What it means
Linux Security Modules provide a common kernel framework for mandatory access-control and other security mechanisms that enforce policy beyond traditional user and group permissions.
Why it matters
Discretionary permissions alone cannot express every containment requirement; kernel-enforced policy can limit damage even after an account or process is compromised.
Practical focus
- Define the kernel-enforced policies required by each workload and the security outcome it must support
- Apply an approved Linux Security Module with documented enforcement and exception handling through documented, reviewable configuration
- Verify policy decisions, denials, labels, and enforcement mode after changes and on a scheduled basis
- Plan for a policy change blocking a legitimate service or failing open, including rollback, ownership, and escalation
Common mistakes
- Enabling a feature without defining what it should protect
- Relying on defaults or one-time validation
- Granting broad exceptions that erase the control boundary
- Treating a policy change blocking a legitimate service or failing open as an operational surprise instead of a test case
Certification relevance
This subject appears in or supports the following certification bodies of knowledge: