If for some reason some of the Linux system file permissions are broken, you can try and repair them with these steps. The prequisite you’ll need a root account to correct the permissions.
Find a working Linux server (preferably the same distribution and version) or boot from a live CD. Go to the folder you need the permissions from (for example cd /bin) and execute this command:
getfacl -R * > permissions.txt
Then go to the server with the wrong permissions, go to the same location, copy the permissions.txt file here and restore the permissions using:
setfacl –restore=permissions.txt
There you go! All permissions are now back as they were before.
https://www.linux.com/training-tutorials/how-easily-back-and-restore-linux-file-permissions/