I just chmod 755 all directories, 644 to all files, and made sure directories such as /usr/bin/ all have +x bit, but I am not the most knowledgeable about the file system structure, how do I make sure everything is correct? (I accidentally chmod 644 / my entire system before this and that's how I messed it up initially)


The only sure method is to re-install. If you make a backup you could do a re-install without formatting /. That would overwrite all system files with their correct permissions.

I just chmod 755 all directories, 644 to all files

That is not correct for all the files on your system. It might make your system use able though.


  • /tmp/ needs 777 and sticky bit set.
  • Logfiles in /var/log/, some should be 640 (like syslog) to prevent "others" looking at your log files.
  • Oh, yeah I definitely looked into some of the stuff you mentioned, I just didn't know if there's anything that I missed - like I have my system up and files accessible but wanted to know if there's stuff like in your answer I need to make sure I change. Is there anything else you can think of? Thanks for the help – Preston Garno May 16 '17 at 10:25
  • Just make sure you can make a backup of your personal files and know you can restore it. If you have that set nothing to worry about when you format the machine. – Rinzwind May 16 '17 at 10:26
  • That actually might be a better use of my time – Preston Garno May 16 '17 at 10:28

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