Use-After-Free Vulnerability in Linux Kernel HID for Steam Devices

CVE-2025-21923

Summary

This vulnerability in the Linux kernel involves a use-after-free condition within the HID Steam driver. When a hid-steam device is detached, the client_hdev responsible for managing hidraw access is expected to be cleaned up promptly. However, due to improper handling, the deferred work intended to reattach the input device may remain scheduled even after the client_hdev is cleaned up. This leads to potential instability, as the memory associated with the client_hdev could be reused inappropriately. A patch has been developed to correct the sequence of operations, ensuring that deferred work is effectively canceled before any cleanup occurs.

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