Use-After-Free Vulnerability in Linux Kernel's PTP OCP - CVE-2025-39859
Summary
CVE-2025-39859: In the Linux kernel, the following vulnerability has been resolved: ptp: ocp: fix use-after-free bugs causing by ptp_ocp_watchdog The ptp_ocp_detach() only shuts down the watchdog timer if it is pending. Affects linux versions 6.1.106-1 – 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. It supports various functionalities, including process management, memory management, and device control. The PTP (Precision Time Protocol) OCP (Open Control Protocol) is a feature within the kernel that facilitates precise time synchronization across networked devices. However, it is susceptible to vulnerabilities that can lead to critical security issues, such as use-after-free bugs.
Vulnerability Detail
The vulnerability identified as CVE-2025-39859 arises from a race condition in the PTP OCP implementation within the Linux kernel. Specifically, the issue occurs in the ptp_ocp_detach() function, which fails to properly deactivate a watchdog timer if it is already running. This oversight can lead to a scenario where the associated devlink is deallocated while the timer handler is still accessing it, resulting in use-after-free bugs. Such vulnerabilities can be exploited to execute arbitrary code, leading to system crashes or unauthorized access.
How To Fix
No fixed version is published for this vulnerability.
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Workaround
Currently, there are no specific workarounds mentioned for this vulnerability. The best course of action is to apply the available patch as soon as possible.
Conclusion
CVE-2025-39859 represents a significant vulnerability in the Linux kernel's PTP OCP implementation, leading to potential use-after-free issues. It is essential to apply the available patch promptly to safeguard your system against exploitation. Regular monitoring and updates are vital for maintaining system security.
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FAQ
CVE-2025-39859 is a vulnerability in the Linux kernel related to the PTP OCP that can lead to use-after-free bugs due to improper timer management.
Exploitation of this vulnerability can lead to arbitrary code execution, system crashes, or unauthorized access, posing significant security risks.
You can check if your application is affected by this vulnerability using the Vulert playground at Vulert Scanner, which analyzes your manifest file for vulnerabilities.
You can update the Linux package to the patched version by running the command: sudo apt-get update && sudo apt-get install linux=6.16.6-1.
While there are no specific workarounds available, it is crucial to prioritize updating your system to mitigate the risks associated with this vulnerability.
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