Critical Vulnerability in Linux Kernel: NAPI Completion Issue
Summary
DEBIAN-CVE-2025-38270: In the Linux kernel, the following vulnerability has been resolved: net: drv: netdevsim: don't napi_complete() from netpoll netdevsim supports netpoll. Affects linux versions < 6.12.35-1. Fixed in 6.12.35-1. How to fix ↓
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Background
The Linux kernel is the core component of the Linux operating system, responsible for managing hardware resources and providing essential services to applications. It supports a wide range of functionalities, including process management, memory management, and device control. The kernel is crucial for system stability and performance, making it a prime target for vulnerabilities that can affect system security and reliability.
Vulnerability Detail
In the Linux kernel, a vulnerability has been identified in the netdevsim driver related to the netpoll feature. The issue arises when napi_complete() is called from netpoll, which may not be scheduled correctly, leading to potential system warnings and instability. This vulnerability was reported by Breno, who encountered a warning during operation, indicating that the SCHED bit was prematurely stolen by netpoll. The specific warning message is: 'WARNING: CPU: 14 PID: 104 at net/core/dev.c:6592 napi_complete_done()'. This could lead to unpredictable behavior in network operations, affecting overall system performance.
How To Fix
Minimum fixed version
6.12.35-1
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 mentioned for this vulnerability. However, users are advised to monitor their systems for any unusual behavior and apply the patch as soon as it is available.
Conclusion
The identified vulnerability in the Linux kernel related to the netdevsim driver poses significant risks to system stability and performance. Users are encouraged to update their systems to the patched version to mitigate these risks. Regular monitoring and updates are essential for maintaining a secure operating environment.
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FAQ
The vulnerability involves an improper call to napi_complete() from netpoll in the netdevsim driver, which can lead to system warnings and instability.
You can use Vulert to monitor and alert for open-source vulnerabilities in your software. Visit Vulert Scanner to check if your application is affected by this vulnerability without requiring any signup.
Failure to address this vulnerability may result in system instability, unpredictable network behavior, and potential security risks.
Yes, a patch is available in the form of an updated Linux package version 6.12.35-1.
It is recommended to regularly check for updates and apply them promptly to ensure your system is secure and stable.
References
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