getfacl tips — authorized ACL-read literacy

Snapshot

Tip checklist (authorized only)

1. Confirm you may run getfacl on the lab host (syllabus box you own or were given access to; acl package required).
2. Prefer documenting who / why / ticket before any recursive ACL walk — never poke production without change control.
3. Record short factual notes; quote short Evidence (user/group names, masks — never secrets or foreign path dumps you should not see).
4. Optional: write peer → setfacl-tips.
5. Optional: mode peer → chmod-tips / ownership peer → chown-tips.
6. Prefer disposable lab paths for getfacl drills; quote non-secret ACL lines afterward as Evidence.
7. Prefer read-only getfacl / getfacl -c for most Evidence binders — avoid inventing ACL-bypass cookbooks.
8. Stop at literacy — no attack or unauthorized ACL-enumeration cookbooks.

Allowed framing

• Classroom labs reviewing getfacl / getfacl -R / getfacl -d on authorized disposable paths.
• Binding short factual notes as Evidence (user/group/mask — no secrets).
• Documenting expected vs observed ACL state for authorized inventory notes.
• Comparing getfacl ↔ setfacl / chmod / chown / namei peer tip pages under one binder.
• Testing default-ACL (-d) reads only when the syllabus authorizes that drill on lab resources.

Scope we will not cover

• No crack/pirate/keygen via getfacl.
• No intentional unauthorized ACL dumps against foreign hosts.
• No secret-theft or user-map harvesting via ACL walks on hosts you do not own.
• No cookbooks that weaken ACL isolation or clear masks on foreign paths without authorization.

Beginner path (authorized only)

1. Obtain one syllabus-approved disposable lab host with the acl tools available.
2. Prefer a throwaway lab directory before any recursive walk.
3. With authorization, run getfacl labdir; quote non-secret user/group/mask labels as Evidence.
4. Optional: peer tip pages above when the syllabus asks.
5. Stop at literacy — no attack or unauthorized ACL-enumeration cookbooks.

Practical notes for authorized labs

• getfacl reads POSIX ACLs — keep Evidence labels distinct from classic chmod-tips mode bits.
• Pair with setfacl-tips only for syllabus-approved ACL write literacy on lab paths.
• Recursive dumps may embed sensitive path names — never paste secrets into notes or git.
• Prefer documenting user/group names and masks the syllabus authorized without dumping full privileged inspect JSON.
• Never commit getfacl dumps with secrets to git — even for labs.

FAQ-aligned refusals (quick)

• Foreign-host ACL dumps → refuse.
• Unauthorized ACL-bypass / isolation-weaken cookbooks → refuse.
• Attack/credential-theft framing → refuse.

For legal, authorized and educational use only.

FAQ

Sources