I really needed this presented just the way you did, this was a really great/clear explanation. The fact that you were able to make this make sense to me of all people, proves you deserve as many gold stars Red Hat can shower down on you.
Preparing for my comptia linux certification... Watched through beginning to end... now I will be re-creating each of these examples in my lab. This is awesome thank you
Just a tips for Windows user out there. Press the windows button and then type "Ease of access audio settings". In the "Turn on mono audio", toggle the button to change it to "On". You're very welcome ;)
Technically speaking the audio is RU-vid fault. When you submit it mono audio video (logical when you've recorded with only one mic), YT convert it to stereo but only feed one channel. So yeah it's weird I suggest that they develop mono audio support to stream just the original mono audio without converting it. And I suggest for the audio engine of every OS to automatically reproduce the sound of feeded channel to non feeded channel automatically (Like if you use 5.1 on a 7.1 or 2.1 on a 5.1 or whatever, no speakers should be left unused, it's annoying)
What a great presentation!!. It definitely changed my way of looking at SELinux and it will anyone struggling to understand those key concepts. I will share this video with my colleagues. Thanks for sharing.
@@parkasat * Media/Open Network Stream... (paste RU-vid video URL in the Network tab) When video starts to play, go to to * Audio/Stereo Mode (select Mono)
After spending couple of hours testing every example from this video, and fixing SEL issues on authorized_keys file, i feel like I get some new superpower. The feeling is PRICELESS!
An easier way to find the regular expression you need to change the context on your /foor/bar/ web content directory is to run `man semanage-fcontext` and jump down to the "EXAMPLES." Try `man -k semanage` to find some more related documentation. And to really get your hardcore nerd on, try this : `yum -y install selinux-policy-doc ; mandb ; man -k _selinux` and you'll find docs that explain the relevant contexts and booleans in pages like "httpd_selinux" and "sshd_selinux" and so on.
Excellent presentation skill! I don't use SELinux in the workplace but I'm confident to say I can handle basic situations by restorecon and semanage. Brovo, very nice presentation!
selinux prevented /bin/rightear from listening good information :) Thanks for the tricks managing basic stuff, will def write that down to my stay lazy notes
Third-party classes like I've taken for RHEL 5-7 keep selinux obfuscated and overcomplicate the instructions --- I suspect because they don't understand it themselves so they treat it like voodoo. Thank you for breaking it down like this!
Great presentation, but IMO, having to use "permissive" and policy modules looks like a failure in the concept of SELinux. Having to 'spray and pray' instead of fixing from first principles shows, to me, that the first principles are not very well thought-out.
Generally, SELinux works fine with software which is included with the distro. It's mostly when you start to use non-SELinux aware apps from third parties where it can get in your way. I hope that this helped you in those cases.
Just by seeing this I made sense of much of system admin stuff I've been exposed as a linux newcomer over the last year. To be honest is does seem rather easy to have this security layer. I'll try to install it in my system.
Does the SELinux labels do anything in a system that isn't using SELinux? So, if I physically remove the hard disk from a system protected by SELinux and mount it on a system that doesn't use SELinux, will the labels still protect the home folder of the user who chmod 777'd all his files or will I be able to read them because only DAC is active then? The second, right?
SELinux can't protect you when its not in use, if you break out the hdd you can read the data. If you disable selinux it will also not protect you anymore ...
well, if a service (Let's say a webserver) is being run as root and a hacker takes control of that service, without SELinux, your are done with SELinux, he may have "root-access", but not all the privileges because he still runs for example a shell as a child-process of the webserver
I've seen PHP based sites get compromised and PHP files over written. I've tried to simulate such an attack on Fedora. There are separate context types to allow and deny Apache and PHP-FPM from overwriting other code files.
@@kuhluhOG I know. I have already did a thesis for comparison between them. But blacklisting in apparmror is not as good and as developoed as in selinux
Sorry, I just now saw this. Armitage is just the name of the server I built the examples on. It's a character from the Neruomancer novel by William Gibson.
You want to keep your production environment as thin as possible. You should use those tools in a dev/test environment and replicate the problem there.
I find it funny that corporations are so worried about security but yet will force employees to run Windows as their desktop when that is about the worse thing you can run on your desktop.
I am trying to learn each element of the regular expression: "(/.*)?" Can someone help me fill in the blanks from the below: () == grouping regex together / == ??? . == equal to any one character * == equal to zero or more of the preceding character (in this case, would the previous character be "."?) ? == equal to zero or one of the preceding character (probably anything represented by (/.*) right?)
After doing a LOT of research... it would just seem that regex interprets the / as literally just a "\/" with no special meaning. So in this case, / would be interpreted as the typical subdirectory syntax.
Video Timestamp: @24:44 ~~~ NAME="CentOS Stream" VERSION="8" ~~~ It would seem that this file location no longer exists as shown here. /etc/selinux/targeted/m* ## dir does not exist From my research, you can find booleans.local under /var/lib/selinux/targeted/active/ It appears to contain the same information.
I am unclear on something. If you see from the logs that SELinux is blocking something, how do you know you should "fix" that by allowing the access? Maybe the "denied" or "prevented" messages should not be "fixed", because denying is exactly the right thing to do.
I talked about that. Just because something is blocked doesn't mean that it's a problem. You may be doing something wrong. If you know that you're doing something right, I talk about how to make changes via booleans or semanage fcontext. If you're not clear, feel free to ask questions, I'll help out however I can. Cheers!
if an attacker compromises the web server and able to exploit the OS and gain root privilege. Can SELinux stop the root user from doing malicious activity? This is a chicken and egg problem for me, since root should have access to modify the SELinux policy, but we also wanna stop attacker from modify the SELinux policy even if they get root access. Can this problem be solved at this level? Or we need some hardware to help us?
SE Linux: Built for NSA requirements. »Um it throws errors and we are lazy, so we turn it off. « Also: Oracle DB, built for NSA requirements. »We have to hire special administrators for that! It's important!« No double standards here, move on.
Great video for explaining SELinux but it changes nothing. In the real world, under a time pressure... you're going to just disable SELinux temporarily and move on with more important tasks. Like today when I had to change the timezone on the server, finding SELinux prevents the timedatectl command working. And your online help documentation is behind a paywall I don't have access to. Nothing covered in this video makes "the proper way" to fix that problem any more apparent.
You should probably re-watch it a few times. I talk about the appropriate methods for setting contexts, remediating problems, making the changes permanent, and what the implications for making those changes are. Holler if you need any additional help, happy to be of service.
Looks like he tries to sell me a SELinux. This is my very first meeting with SELinux. If booleans and labels around httpd are part of SELinux itself then its such a clumsy solution that i dont buy it. I think httpd process gets some context marker upon start with systemd unit config and future security checks are based on data context labels. This would make sense. But what are booleans that way then? Somehow hardcoded-ish things specially made for somehow recognized httpd process? I'll read about it later. This is just first thoughts mainly for myself.
