Improper Handling of Negative Read/Write Replies in Linux Kernel - CVE-2025-37879
Summary
CVE-2025-37879: In the Linux kernel, the following vulnerability has been resolved: 9p/net: fix improper handling of bogus negative read/write replies In p9_client_write() and p9_client_read_once(), if the server incorrectly replies wit... Affects linux versions 5.10.103-1 – 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
Background
The Linux kernel is a core component of many operating systems, providing essential services for hardware management, process scheduling, and system security. It is widely used in various distributions, including Debian. This vulnerability affects the 9p network file system, which allows for file sharing over a network. The issue arises from improper handling of negative read/write replies, which can lead to unexpected behavior.
Vulnerability Detail
CVE-2025-37879 is a vulnerability in the Linux kernel's 9p network file system. It occurs when the server incorrectly replies with a success status but provides a negative count for read/write operations. This can lead to a situation where the kernel misinterprets the negative count as valid, potentially causing a null pointer dereference or other unintended consequences. The root cause is the use of signed variables for counts, which can lead to logical errors when negative values are involved.
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
As a temporary workaround, you can avoid using the 9p network file system until the patch is applied. This can be done by disabling the 9p file system in your system configuration or by using alternative file sharing methods.
Conclusion
CVE-2025-37879 is a significant vulnerability in the Linux kernel affecting the 9p network file system. It is crucial for users to apply the necessary updates to mitigate potential risks associated with this issue. Utilizing tools like Vulert can help in monitoring vulnerabilities effectively.
See every vulnerability recorded for linux →
FAQ
CVE-2025-37879 is a vulnerability in the Linux kernel that affects the 9p network file system, allowing improper handling of negative read/write replies.
This vulnerability can lead to unexpected behavior, including potential null pointer dereferences, which may cause system instability or crashes.
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 needing to sign up.
If you cannot update your system, consider disabling the 9p network file system as a temporary workaround until a patch is applied.
More information can be found in the official CVE database or by checking the Linux kernel mailing lists for updates on the issue.
Related vulnerabilities
Recent vulnerabilities recorded for linux.
