Critical Deadlock Vulnerability in Linux Kernel Package: linux
Summary
DEBIAN-CVE-2025-21809: In the Linux kernel, the following vulnerability has been resolved: rxrpc, afs: Fix peer hash locking vs RCU callback In its address list, afs now retains pointers to and refs on one or more rxrpc_peer objects. Affects linux versions < 6.12.13-1. Fixed in 6.12.13-1. How to fix ↓
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Background
The 'linux' package is a core component of the Debian operating system, providing the essential kernel that manages system resources and hardware interactions. It is responsible for enabling the execution of applications and ensuring system stability. This package is crucial for the overall functionality of the operating system, and vulnerabilities within it can lead to severe system issues, including crashes and security breaches.
Vulnerability Detail
In the Linux kernel, a vulnerability has been identified related to the handling of rxrpc_peer objects within the afs address list. The issue arises during the cleanup process, where an ordinary spinlock is used instead of a BH-disabling lock. This can lead to a deadlock scenario if the RCU cleanup occurs while the hash spinlock is held, resulting in inconsistent lock states and potential system hangs. The vulnerability is documented under DEBIAN-CVE-2025-21809 and affects versions prior to 6.12.13-1.
How To Fix
Minimum fixed version
6.12.13-1
This is the first release that contains the fix.
sudo apt-get install --only-upgrade linuxTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
Currently, there are no specific workarounds provided for this vulnerability. It is advised to apply the patch as soon as it is available to mitigate the risk.
Conclusion
The identified vulnerability in the Linux kernel package poses a significant risk to system stability due to potential deadlock scenarios. Users are encouraged to update to the latest patched version to mitigate this risk. Regular monitoring and updates are essential for maintaining system security.
See every vulnerability recorded for linux →
FAQ
The vulnerability is a deadlock issue in the Linux kernel related to the handling of spinlocks during the cleanup of rxrpc_peer objects.
You can check if your application is affected by using the Vulert playground at Vulert Scanner, which allows you to monitor vulnerabilities without requiring installation.
If exploited, this vulnerability can lead to system hangs or crashes, affecting the stability and reliability of the operating system.
While the primary risk is system instability, there is a potential for data loss if the system crashes unexpectedly.
It is recommended to regularly check for updates and apply them promptly to ensure your system is protected against known vulnerabilities.
References
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