UAF bug in ax25_send_control() in Kernel

Kernel Updated 02 Oct 2025

Summary

24/04/2022

Disclosed on

N/A

Severity

No i

Fix available

Unrated

Severity

Not published

CVSS Score

GSD-2022-1002021: ax25: fix UAF bug in ax25_send_control(). Affects Kernel versions >= b20a5ab0f5fb175750c6bafd4cf12daccf00c738, < a4942c6fea879972a7fee50f7e92e2e10f3fc23e. No fix is published. How to fix ↓

Free scan

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.

Check my app free

No signup required · Results in about 60 seconds

Upload your dependency manifest or SBOM

Drag & drop your file here or Browse

Java Javascript PHP Python Go Rust Ruby Dart C/C++ Elixir CycloneDX SPDX

Upload a supported dependency manifest or SBOM. No installation or source-code access required.

See supported files and SBOM formats

SBOM sbom.json · bom.json · bom.xml · *.spdx.json · *.cdx.json · *.cdx.xml

Java pom.xml · gradle.lockfile · buildscript-gradle.lockfile

Javascript package-lock.json · yarn.lock · pnpm-lock.yaml

PHP composer.lock

Python poetry.lock · requirements.txt · Pipfile.lock

Go go.mod

Rust Cargo.lock

Ruby Gemfile.lock

Dart pubspec.lock

C/C++ conan.lock

Elixir mix.lock

Enter your work email to receive your report link.

Verify your email to view the full report and start 30 days of continuous monitoring. No credit card required.

Background

The Kernel is a crucial component of the Linux operating system that manages system resources and provides an interface for software to interact with the hardware. It is responsible for tasks such as memory management, process scheduling, and device drivers. The ax25 module in the Kernel is used for implementing the AX.25 protocol, which is a data link layer protocol for amateur radio communications.

The ax25_send_control() function in the ax25 module is responsible for sending control frames in the AX.25 protocol. However, a use-after-free (UAF) bug has been discovered in this function, which can lead to potential security vulnerabilities.

Vulnerability Detail

The UAF bug in ax25_send_control() allows an attacker to exploit a use-after-free vulnerability. This type of vulnerability occurs when a program uses a pointer to a memory object after it has been freed. By manipulating the freed memory, an attacker can potentially execute arbitrary code or cause a denial-of-service (DoS) condition.

In the case of this specific vulnerability, an attacker could send specially crafted control frames to a vulnerable system, triggering the UAF bug in ax25_send_control(). This could lead to the execution of arbitrary code with kernel privileges or a system crash.

The vulnerability was introduced in version v5.10.112 of the Linux Kernel by commit b20a5ab0f5fb175750c6bafd4cf12daccf00c738. It has been fixed in version v5.10.112 by commit a4942c6fea879972a7fee50f7e92e2e10f3fc23e.

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

There is no known workaround for this vulnerability. It is recommended to apply the fix mentioned above by updating the Linux Kernel to the latest version.

Conclusion

The UAF bug in ax25_send_control() in the Kernel is a critical vulnerability that can be exploited by attackers to execute arbitrary code or cause a system crash. It is recommended to update the Linux Kernel to the latest version to mitigate this vulnerability. For further support on vulnerability remediation, you can contact DevNack.com.

See every vulnerability recorded for Kernel →