Critical Race Condition in Linux Kernel - linux Package Vulnerability
Summary
DEBIAN-CVE-2025-38242: In the Linux kernel, the following vulnerability has been resolved: mm: userfaultfd: fix race of userfaultfd_move and swap cache This commit fixes two kinds of races, they may have different results: Barry reported a BUG... Affects linux versions < 6.12.37-1. Fixed in 6.12.37-1. 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 managing system processes. This vulnerability affects Debian versions 13 and 14, specifically in the userfaultfd functionality, which is used for handling page faults in user space.
Vulnerability Detail
In the Linux kernel, a critical race condition has been identified in the userfaultfd implementation. This vulnerability arises from improper handling of swap cache entries during the userfaultfd_move operation. It can lead to corrupted RSS counters and potential system instability. The issue is triggered when multiple threads interact with the same memory pages, leading to unpredictable behavior and potential data corruption. The vulnerability was reported following a BUG_ON incident, indicating that the system could encounter serious errors under specific conditions.
How To Fix
Minimum fixed version
6.12.37-1
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 advisable to apply the patch as soon as it becomes available to mitigate the risks associated with this issue.
Conclusion
The identified vulnerability in the linux package of the Debian operating system poses significant risks due to a race condition in the kernel. Users are strongly encouraged to update to the patched version to ensure system stability and security. Regular monitoring and vulnerability management practices are essential to safeguard against such issues.
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FAQ
The vulnerability is a race condition in the Linux kernel's userfaultfd functionality, which can lead to corrupted memory state and system instability.
The vulnerability affects Debian versions 13 and 14 of the linux package.
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 without requiring any signup.
While there are no specific workarounds, it is crucial to monitor the situation and apply the patch as soon as possible to mitigate risks.
Yes, the vulnerability may lead to corrupted RSS counters and potentially unstable system behavior, although data corruption is not guaranteed.
References
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