{"id":78684,"date":"2026-05-30T23:38:22","date_gmt":"2026-05-30T23:38:22","guid":{"rendered":"http:\/\/bangla.sitestree.com\/?p=78684"},"modified":"2026-05-30T23:38:22","modified_gmt":"2026-05-30T23:38:22","slug":"define-and-describe-selinux-in-general-terms","status":"publish","type":"post","link":"http:\/\/bangla.sitestree.com\/?p=78684","title":{"rendered":"Define and describe Selinux in general terms"},"content":{"rendered":"\n

SELinux<\/strong> stands for Security-Enhanced Linux<\/strong>.<\/p>\n\n\n\n

It is a Linux security system that adds an extra layer of protection to the operating system. It controls what users, programs, services, and processes<\/strong> are allowed to do.<\/p>\n\n\n\n

A simple definition:<\/p>\n\n\n\n

\n

SELinux is a security feature in Linux that enforces strict rules about which processes can access which files, directories, ports, and system resources.<\/strong><\/p>\n<\/blockquote>\n\n\n\n

General idea<\/h2>\n\n\n\n

Normal Linux permissions ask:<\/p>\n\n\n\n

Does this user have permission to access this file?\n<\/code><\/pre>\n\n\n\n
SELinux asks an additional question:<\/p>\n\n\n\n
Is this process allowed by security policy to access this object?\n<\/code><\/pre>\n\n\n\n
So even if normal file permissions allow access, SELinux can still block it.<\/p>\n\n\n\n
Example<\/h2>\n\n\n\n
Suppose Apache web server tries to read:<\/p>\n\n\n\n
\/var\/www\/html\/index.html\n<\/code><\/pre>\n\n\n\n
Normal permissions may allow it:<\/p>\n\n\n\n
-rw-r--r--\n<\/code><\/pre>\n\n\n\n
But SELinux also checks the file\u2019s security label. If the file has the wrong SELinux label, Apache may be denied access.<\/p>\n\n\n\n
Example command:<\/p>\n\n\n\n
ls -Z \/var\/www\/html\/index.html\n<\/code><\/pre>\n\n\n\n
This shows SELinux security context labels.<\/p>\n\n\n\n
Why SELinux is useful<\/h2>\n\n\n\n
SELinux helps protect the system if a service is misconfigured or compromised.<\/p>\n\n\n\n
For example, if a web server is attacked, SELinux can limit what the web server process is allowed to access. The attacker may control the web server process, but SELinux can still prevent it from reading unrelated system files.<\/p>\n\n\n\n
Common SELinux modes<\/h2>\n\n\n\n
getenforce\n<\/code><\/pre>\n\n\n\n
Possible outputs:<\/p>\n\n\n\n
Enforcing\nPermissive\nDisabled\n<\/code><\/pre>\n\n\n\n
Mode<\/th>Meaning<\/th><\/tr><\/thead>
Enforcing<\/code><\/td>SELinux policy is active and blocks unauthorized actions<\/td><\/tr>
Permissive<\/code><\/td>SELinux does not block, but logs warnings<\/td><\/tr>
Disabled<\/code><\/td>SELinux is turned off<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
Slide-friendly summary<\/h2>\n\n\n\n
\n
SELinux is a mandatory access control system for Linux. It uses security policies and labels to control what processes can access. It provides extra protection beyond normal Linux permissions.<\/strong><\/p>\n<\/blockquote>\n\n\n\n
<\/p>\n\n\n\n
REF: AI Tools\/ChatGPT<\/p>\n","protected":false},"excerpt":{"rendered":"
SELinux stands for Security-Enhanced Linux. It is a Linux security system that adds an extra layer of protection to the operating system. It controls what users, programs, services, and processes are allowed to do. A simple definition: SELinux is a security feature in Linux that enforces strict rules about which processes can access which files, … <\/p>\n
Continue reading<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":false},"categories":[1976],"tags":[],"class_list":["post-78684","post","type-post","status-publish","format-standard","hentry","category-anything-linux","item-wrap"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack-related-posts":[{"id":78678,"url":"http:\/\/bangla.sitestree.com\/?p=78678","url_meta":{"origin":78684,"position":0},"title":"Linux: ACL vs Selinux","author":"Sayed","date":"May 30, 2026","format":false,"excerpt":"ACL vs SELinux ACL and SELinux both control access, but they work at different levels. FeatureACLSELinuxFull nameAccess Control ListSecurity-Enhanced LinuxMain purposeGive extra file permissions to specific users\/groupsEnforce system-wide security policyAccess modelDAC: Discretionary Access ControlMAC: Mandatory Access ControlControlled byFile owner\/rootSELinux policy\/rootWorks onFiles\/directoriesFiles, processes, ports, services, usersCommon commandsgetfacl, setfaclgetenforce, ls -Z, semanage,\u2026","rel":"","context":"In "Anything Linux"","block_context":{"text":"Anything Linux","link":"http:\/\/bangla.sitestree.com\/?cat=1976"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":76576,"url":"http:\/\/bangla.sitestree.com\/?p=76576","url_meta":{"origin":78684,"position":1},"title":"How to Disable SELinux","author":"Sayed","date":"January 12, 2025","format":false,"excerpt":"Ref: https:\/\/www.ibm.com\/docs\/en\/tnpm\/1.4.5?topic=tasks-disable-selinux-linux-only Sample File:","rel":"","context":"In "Root"","block_context":{"text":"Root","link":"http:\/\/bangla.sitestree.com\/?cat=1"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/bangla.sitestree.com\/wp-content\/uploads\/2025\/01\/image-9.png?