Critical Vulnerability in Linux Kernel: vhost vringh Copy_to_iter Return Value Check
Summary
DEBIAN-CVE-2025-40056: In the Linux kernel, the following vulnerability has been resolved: vhost: vringh: Fix copy_to_iter return value check The return value of copy_to_iter can't be negative, check whether the copied length is equal to the r... Affects linux versions 6.1.106-1 – 6.9.9-1. No fix is published. 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
Habilume
Habit tracker with a companion that grows with you
Complete habits, earn Lume Points, and watch your Lume grow as you stay consistent.
Background
The Linux kernel is the core component of many operating systems, providing essential services for all other parts of the system. It manages hardware resources and allows software applications to communicate with the hardware. The kernel is crucial for system stability and security. This specific vulnerability affects the vhost subsystem, which is responsible for virtualized networking, and can lead to potential security risks if not addressed.
Vulnerability Detail
In the Linux kernel, a vulnerability has been identified in the vhost subsystem related to the vringh implementation. The issue arises from an improper check of the return value of the copy_to_iter function, which cannot be negative. Instead of checking for negative values, the code should verify whether the length of data copied matches the requested length. This oversight could lead to unexpected behavior or security vulnerabilities, potentially allowing attackers to exploit the system.
How To Fix
No fixed version is published for this vulnerability.
Tip — Not sure whether your app is affected? Vulert can check the versions your app actually runs. Scan free →
Workaround
Currently, no specific workaround has been provided for this vulnerability. Users are advised to apply the patch as soon as it becomes available to mitigate any potential risks.
Conclusion
The vulnerability identified as CVE-2025-40056 in the Linux kernel poses a significant risk due to improper return value checks in the vhost subsystem. It is crucial for users to update their systems to the latest patched version to mitigate potential security threats. Monitoring tools like Vulert can assist in identifying vulnerabilities in your software.
See every vulnerability recorded for linux →
FAQ
CVE-2025-40056 is a vulnerability in the Linux kernel related to the vhost subsystem, specifically concerning the return value check of the copy_to_iter function.
This vulnerability could lead to unexpected behavior in the vhost subsystem, potentially allowing attackers to exploit the system and compromise security.
If you are using Debian versions 12, 13, or 14, your system may be affected. It is advisable to check for updates and apply them promptly.
You can use Vulert, which monitors and alerts in real-time for open-source vulnerabilities using a manifest file like package-lock.json. You can check your application for vulnerabilities without requiring access to the code.
More information can be found in the official Debian security advisories or by visiting the Vulert playground at Vulert Scanner.
References
Related vulnerabilities
Recent vulnerabilities recorded for linux.
Habilume
Habit tracker with a companion that grows with you
Complete habits, earn Lume Points, and watch your Lume grow as you stay consistent.
