Grsecurity Cores

Grsecurity is a patch for the Linux kernel that adds additional security mechanisms to the Linux kernel. The key functionality of Grsecurity is protection against memory spoofing attacks, as well as improving security policies for various components of the Linux system, such as network connections, file systems, IPC and others.

Grsecurity Features

The main purpose of Grsecurity is to protect against exploits designed to compromise system memory and intercept control over a computer or server. For these purposes, Grsecurity includes mechanisms that protect the kernel and user processes from attacks such as:

• Buffer overflow protection
• Protection against vulnerabilities in the kernel
• Cache and file system protection
• Separation (via RBAC) into access areas for physically separated processes

Grsecurity also provides tools for evaluating system security, such as security logging, system file inspection, and vulnerability testing.

However, the implementation of Grsecurity may require additional time and effort at each stage of development and deployment, which requires a certain level of expertise in the field of security.

The kernel has several important security features:

1. Protection against counterfeiting. Grsecurity patches the kernel to protect it from a variety of known hacking and compromise methods. This patch protects against fakes and exploits, and can disable or block access to vulnerable kernel functions.
2. Separation of access. Grsecurity has an RBAC (Role-Based Access Control) mechanism that will divide access into areas between physically separated processes. RBAC allows you to assign roles with an access rights engine that can be defined for each user or group.
3. Core protection. Grsecurity protects the kernel from corruption and unauthorized modification by controlling memory and system resources at a lower level of the kernel. This makes it impossible to execute code or change memory in the kernel without authorization.
4. Control of exported characters. Grsecurity controls which kernel functions can be called from kernel modules or from a user-defined spatial environment. Users can configure which symbols can be exported and used in kernel modules.
5. Protection of the network stack and TCP/IP stack. Grsecurity adds additional protection to the network stack and TCP/IP stack in the Linux kernel, which provides protection against DDoS attacks, as well as protection against other similar attacks.
6. Logging control. Grsecurity controls which users can view higher-level logs, access to which may contain sensitive information.

Grsecurity provides improved control over system security and provides more advanced security mechanisms compared to the standard Linux kernel.

Core Advantages

The advantages of Grsecurity include:

1. Significantly improved system security, as Grsecurity provides additional layers of protection that are not included in the standard Linux kernel.
2. Protection against most known types of attacks, including buffer overflow attacks, memory attacks, task scheduling attacks, and many others.
3. The ability to customize Grsecurity to the individual needs and wishes of the user, which increases the optimality of work.
4. High performance in comparison with other security systems, which allows you to use Grsecurity on production machines without slowing down their work.
5. Grsecurity support is provided as an optional package, which makes its use more flexible in contrast to other security systems that can be embedded in the Linux kernel.
6. Grsecurity provides a "backward compatibility" mode that allows you to run programs created for the standard Linux kernel on a system with a protected kernel.

Next, let's look at the disadvantages of the modified kernel.

Disadvantages of the core

Despite the many advantages, Grsecurity has some disadvantages:

1. Limited support - Grsecurity is not included in the standard repositories of Linux distributions, and is supported by a limited number of developers. This means that users may face difficulties in installation and support.
2. High level of complexity - Setting up Grsecurity can be a complex and time-consuming process. Some options severely limit the functionality of the Linux kernel, so users should be well aware of how these options will affect their systems.
3. Functionality Limitation - Some Linux functions may be blocked or restricted in Grsecurity to ensure security. Sometimes this can lead to performance degradation or compatibility problems with other programs.
4. Proprietary status - Grsecurity is released under a license that does not guarantee free access to the source code. This can be a problem for those who prefer to use only free software.
5. Some routers with the specified name may simply not be suitable. It is necessary to choose correctly for a specific model.

How do I install the kernel? This issue will be considered as follows.

Installation process

Installing Grsecurity is somewhat more complicated than installing a regular Linux kernel, and requires some knowledge and experience in building the kernel. Here are the general steps to install Grsecurity:

1. Download the source code of the Linux kernel and Grsecurity from the official website.
2. Unzip the archives into a separate directory, for example, /usr/src.
3. Configure the Linux kernel using make menuconfig by selecting the appropriate Grsecurity settings.
4. Compile and install the Linux kernel using the make command.
5. Configure the system to use the new Linux kernel in the /boot/grub/grub.cfg file.
6. Reboot the system and make sure that the new Linux kernel runs without errors.

Please note that the Grsecurity installation process may vary depending on your Linux distribution and Linux kernel version. Therefore, before installing it is better to read the official documentation of Grsecurity and your Linux distribution to avoid problems and errors.