Linux system misoperation execution: chmod-R 777 / later repair method
Accidental misoperation: chmod-R 777! It's over? Modified all file permissions of the Linux system, for reference only!
Linux system has no operation to execute: repair method after chmod-R 777:
1) do not exit the current login window after execution!
If you cannot log in to ssh, it should have something to do with the files passwd, group, shadow and ssh. Open another linux to view the permissions and modify them to the corresponding permissions on the wrong machine:
Cd / etc
Chmod 644 passwd group shadow
Chmod 400 gshadow
Cd ssh
Chmod 600 moduli ssh_host_dsa_key ssh_host_key ssh_host_rsa_key
Chmod 644 ssh_config ssh_host_dsa_key.pub ssh_host_key.pub ssh_host_rsa_key.pub
Chmod 640 sshd_config
Service sshd restart restarts the sshd service
Test reconnecting to ssh to see if the connection can be successful until the connection is successful
2)
Find a linux system (as clean as possible), export the permissions of the system, and then import it into this machine.
Execute on a good machine
Cd /
Getfacl-R / > linux.chmod.txt
Then upload it to the machine to be repaired by ftp or rz command
Execute:
Cd /
Setfacl-restore=linux.chmod.txt
Check directly: whether the permission is normal! Abnormal execution again, check again to see if it is normal!
If it is not executed in the / directory and the result does not take effect, you will probably need reboot! All recommended export and import operations under the root / directory
If it is not normal, you can do the following before trying reboot,reboot again:
Mkdir-p / root/sh
Cd / root/sh/
Vi sshtmp.sh
#-start-
Sleep 300
Cd / etc
Chmod 644 passwd group shadow
Chmod 400 gshadow
Cd ssh
Chmod 600 moduli ssh_host_dsa_key ssh_host_key ssh_host_rsa_key
Chmod 644 ssh_config ssh_host_dsa_key.pub ssh_host_key.pub ssh_host_rsa_key.pub
Chmod 640 sshd_config
Chmod upright s `which su`
Chmod 755`which passwd`
Chmod Ubuns `which passwd`
Service sshd restart
#-end-
Put it on and start it up
Echo'/ root/sh/sshtmp.sh &'> > / etc/rc.local
And then reboot.
If you can log in to the system normally after reboot, you can first kill the process of sshtmp.sh and remove the script in / etc/rc.local. Then check to see if the permissions are normal.
Reference material for this article: http://blog.sina.com.cn/s/blog_5937eedc0101h719.html