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":26256,"url":"http:\/\/bangla.sitestree.com\/?p=26256","url_meta":{"origin":78684,"position":2},"title":"Part-2: If you want to learn security, or if you already are a security professional\/engineer, can you answer the following questions on Security? Do you know (and can do) the answers to the following questions on Security? #Root","author":"Author-Check- Article-or-Video","date":"April 21, 2021","format":false,"excerpt":"What are the important concepts to know and implement for Infrastructure security? Consider only the software side. What are patching, hardening, enabling encryption, filtering connections in regards to network infrastructure? What is the relation with security? What will you do in regards to these? How is software patching different for\u2026","rel":"","context":"In "FromSitesTree.com"","block_context":{"text":"FromSitesTree.com","link":"http:\/\/bangla.sitestree.com\/?cat=1917"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":20401,"url":"http:\/\/bangla.sitestree.com\/?p=20401","url_meta":{"origin":78684,"position":3},"title":"Learn some Centos\/Redhat Linux: RHCE: MariaDB Administration on Redhat\/Fedora\/CentOS","author":"Author-Check- Article-or-Video","date":"February 20, 2021","format":false,"excerpt":"RHCE: MariaDB Administration on Redhat\/Fedora\/CentOS Check if mariaDB is installed or not 130 yum list installed | grep ^mariadb mariaDB originated from MySQL - after MySQL Got Bought by Oracle 133 yum list installed | grep ^mariadb I see - installed though not completely Output: mariadb-libs.x86_64 1:5.5.52-1.el7 @anaconda There are\u2026","rel":"","context":"In "FromSitesTree.com"","block_context":{"text":"FromSitesTree.com","link":"http:\/\/bangla.sitestree.com\/?cat=1917"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":20403,"url":"http:\/\/bangla.sitestree.com\/?p=20403","url_meta":{"origin":78684,"position":4},"title":"Learn some Centos\/Redhat Linux: RHCE: MariaDB Administration on Redhat\/Fedora\/CentOS","author":"Author-Check- Article-or-Video","date":"February 20, 2021","format":false,"excerpt":"The author is: the_authornRHCE: MariaDB Administration on Redhat\/Fedora\/CentOS Check if mariaDB is installed or not 130 yum list installed | grep ^mariadb mariaDB originated from MySQL - after MySQL Got Bought by Oracle 133 yum list installed | grep ^mariadb I see - installed though not completely Output: mariadb-libs.x86_64 1:5.5.52-1.el7\u2026","rel":"","context":"In "FromSitesTree.com"","block_context":{"text":"FromSitesTree.com","link":"http:\/\/bangla.sitestree.com\/?cat=1917"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":20405,"url":"http:\/\/bangla.sitestree.com\/?p=20405","url_meta":{"origin":78684,"position":5},"title":"Learn some Centos\/Redhat Linux: RHCE: MariaDB Administration on Redhat\/Fedora\/CentOS","author":"Author-Check- Article-or-Video","date":"February 20, 2021","format":false,"excerpt":"The author is: the_authornRHCE: MariaDB Administration on Redhat\/Fedora\/CentOS Check if mariaDB is installed or not 130 yum list installed | grep ^mariadb mariaDB originated from MySQL - after MySQL Got Bought by Oracle 133 yum list installed | grep ^mariadb I see - installed though not completely Output: mariadb-libs.x86_64 1:5.5.52-1.el7\u2026","rel":"","context":"In "FromSitesTree.com"","block_context":{"text":"FromSitesTree.com","link":"http:\/\/bangla.sitestree.com\/?cat=1917"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]}],"_links":{"self":[{"href":"http:\/\/bangla.sitestree.com\/index.php?rest_route=\/wp\/v2\/posts\/78684","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/bangla.sitestree.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/bangla.sitestree.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/bangla.sitestree.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/bangla.sitestree.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=78684"}],"version-history":[{"count":1,"href":"http:\/\/bangla.sitestree.com\/index.php?rest_route=\/wp\/v2\/posts\/78684\/revisions"}],"predecessor-version":[{"id":78685,"href":"http:\/\/bangla.sitestree.com\/index.php?rest_route=\/wp\/v2\/posts\/78684\/revisions\/78685"}],"wp:attachment":[{"href":"http:\/\/bangla.sitestree.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=78684"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/bangla.sitestree.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=78684"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/bangla.sitestree.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=78684"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}