Critical Vulnerability in Linux Kernel: io_uring/net Abuse
Summary
DEBIAN-CVE-2025-23154: In the Linux kernel, the following vulnerability has been resolved: io_uring/net: fix io_req_post_cqe abuse by send bundle [ 114.987980][ T5313] WARNING: CPU: 6 PID: 5313 at io_uring/io_uring.c:872 io_req_post_cqe+0x12e/... Affects linux versions < 6.12.25-1. Fixed in 6.12.25-1. How to fix ↓
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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 is widely used across various platforms, including servers, desktops, and embedded systems. This vulnerability affects the io_uring subsystem, which provides an efficient interface for asynchronous I/O operations, allowing applications to perform I/O operations without blocking. The specific issue arises from improper handling of request completion events, leading to potential system instability or unexpected behavior.
Vulnerability Detail
In the Linux kernel, a vulnerability has been identified in the io_uring subsystem, specifically related to the function io_req_post_cqe. This function is intended for use with multishot requests, but it is being misused in the context of bundled sends, which do not require multiple completion queue entries (CQEs). This misuse can lead to warnings and potential crashes, as the system may attempt to post CQEs incorrectly. The vulnerability was introduced in earlier versions of the kernel and has been fixed in version 6.12.25-1.
How To Fix
Minimum fixed version
6.12.25-1
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. The best course of action is to apply the patch as soon as it is available.
Conclusion
The identified vulnerability in the Linux kernel's io_uring subsystem poses a risk of system instability due to improper handling of completion queue entries. Users are strongly encouraged to update to the patched version 6.12.25-1 to mitigate this risk. Monitoring tools like Vulert can help keep track of such vulnerabilities in the future.
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FAQ
The vulnerability involves improper handling of completion queue entries in the io_uring subsystem, which can lead to system warnings and instability.
The vulnerability affects all versions prior to 6.12.25-1.
You can check your kernel version using the command 'uname -r' in the terminal. If it is below 6.12.25-1, your system is vulnerable.
Yes, you can use tools like Vulert, which monitors open-source vulnerabilities in your software using a manifest file like package-lock.json.
While there are no specific workarounds, it is advisable to limit exposure to potential attacks until the kernel can be updated.
References
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