Add user error useradd: cannot open /etc/passwd

When adding a user in a Linux environment, I found that it could not be added and encountered the following error

useradd: cannot open /etc/passwd

Solution

Use the lsattr command to view the hidden permissions of /etc/passwd

[~]# lsattr /etc/passwd

----i-------e- /etc/passwd

Permission i means that the setting file cannot be deleted, renamed, linked, and cannot be written or added.

Use the chattr command to remove the i permission bit from /etc/group:

[ ~]# chattr -i /etc/passwd

[ ~]# useradd -d /home/test -m test

useradd: cannot open /etc/shadow

Remove /etc/shadow permissions in the same way:

[ ~]# chattr -i /etc/shadow

[ ~]# useradd -d /home/test -m test

[ ~]#

Added successfully