Software & AppsOperating SystemLinux

How To Fix “sudo: /usr/bin/sudo must be owned by uid 0 and have the setuid bit set” Error in Ubuntu

Ubuntu 13

In this article, we will discuss a common error that Ubuntu users may encounter: “sudo: /usr/bin/sudo must be owned by uid 0 and have the setuid bit set”. This error typically occurs when the ownership or permissions of the /usr/bin/sudo file are incorrectly modified. We will provide a detailed guide on how to resolve this issue.

Quick Answer

To fix the "sudo: /usr/bin/sudo must be owned by uid 0 and have the setuid bit set" error in Ubuntu, you need to gain root access, correct the ownership and permissions of the /usr/bin/sudo file, and fix any additional issues with the /usr/lib/sudo/sudoers.so file or other relevant files and directories. Afterwards, log out and log back in as the current user to ensure the changes take effect.

Understanding the Error

Before we delve into the solution, it’s important to understand what the error message means. In Unix-like operating systems, such as Ubuntu, each file is associated with a user ID (uid) and a group ID (gid). The /usr/bin/sudo file should be owned by the root user (uid 0) and have the setuid bit set. This allows users to execute the sudo command with elevated privileges.

If the ownership or permissions of the /usr/bin/sudo file are changed, you may encounter the error message in question. This is often the result of accidentally running a command like sudo chown [username] -hR /, which changes the ownership of all files in the root directory.

Fixing the Error

Step 1: Gain Root Access

To fix the error, you need root access. If you don’t have a root user or don’t know the password, you can boot into recovery mode. Restart your system and press the Esc key to enter the grub menu. Select “Advanced options for Ubuntu” and then choose the recovery mode. From there, select the root option to access the root shell.

Step 2: Correct the Ownership and Permissions

Once you have root access, you can correct the ownership and permissions of the /usr/bin/sudo file by executing the following command:

chown root:root /usr/bin/sudo && chmod 4755 /usr/bin/sudo

In this command, chown root:root /usr/bin/sudo changes the ownership of the /usr/bin/sudo file to the root user and group. The && operator combines this with the chmod 4755 /usr/bin/sudo command, which sets the permissions of the file to 4755. This permission setting ensures that the file has the setuid bit set and is executable by all users.

Step 3: Fix Additional Issues

If you encounter additional issues with the /usr/lib/sudo/sudoers.so file, you can fix it by running the following command:

chown root:root /usr/lib/sudo/sudoers.so && chmod 4755 /usr/lib/sudo/sudoers.so

This command works similarly to the previous one, changing the ownership and permissions of the /usr/lib/sudo/sudoers.so file.

Step 4: Check Other Files and Directories

If necessary, you may also need to fix the ownership and permissions of other files and directories. For example, you can use the following command to fix the ownership of the /etc/sudoers file:

chown root:root /etc/sudoers

Step 5: Test the Changes

After making these changes, log out of the root user and log back in as the current user. The sudo command should now work properly.

Conclusion

In this article, we discussed how to fix the “sudo: /usr/bin/sudo must be owned by uid 0 and have the setuid bit set” error in Ubuntu. It’s crucial to be cautious when modifying system files and always double-check the commands you execute to avoid unintended consequences. In some cases, a reinstall of the operating system might be necessary to fully resolve the issue. Always remember, understanding the problem is the first step towards a successful resolution.

What is the purpose of the `sudo` command in Ubuntu?

The sudo command allows users to execute commands with elevated privileges. It is commonly used to perform administrative tasks that require root access.

How does the “sudo: /usr/bin/sudo must be owned by uid 0 and have the setuid bit set” error occur?

This error occurs when the ownership or permissions of the /usr/bin/sudo file are incorrectly modified, typically as a result of running a command that changes the ownership of all files in the root directory.

How can I fix the “sudo: /usr/bin/sudo must be owned by uid 0 and have the setuid bit set” error?

To fix the error, you need root access. You can gain root access by booting into recovery mode. Once in the root shell, you can correct the ownership and permissions of the /usr/bin/sudo file using the chown and chmod commands.

Are there any additional files or directories that I need to fix?

In addition to the /usr/bin/sudo file, you may need to fix the ownership and permissions of the /usr/lib/sudo/sudoers.so file and other relevant files or directories. The commands provided in the article can be used as a starting point.

What should I do if I encounter other issues or the error persists?

If you encounter additional issues or the error persists, it is recommended to seek further assistance or consider reinstalling the operating system as a last resort. It’s important to exercise caution when modifying system files and always double-check the commands you execute to avoid unintended consequences.

Leave a Comment

Your email address will not be published. Required fields are marked *