AlmaLinux Kernel-rt Security Update: 4.18.0-553.83.1

Nov 10, 2025 by Admin 53 views

Hey everyone! A new security update is available for the AlmaLinux kernel-rt packages. This release, kernel-rt-4.18.0-553.83.1.rt7.424.el8_10, addresses several security concerns and is classified as having a moderate severity. If you're using AlmaLinux and rely on the real-time kernel, it's important to get this update installed to keep your system secure and stable. Let's dive into what this update brings and why it matters.

What is Kernel-rt?

Before we delve into the specifics of the update, let's quickly touch on what Kernel-rt is all about. The kernel-rt packages provide the Real Time Linux Kernel, a specialized version of the Linux kernel designed for systems that require extremely high determinism. This means that these systems need to perform tasks with very precise timing, making them ideal for applications like industrial control systems, audio processing, and robotics. In these scenarios, even slight delays can lead to significant issues, so a real-time kernel is crucial. For those of you working in such fields, you'll understand the importance of having a reliable and secure real-time operating system. Regular updates, especially security updates, are vital to maintaining that reliability and security.

Security Fixes in This Release

This particular release addresses three key security vulnerabilities, each identified by its CVE (Common Vulnerabilities and Exposures) number. These include:

CVE-2025-40300: kernel: x86/vmscape: Add conditional IBPB mitigation: This fix addresses a potential security issue related to speculative execution on x86 processors. More specifically, it adds a conditional Indirect Branch Prediction Barrier (IBPB) mitigation within the vmscape module. Speculative execution vulnerabilities, like Spectre and Meltdown, can potentially allow attackers to access sensitive information. Mitigations like IBPB help to prevent these types of attacks by controlling how the processor predicts and executes instructions. This particular mitigation is conditional, meaning it's applied only when necessary, optimizing performance while still providing security. For anyone concerned about hardware-level vulnerabilities, this is a crucial fix.
CVE-2023-53178: kernel: mm: fix zswap writeback race condition: This vulnerability involves a race condition in the zswap subsystem. Zswap is a Linux kernel feature that allows the system to compress and store less frequently used memory pages in a dedicated swap area in RAM. This can improve performance by reducing the need to swap pages to slower storage devices like hard drives or SSDs. However, a race condition can occur when multiple operations try to access the same memory location simultaneously, leading to unpredictable behavior or even system crashes. This fix ensures that the writeback process in zswap is handled correctly, preventing potential race conditions and improving system stability. If you're using zswap to optimize your system's memory usage, this fix is definitely one you'll want to have.
CVE-2022-50367: kernel: fs: fix UAF/GPF bug in nilfs_mdt_destroy: This security fix addresses a Use-After-Free (UAF) bug and a General Protection Fault (GPF) in the nilfs_mdt_destroy function within the kernel's filesystem code. A UAF vulnerability occurs when a program attempts to access memory that has already been freed, which can lead to crashes, data corruption, or even arbitrary code execution. A GPF, on the other hand, is a type of error that occurs when a program tries to access memory it doesn't have permission to access. This fix ensures that the nilfs_mdt_destroy function correctly manages memory, preventing these potentially severe issues. For those who rely on the NILFS filesystem, this fix is particularly important.

These security fixes are crucial for maintaining the integrity and security of your systems. Ignoring such vulnerabilities can expose your systems to potential attacks, data breaches, or system instability. Therefore, it’s highly recommended to apply this update as soon as possible.

Affected Packages

The following packages are affected by this security update and will be updated as part of the patch:

kernel-rt-4.18.0-553.83.1.rt7.424.el8_10.x86_64
kernel-rt-core-4.18.0-553.83.1.rt7.424.el8_10.x86_64
kernel-rt-debug-4.18.0-553.83.1.rt7.424.el8_10.x86_64
kernel-rt-debug-core-4.18.0-553.83.1.rt7.424.el8_10.x86_64
kernel-rt-debug-devel-4.18.0-553.83.1.rt7.424.el8_10.x86_64
kernel-rt-debug-modules-4.18.0-553.83.1.rt7.424.el8_10.x86_64
kernel-rt-debug-modules-extra-4.18.0-553.83.1.rt7.424.el8_10.x86_64
kernel-rt-devel-4.18.0-553.83.1.rt7.424.el8_10.x86_64
kernel-rt-modules-4.18.0-553.83.1.rt7.424.el8_10.x86_64
kernel-rt-modules-extra-4.18.0-553.83.1.rt7.424.el8_10.x86_64

Make sure to update all these packages to ensure your system is fully protected. The update process is usually straightforward, and using your distribution's package manager will take care of the dependencies and installation process.

How to Update Your System

Updating your AlmaLinux system is a straightforward process. You can use the dnf package manager, which is the default package management tool for AlmaLinux. Here’s how you can update your system:

Open a terminal: You'll need to open a terminal window to execute the update commands. This is your gateway to interacting with the system at a command-line level.
Run the update command: Execute the following command as the root user or with sudo privileges:
```
sudo dnf update
```
This command tells dnf to check for available updates and install them. It will download the necessary packages and perform the installation, ensuring your system is up to date.
Reboot your system: After the update is complete, it’s highly recommended to reboot your system. This ensures that the new kernel and updated packages are loaded and running correctly. Kernel updates, in particular, often require a reboot to take full effect.
```
sudo reboot
```
Rebooting is a crucial step in the update process, so don't skip it! It ensures that all the changes are properly applied and that your system is running the latest version of the kernel.

Following these steps will ensure that your system is running the latest version of the kernel-rt packages, including the critical security fixes. Keeping your system updated is one of the most effective ways to protect against vulnerabilities and ensure stability.

Why Timely Updates Matter

In the world of system administration and security, staying up-to-date is paramount. Security vulnerabilities are constantly being discovered, and attackers are always looking for ways to exploit them. By promptly applying security updates, you're essentially patching the holes that malicious actors could use to gain access to your system. Think of it like locking your doors and windows – you wouldn't leave them open, would you? The same principle applies to software updates.

Regular updates not only address security issues but also often include bug fixes, performance improvements, and new features. Ignoring updates can leave you vulnerable to known exploits and can also mean missing out on enhancements that could make your system run more efficiently. It’s a bit like driving a car without getting it serviced – eventually, something will break down.

For those of you managing systems in critical environments, such as industrial control or real-time processing, the importance of timely updates is even greater. Downtime can be costly, and security breaches can have severe consequences. By keeping your systems updated, you’re minimizing the risk of disruptions and ensuring the continued reliability of your operations.

So, guys, make it a habit to check for updates regularly and apply them as soon as possible. Your systems – and your peace of mind – will thank you for it.

Conclusion

This security update for the AlmaLinux kernel-rt packages is an important one, addressing several vulnerabilities that could potentially impact your system's security and stability. By updating to kernel-rt-4.18.0-553.83.1.rt7.424.el8_10, you're taking a proactive step to protect your systems and ensure they continue to run smoothly. Remember, staying informed about updates and applying them promptly is a crucial part of maintaining a secure and reliable computing environment.

So, go ahead and update your systems, folks! It's a small effort that can make a big difference in the long run. And as always, if you have any questions or run into any issues, don't hesitate to reach out to the AlmaLinux community for support. Stay secure, and keep those systems running smoothly!