Understanding CVE-2024-26864: Addressing TCP Reference Count Handling in the Linux Kernel

Welcome to our detailed overview of CVE-2024-26864, a recently identified medium-severity vulnerability within the Linux kernel. This article aims to shed light on the technical nature of the issue, its potential impacts, and actions that Linux users can take to secure their systems. Our focus is to present this information in a clear, accessible manner, helping our readers at LinuxPatch.com stay informed and proactive about their cybersecurity.

What is CVE-2024-26864?

CVE-2024-26864 is a vulnerability that resides in the Linux kernel's TCP/IP networking stack, particularly within a function known as __inet_hash_connect(). Discovered by the automated testing system syzbot, the issue involves improper handling of reference counts during TCP connection setups, potentially leading to resource leaks and service disruptions due to underflow of reference counters.

This vulnerability was marked with a severity score of 5.9, categorizing it as a medium-level threat. The technical specifics indicate that the main concern revolves around the introduction of an unconnected socket into the ephemeral hash table when initial hash table (bhash2) allocation fails. Following this failure, if not remedied, the system is left vulnerable, with symptoms including possible kernel panics, unintended behavior, or even denial-of-service conditions.

Software Affected

The impacted component is the Linux kernel, specifically versions that include the flawed implementation of the __inet_hash_connect() function before the security patch was applied. The Linux kernel is the core of many Linux distributions, underpinning systems ranging from personal computers to heavy-duty servers. Its robustness and reliability are crucial for the operation of millions of devices and applications worldwide, making vulnerabilities such as CVE-2024-26864 particularly significant.

Impact of CVE-2024-26864

If exploited, the impact revolves around the stability and availability of network services. The technical specifics describe scenarios where, without adequate reference counting, an attacker could potentially trigger a refcnt underflow. This would lead to unallocated or incorrectly handled memory operations, culminating in system instability or crashes. Given the widespread use of Linux systems in networked environments, this issue could affect a significant number of users and devices.

Action and Mitigation

Addressing CVE-2024-26864 requires updating to a patched version of the Linux kernel. For LinuxPatch customers, we provide timely and reliable patches tailored to your specific installations. It’s crucial to update your systems as soon as possible to prevent potential exploits and maintain the integrity and security of your network environments.


While CVE-2024-26864 presents a clear threat to systems running vulnerable versions of the Linux kernel, the prompt application of available patches can mitigate these risks. We at LinuxPatch are committed to assisting our users in navigating these vulnerabilities with comprehensive patch management solutions.

For more information on this CVE and others, and to access our latest patches, visit our website at LinuxPatch.com. Keep your systems secure by staying ahead of vulnerabilities and ensuring your software is up-to-date.

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