Critical TOCTOU Vulnerability in Linux Kernel vsock Module
Summary
CVE-2025-38461: In the Linux kernel, the following vulnerability has been resolved: vsock: Fix transport_* TOCTOU Transport assignment may race with module unload. Affects linux versions 5.10.103-1 – 6.9.9-1. No fix is published. How to fix ↓
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Background
The Linux kernel is the core component of many operating systems, providing essential services for hardware and software interaction. The vsock module facilitates communication between virtual machines and the host system. This module is crucial for applications that require efficient data exchange in virtualized environments. However, it is susceptible to a Time-of-Check to Time-of-Use (TOCTOU) vulnerability, which can lead to serious security issues if not addressed.
Vulnerability Detail
In the Linux kernel, a vulnerability has been identified in the vsock module related to transport assignment. This issue arises from a race condition that may occur when a transport is assigned while a module is being unloaded. This can lead to the new transport pointer becoming stale, resulting in potential crashes or exploitation. The vulnerability is characterized by a page fault error, which can compromise system stability and security.
How To Fix
No fixed version is published for this vulnerability.
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Workaround
As a temporary workaround, users can avoid using the vsock module until the system is updated with the patched version. Additionally, ensuring that no modules are unloaded while transport assignments are in progress can help mitigate the risk.
Conclusion
The TOCTOU vulnerability in the Linux kernel's vsock module poses significant risks to system stability and security. It is essential for users to update their systems promptly to mitigate these risks. Utilizing tools like Vulert can assist in monitoring and identifying vulnerabilities in open-source software.
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FAQ
The vulnerability is a TOCTOU issue in the vsock module of the Linux kernel, which can lead to system instability and potential exploitation.
You can use the Vulert playground at Vulert Scanner to check if your application is affected by this vulnerability without needing to sign up.
Exploitation of this vulnerability can lead to system crashes, unauthorized access, and compromise of sensitive data.
Yes, patches are available in the latest versions of the Linux package. It is crucial to update to these versions to ensure system security.
If immediate updates are not possible, refrain from using the vsock module and ensure that no modules are unloaded during transport assignments.
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