CVE-2024-26933 is a vulnerability identified in the Linux kernel's USB core subsystem, specifically related to the handling of the "disable" sysfs attribute for USB ports. The vulnerability arises from a deadlock condition caused by the show and store callback routines for the "disable" attribute in port.c acquiring the device lock for the port's parent hub device. When another process holds the hub lock to remove or reconfigure the hub, a circular wait occurs: the removal process waits for all outstanding sysfs attribute callbacks to complete, but those callbacks cannot complete until they acquire the hub lock, which is already held by the removal process. This results in a deadlock that halts the removal or reconfiguration operation. The fix involves invoking sysfs_break_active_protection(), which prevents the sysfs core from waiting for the attribute callback to return, allowing the removal to proceed. However, this introduces a risk that the hub structure could be deallocated unexpectedly. To mitigate this, the patch acquires a reference to the hub using hub_get() before breaking active protection, ensuring the hub remains valid during the operation. This vulnerability affects Linux kernel versions identified by the commit hash f061f43d7418cb62b8d073e221ec75d3f5b89e17 and likely other versions with similar USB core implementations. No known exploits are currently reported in the wild, and no CVSS score has been assigned yet.

For European organizations, this vulnerability could cause system instability or denial of service conditions on Linux-based systems that manage USB hubs and devices, particularly in environments where USB device hot-plugging or reconfiguration is frequent. The deadlock can halt device removal or configuration changes, potentially impacting critical infrastructure, industrial control systems, or enterprise servers relying on Linux. While it does not directly lead to privilege escalation or data leakage, the inability to properly manage USB devices could disrupt operations, especially in sectors like manufacturing, healthcare, or telecommunications where USB peripherals are integral. Additionally, the risk of system hangs or forced reboots to recover from deadlocks could increase operational costs and downtime. Since Linux is widely used across European governments, enterprises, and cloud providers, the vulnerability's impact is broad but primarily affects availability and system reliability rather than confidentiality or integrity.

European organizations should promptly apply the official Linux kernel patches that address this deadlock issue once available. Until patches are deployed, administrators should minimize USB hub reconfigurations or removals on critical systems, especially during peak operational hours. Monitoring system logs for USB-related errors or hangs can help detect attempts to trigger the deadlock. For environments with high USB device churn, consider isolating critical systems from frequent USB device changes or using USB device management policies to limit unauthorized device connections. Additionally, testing kernel updates in staging environments before production deployment is advisable to ensure stability. Organizations should also maintain up-to-date backups and have recovery procedures ready in case of system hangs caused by this vulnerability. Finally, coordinating with Linux distribution vendors for timely patch releases and security advisories is essential.