Linux Kernel IDPF Driver Read Clock Lock Initialization Vulnerability

A vulnerability exists in the Linux kernel's IDPF driver related to the improper initialization of a spinlock used for managing access to a clock register. This issue arises because the lock is initialized after a worker thread has already been scheduled, creating a race condition. The scheduled worker can access the uninitialized lock, leading to a warning from the kernel's lock dependency checker about a 'non-static key' registration issue. This vulnerability affects the Linux kernel stable tree.

Impact

Exploitation of this vulnerability causes a kernel warning about a non-static key registration, indicating a potential issue with lock management that could be exploited in a real-time processing context.

Reproduction

To reproduce this vulnerability, load the IDPF driver in the Linux kernel stable tree. The vulnerability is triggered when the PTP (Precision Time Protocol) auxiliary worker is scheduled before the read_dev_clk_lock spinlock is properly initialized. This can be observed by monitoring the kernel logs for the 'trying to register non-static key' warning, which indicates that the PTP worker has attempted to access the clock lock before it was ready.

Remediation

The vulnerability has been addressed by moving the spinlock initialization earlier in the PTP initialization process, ensuring that the lock is ready before any worker threads are scheduled. Users should apply the latest patches available in the Linux kernel stable tree to mitigate this issue.