Disable Mounting of squashfs

An XCCDF Rule

Description

To configure the system to prevent the squashfs kernel module from being loaded, add the following line to the file /etc/modprobe.d/squashfs.conf:

install squashfs /bin/true

This effectively prevents usage of this uncommon filesystem. The squashfs filesystem type is a compressed read-only Linux filesystem embedded in small footprint systems (similar to cramfs). A squashfs image can be used without having to first decompress the image.

Rationale

Removing support for unneeded filesystem types reduces the local attack surface of the system.

ID: xccdf_org.ssgproject.content_rule_kernel_module_squashfs_disabled
Severity: Low
References: 11 14 3 9

BAI10.01 BAI10.02 BAI10.03 BAI10.05 DSS05.02 DSS05.05 DSS06.06

3.4.6

4.3.3.5.1 4.3.3.5.2 4.3.3.5.3 4.3.3.5.4 4.3.3.5.5 4.3.3.5.6 4.3.3.5.7 4.3.3.5.8 4.3.3.6.1 4.3.3.6.2 4.3.3.6.3 4.3.3.6.4 4.3.3.6.5 4.3.3.6.6 4.3.3.6.7 4.3.3.6.8 4.3.3.6.9 4.3.3.7.1 4.3.3.7.2 4.3.3.7.3 4.3.3.7.4 4.3.4.3.2 4.3.4.3.3

SR 1.1 SR 1.10 SR 1.11 SR 1.12 SR 1.13 SR 1.2 SR 1.3 SR 1.4 SR 1.5 SR 1.6 SR 1.7 SR 1.8 SR 1.9 SR 2.1 SR 2.2 SR 2.3 SR 2.4 SR 2.5 SR 2.6 SR 2.7 SR 7.6

A.12.1.2 A.12.5.1 A.12.6.2 A.14.2.2 A.14.2.3 A.14.2.4 A.9.1.2

CM-6(a) CM-7(a) CM-7(b)

PR.IP-1 PR.PT-3

CCE-82717-0
Updated: about 1 year ago

---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
spec:
  config:
    ignition:      version: 3.1.0
    storage:
      files:
      - contents:
          source: data:,install%20squashfs%20/bin/true%0Ablacklist%20squashfs%0A
        mode: 0644
        path: /etc/modprobe.d/squashfs.conf
        overwrite: true

Disable Mounting of squashfs

Description

Rationale

Remediation - Kubernetes Patch