Critical Vulnerability in Linux Kernel: Incorrect Autogroup Migration Detection
Summary
DEBIAN-CVE-2025-21771: In the Linux kernel, the following vulnerability has been resolved: sched_ext: Fix incorrect autogroup migration detection scx_move_task() is called from sched_move_task() and tells the BPF scheduler that cgroup migratio... Affects linux versions < 6.12.16-1. Fixed in 6.12.16-1. How to fix ↓
Check if this vulnerability affects your application
Upload a manifest or SBOM and we'll show whether you're affected, plus every other risky package in the same scan.
No signup required · Results in about 60 seconds
Background
The Linux kernel is the core component of the Linux operating system, responsible for managing system resources and facilitating communication between hardware and software. It supports a wide range of functionalities, including process management, memory management, and device control. This vulnerability affects the Linux kernel versions in Debian 13 and 14, specifically related to the scheduling of tasks within cgroups and autogroups, which are essential for resource management in multi-tasking environments.
Vulnerability Detail
In the Linux kernel, a vulnerability has been identified in the scheduling extension (sched_ext) that affects the detection of autogroup migrations. The function scx_move_task() is invoked during task migrations, but it fails to accurately distinguish between cgroup and autogroup migrations. This oversight can lead to incorrect handling of task migrations, resulting in warnings and potential instability in task scheduling. The root cause lies in the lack of explicit tagging for threads undergoing migration, which complicates the differentiation between migration types.
How To Fix
Minimum fixed version
6.12.16-1
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, no specific workaround has been provided for this vulnerability. Users are encouraged to apply the patch as soon as it becomes available to mitigate any risks associated with this issue.
Conclusion
The vulnerability in the Linux kernel regarding incorrect autogroup migration detection poses a significant risk to system stability and performance. Users are strongly advised to update to the patched version to mitigate these risks. Monitoring tools like Vulert can assist in identifying vulnerabilities in your software without requiring access to the code.
See every vulnerability recorded for linux →
FAQ
The vulnerability can lead to incorrect task migration handling, which may cause system instability and performance degradation.
You can use tools like Vulert to monitor and alert for open-source vulnerabilities in your software. Visit Vulert Scanner to check if your application is affected.
Yes, the patched version of the Linux kernel is 6.12.16-1 for both Debian 13 and 14.
While no specific workaround is available, it is advisable to monitor system performance and apply the patch as soon as possible.
Detailed information can be found in the official Debian CVE database at https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2025-21771.json.
References
Related vulnerabilities
Recent vulnerabilities recorded for linux.
