- Red Hat Enterprise Linux 5
- Red Hat Enterprise Linux 6
- Need to restrict the normal users to run only limited set of commands assigned to him/her and all other commands for which normal user have permission to execute by-default, shall not be executed.
E.g: user XYZ can run only
Disclaimer : This is just a hack, not recommended for Actual Production Use
- The normal user has been given permission to execute some commands which are available in
/usr/local/bin/, So to remove those permissions and to restrict the user to run only particular set of commands, following steps shall be useful.
1. Create the restricted shell.
# cp /bin/bash /bin/rbash
2. Modify the target user for the shell as restricted shell
While creating user:
# useradd -s /bin/rbash localuser
For existing user:
# usermod -s /bin/rbash localuser
For more detailed information on this, please check the KBase Article 8349
Then the user
chrooted and can't access the links outside his home directory
3. Create a directory under
/home/localuser/, e.g. programs
# mkdir /home/localuser/programs
4. Now if you check, the user
localuser can access all commands which he/she has allowed to execute. These commands are taken from the environmental
PATH variable which is set in
/home/localuser/.bash_profile. Modify it as follows.
# cat /home/localuser/.bash_profile # .bash_profile # Get the aliases and functions if [ -f ~/.bashrc ]; then . ~/.bashrc fi # User specific environment and startup programs PATH=$HOME/programs export PATH
PATH variable is set to
~/programs directory, as
/usr/local/bin is binded to
/bin is binded to
/home/username/bin so replacing that.
5. Now after logging with the username
localuser, user cant run a simple command too. The output will be like this,
[localuser@example ~]$ ls -rbash: ls: command not found [localuser@example ~]$ less file1 -rbash: less: command not found [localuser@example ~]$ clear -rbash: clear: command not found [localuser@example ~]$ date -rbash: date: command not found [localuser@example ~]$ ping redhat.com -rbash: ping: command not found
6. Now create the softlinks of commands which are required for user
localuser to execute in the directory
# ln -s /bin/date /home/localuser/programs/ # ln -s /bin/ls /home/localuser/programs/ # ll /home/localuser/programs/ total 8 lrwxrwxrwx 1 root root 9 Oct 17 15:53 date -> /bin/date lrwxrwxrwx 1 root root 7 Oct 17 15:43 ls -> /bin/ls
Here examples of date and ls commands has been taken
7. Again login with user
localuser and try to execute the commands.
[localuser@example ~]$ date Mon Oct 17 15:55:45 IST 2011 [localuser@example ~]$ ls file1 file10 file2 file3 file4 file5 file6 file7 file8 file9 programs [localuser@example ~]$ clear -rbash: clear: command not found
8. One more step can be added to restrict the user for making any modifications in their
.bash_profile , as users can change it.
Run the following command to make the user
.bash_profile file as immutable so that root/localuser can't modify it until root removes immutable permission from it.
# chattr +i /home/localuser/.bash_profile
To remove immutable tag,
# chattr -i /home/localuser/.bash_profile
Make file .bash_profile as
immutable so that user
localuser can't change the environmental paths.
- Red Hat Enterprise Linux
- Learn more
This solution is part of Red Hat’s fast-track publication program, providing a huge library of solutions that Red Hat engineers have created while supporting our customers. To give you the knowledge you need the instant it becomes available, these articles may be presented in a raw and unedited form.