Critical Vulnerability in Linux Kernel: Shadow Stack Activation Issue
Summary
DEBIAN-CVE-2025-21632: In the Linux kernel, the following vulnerability has been resolved: x86/fpu: Ensure shadow stack is active before "getting" registers The x86 shadow stack support has its own set of registers. Affects linux versions < 6.12.10-1. Fixed in 6.12.10-1. 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 many operating systems, responsible for managing hardware resources and providing essential services to applications. It is known for its stability, performance, and security features. However, vulnerabilities can arise, impacting its functionality and security. This specific vulnerability pertains to the x86 architecture's shadow stack support, which is crucial for maintaining secure execution environments.
Vulnerability Detail
In the Linux kernel, a vulnerability has been identified related to the x86 shadow stack support. The issue arises when the ptrace interface does not properly verify if the shadow stack is active before accessing registers. This oversight can lead to warnings and potential instability in the kernel, as the system may attempt to access uninitialized or invalid memory locations. The vulnerability was introduced due to a lack of checks in the regset code, which can be exploited if the shadow stack is disabled, leading to unexpected behavior and system warnings.
How To Fix
Minimum fixed version
6.12.10-1
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, ensuring that the kernel is updated to the latest version is the best practice to avoid potential issues.
Conclusion
The vulnerability in the Linux kernel regarding shadow stack activation is a critical issue that requires immediate attention. Users are encouraged to update their systems to the latest patched version to mitigate potential risks. Regular monitoring and updates are essential for maintaining system security.
See every vulnerability recorded for linux →
FAQ
The vulnerability can lead to system warnings and potential instability if the shadow stack is accessed while it is disabled.
You can use tools like Vulert to monitor and alert for open-source vulnerabilities in your software. Visit Vulert Scanner to check your application without any signup.
While there are no specific workarounds, it is advisable to monitor your system for unusual behavior and plan to update as soon as possible.
Yes, this vulnerability specifically affects the x86 architecture's implementation of shadow stack support.
Detailed information can be found in the Debian CVE database or by reviewing the changelog associated with the Linux kernel updates.
References
Related vulnerabilities
Recent vulnerabilities recorded for linux.
