,S,E,LINUX ,SECURITY-,ENHANCED ,LINUX IS THE MANDATORY-ACCESS-CONTROL LAYER THE ,,NSA OPEN-SOURCED INTO THE KERNEL3 BORN OF THE AGENCY'S ,,FLUX_/,,FLASK RESEARCH PROTOTYPES1 RELEASED UNDER THE ,,GPL IN ,DECEMBER #BJJJ1 AND MERGED MAINLINE DURING THE #B4E#B4F DEVELOPMENT SERIES "<@9#BJJC">4 ,WHERE ,UNIX PERMISSIONS ASK 8WHO OWNS THIS FILE AND WHAT DO THE BITS SAY10 ,S,E,LINUX ASKS 8WHAT IS THIS PROCESS'S CONTEXT1 AND DOES POLICY GRANT THIS EXACT OPERATION0 A WEB SERVER LABELED HTTPD.-T CAN'T READ _/ETC_/SHADOW EVEN IF A BUG GIVES IT ROOT1 BECAUSE NO RULE IN THE POLICY SAYS IT MAY4 ,LABELS1 NOT PATHS ,EVERY SUBJECT " AND OBJECT " CARRIES A SECURITY CONTEXT USER3ROLE3TYPE3LEVEL1 DISPLAYED BY LS -;,Z AND PS -;,Z4 ,POLICY COMPILES TYPE-ENFORCEMENT RULES " INTO A BINARY DATABASE THE KERNEL CONSULTS ON EVERY ACCESS2 DENIALS LAND IN THE AUDIT LOG AS ,,AVC MESSAGES4 ,DISTRIBUTIONS SHIP POLICIES TARGETED " IS THE ,FEDORA_/,,RHEL DEFAULT1 STRICT AND MLS EXIST FOR HIGH-ASSURANCE WORK4 ,THE DAILY TOOLS3 SESTATUS1 GETENFORCE_/SETENFORCE1 SEMANAGE1 RESTORECON1 AUDIT#B;ALLOW4 ,THE HONEST REPUTATION ,S,E,LINUX EARNED A REPUTATION FOR HOSTILITY THE CLASSIC ADMIN FIX OF 8SETENFORCE #J0 IS FAMOUS ENOUGH TO BE A JOKE BUT MODERN TARGETED POLICY PLUS AUDIT#B;ALLOW MAKES IT TRACTABLE1 AND ,ANDROID SHIPS IT ENFORCING ON EVERY PHONE3 BILLIONS OF DEVICES RUN ,,MAC WITHOUT KNOWING IT4 ,THE RIVAL IS ,APP,ARMOR "<,DEBIAN_/,UBUNTU_/,,SUSE'S PATH-BASED ANSWER SIMPLER1 WEAKER">2 THE SECURITY CHAPTER'S ,,MAC SECTION COMPARES BOTH4 ,SEE ALSO - ,LINUX ,SECURITY THE ,,MAC_/LEAST-PRIVILEGE CHAPTER - ,INSIDE A ,LINUX ,SYSTEM THE KERNEL LAYER IT HOOKS - ,PROCESSES THE SUBJECTS IT LABELS - ,LINUX NFTABLES ,,LUKS