RCU Protection Vulnerability in Linux Kernel - CVE-2025-21766
Summary
CVE-2025-21766: In the Linux kernel, the following vulnerability has been resolved: ipv4: use RCU protection in ip_rt_update_pmtu() ip_rt_update_pmtu() must use RCU protection to make sure the net structure it reads does not disappear. Affects linux versions 5.10.103-1 – 6.9.9-1. No fix is published. How to fix ↓
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Background
The Linux kernel is the core component of many operating systems, responsible for managing hardware resources and providing essential services to software applications. It is known for its stability, performance, and security features. However, vulnerabilities can arise, such as CVE-2025-21766, which affects various Debian versions of the Linux package.
Vulnerability Detail
CVE-2025-21766 is a vulnerability in the Linux kernel where the function __ip_rt_update_pmtu() fails to use RCU (Read-Copy-Update) protection. This oversight can lead to scenarios where the network structure being accessed may disappear, potentially causing system instability or crashes. The vulnerability highlights the importance of proper memory management and synchronization in kernel development.
How To Fix
No fixed version is published for this vulnerability.
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Workaround
Currently, no specific workarounds are provided for this vulnerability. It is recommended to apply the patch as soon as it becomes available.
Conclusion
CVE-2025-21766 is a significant vulnerability in the Linux kernel that requires immediate attention. Users are advised to update their systems to the latest patched version to ensure security and stability. Utilizing tools like Vulert can help monitor for vulnerabilities effectively.
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FAQ
CVE-2025-21766 is a vulnerability in the Linux kernel related to improper use of RCU protection in the __ip_rt_update_pmtu() function.
This vulnerability can lead to system instability or crashes due to improper memory management in the kernel.
The vulnerability affects the Linux package in Debian versions 11, 12, and 13.
You can use Vulert, which monitors and alerts for open-source vulnerabilities in real-time. Visit Vulert Scanner to check if your application is affected without needing to sign up.
While there are no specific workarounds, it is crucial to plan for an update as soon as possible to mitigate the risk associated with this vulnerability.
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