I have created a jail with Jailkit and jailed a user.

However, after looking on the Jailkit description, I still cannot find a command to unjail the user.

How do I do that?

1 Answer 1

jk_jailuser - a utility to put an existing user in a jail

This seems to be true, it doesn't give you any option to remove a user from the jail.

Let us see what happens when you jail a user. Example:

To jail user jane, you use the command jk_jailuser -m -j /home/jail jane. The entry for user jane in /etc/passwd will be changed to this:


To unjail user jane you need to change the entry in /etc/passwd

I can't know how your original entry looked like, so here an example for the entry of my own account in /etc/passwd:


Here some additional information about the syntax for entries in /etc/passwd

____ _ ____ ____ _______ __________ _________
 1   2  3    4      5        6         7

1:  Username: It is used when user logs in. It should be between
    1 and 32 characters in length.
2:  Password: An x character indicates that encrypted password
    is stored in /etc/shadow file.
3:  User ID (UID): Each user must be assigned a user ID (UID).
    UID 0 (zero) is reserved for root and UIDs 1-99 are reserved
    for other predefined accounts. Further UID 100-999 are reserved by
    system for administrative and system accounts/groups.
4:  Group ID (GID): The primary group ID (stored in /etc/group file)
5:  User ID Info: The comment field. It allow you to add extra information
    about the users such as user’s full name, phone number etc. This field
    use by finger command.
6:  Home directory: The absolute path to the directory the user will be in
    when they log in.If this directory does not exists then users directory
    becomes /.
7:  Command/shell: The absolute path of a command or shell (/bin/bash).
    Typically, this is a shell.Please note that it does not have to be
    a shell.

After editing the entry in /etc/passwd correctly, your user should be free...

  • Yes and NO. Yes, because if you remove the user-directory from jail and remove the passwd-entry in /etc/passwd of the jail the user can't login anymore... But NO, because if you try to add a new user with the same name, you got some notices from jailkit, that this user still exist. (see: superuser.com/questions/1679028/remove-a-user-from-jailkit) It seems to be there are also other places where jailkit save information about user-accounts.
    – suther
    Sep 30, 2021 at 8:09

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