Linux Kernel Deadlock Vulnerability in BPF Event Mutex

CVE-2025-37884

Summary

A critical deadlock vulnerability has been identified in the Linux kernel's BPF subsystem, where the improper handling of event mutex can lead to system hangs. Specifically, the _free_event() function can simultaneously acquire the event_mutex while invoking synchronize_rcu_tasks_trace, creating a potential deadlock scenario. This vulnerability manifests when multiple CPU threads interact with tracing events, particularly during the execution of performance-related operations. A fix has been implemented to delegate trace_set_clr_event() to a workqueue, effectively avoiding lock dependencies and ensuring smoother operation of performance tracing functionalities.

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