Disable Mounting of jffs2
Description
To configure the system to prevent the jffs2
kernel module from being loaded, add the following line to the file /etc/modprobe.d/jffs2.conf:
This effectively prevents usage of this uncommon filesystem.
Rationale
Linux kernel modules which implement filesystems that are not needed by the
local system should be disabled.
Shell script
The following script can be run on the host to remediate the issue.
#!/bin/bash
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then
if LC_ALL=C grep -q -m 1 "^install jffs2" /etc/modprobe.d/jffs2.conf ; then
sed -i 's#^install jffs2.*#install jffs2 /bin/false#g' /etc/modprobe.d/jffs2.conf
else
echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/jffs2.conf
echo "install jffs2 /bin/false" >> /etc/modprobe.d/jffs2.conf
fi
if ! LC_ALL=C grep -q -m 1 "^blacklist jffs2$" /etc/modprobe.d/jffs2.conf ; then
echo "blacklist jffs2" >> /etc/modprobe.d/jffs2.conf
fi
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Ansible playbook
The following playbook can be run with Ansible to remediate the issue.
- name: Ensure kernel module 'jffs2' is disabled
lineinfile:
create: true
dest: /etc/modprobe.d/jffs2.conf
regexp: install\s+jffs2
line: install jffs2 /bin/false
when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
tags:
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_jffs2_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
- name: Ensure kernel module 'jffs2' is blacklisted
lineinfile:
create: true
dest: /etc/modprobe.d/jffs2.conf
regexp: ^blacklist jffs2$
line: blacklist jffs2
when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
tags:
- NIST-800-171-3.4.6
- NIST-800-53-CM-6(a)
- NIST-800-53-CM-7(a)
- NIST-800-53-CM-7(b)
- disable_strategy
- kernel_module_jffs2_disabled
- low_complexity
- low_severity
- medium_disruption
- reboot_required
