Managing AppArmor profiles¶

Understanding AppArmor Risks in MySQL Development¶

While AppArmor profiles help secure your MySQL server, misconfiguring them can lead to unexpected behavior and potential security vulnerabilities. Here’s why careful review and testing are crucial when making changes:

Potential risks of misconfigured AppArmor profiles¶

Misconfiguration	Description
Overly restrictive profiles	These profiles might prevent MySQL from accessing necessary files or resources, hindering its functionality and causing errors. Imagine a profile accidentally blocking MySQL from writing to its log files, rendering them useless for troubleshooting.
Underly permissive profiles	Profiles with insufficient restrictions could allow unauthorized access to MySQL’s files or functionalities. This creates a security risk, as an attacker exploiting a vulnerability might leverage a permissive profile to gain more control over the server.
Incorrect profile assignment	Assigning the wrong profile to a process can lead to either of the issues mentioned above. For instance, accidentally assigning a profile meant for a different service to MySQL could have unintended consequences.

Importance of careful review and testing¶

By carefully reviewing and testing your AppArmor profile changes, you can minimize the risks associated with misconfigurations and ensure a secure and functional MySQL environment.

Review your changes thoroughly: Double-check your AppArmor profile modifications to ensure they grant MySQL the necessary permissions while maintaining security.
Test your changes in a safe environment: Before deploying changes to a production server, test them in a staging environment that mimics your production setup. This test allows you to identify and fix any issues caused by the AppArmor profile adjustments without impacting your live MySQL instance.

Install the utilities used to control AppArmor¶

Install the apparmor-utils package to work with profiles. Use these utilities to create, update, enforce, switch to complain mode, and disable profiles, as needed:

$ sudo apt install apparmor-utils

Expected output

Reading package lists... Done
Building dependency tree
...
The following additional packages will be installed:
    python3-apparmor python3-libapparmor
...

Add the mysqld profile¶

Add the mysqld profile with the following procedure:

Download the current version of the AppArmor:

$ wget https://raw.githubusercontent.com/percona/percona-server/release-8.4.3-3/build-ps/debian/percona-server-server.install

Expected output

...
Saving to 'apparamor-profile`
...

Move the file to /etc/apparmor.d/usr.sbin.mysqld

$ sudo mv apparmor-profile /etc/apparmor.d/usr.sbin.mysqld

Create an empty file for editing:

$ sudo touch /etc/apparmor.d/local/usr.sbin.mysqld

Load the profile:

$ sudo apparmor_parser -r -T -W /etc/apparmor.d/usr.sbin.mysqld

Restart Percona Server for MySQL:
```
$ sudo systemctl restart mysql
```

Verify the profile status:

$ sudo aa-status

Expected output

...
processes are in enforce mode
...
/usr/sbin/mysqld (100840)
...

Check the current status¶

As root or using sudo, you can check the AppArmor status:

$ sudo aa-status

Expected output

apparmor module is loaded.
34 profiles are loaded.
32 profiles in enforce mode.
...
    /usr/sbin/mysqld
...
2 profiles in complain mode.
...
3 profiles have profiles defined.
...
0 processes are in complain mode.
0 processes are unconfined but have a profile defined.

Switch a profile to complain mode¶

Switch a profile to complain mode when the program is in your path with this command:

$ sudo aa-complain <program>

If needed, specify the program’s path in the command:

$ sudo aa-complain /sbin/<program>

If the profile is not stored in /etc/apparmor.d/, use the following command:

$ sudo aa-complain /path/to/profiles/<program>

Switch a profile to enforce mode¶

Switch a profile to the enforce mode when the program is in your path with this command:

$ sudo aa-enforce <program>

If needed, specify the program’s path in the command:

$ sudo aa-enforce /sbin/<program>

If the profile is not stored in /etc/apparmor.d/, use the following command:

$ sudo aa-enforce /path/to/profile

Disable one profile¶

You can disable a profile but it is recommended to Switch a Profile to Complain mode.

Use either of the following methods to disable a profile:

$ sudo ln -s /etc/apparmor.d/usr.sbin.mysqld /etc/apparmor.d/disable/
$ sudo apparmor_parser -R /etc/apparmor.d/usr.sbin.mysqld

or

$ aa-disable /etc/apparmor.d/usr.sbin.mysqld

Reload all profiles¶

Run either of the following commands to reload all profiles:

$ sudo service apparmor reload

or

$ sudo systemctl reload apparmor.service

Reload one profile¶

To reload one profile, run the following: You may need to restart the program for some changes to take effect.

Useful links:¶

AppArmor
AppArmor Profiles
Disable AppArmor
Configure AppArmor
Troubleshoot AppArmor

Get expert help¶

If you need assistance, visit the community forum for comprehensive and free database knowledge, or contact our Percona Database Experts for professional support and services.

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Last update: 2024-12-18