ. If you wish to specifically set a non-default cgroup, pass the --cgroup-parent parameter to the Docker daemon when starting it.
For example,
dockerd --cgroup-parent=/foobar
Default Value
By default, docker daemon uses /docker for fs cgroup driver and system.slice for systemd cgroup driver.
References
CIS Controls
Controls Version: v8
Control: 6 Access Control Management
Use processes and tools to create, assign, manage, and revoke access credentials and privileges for user, administrator, and service accounts for enterprise assets and software.
IG 1: IG 2: IG 3:
Controls Version: v7
Control: 18 Application Software Security
Application Software Security