Linux Kernel Vulnerability in batman-adv Metric Worker Implementation

CVE-2025-21823

Summary

A vulnerability in the Linux kernel's batman-adv module has been identified, affecting the calculation of ELP metrics for network interfaces. This issue arises due to an improper handling of neighbor metrics that may lead to invalid memory access if not managed correctly. When attempting to cancel a metric worker, potential deadlocks can occur during the interface removal process, as certain locks held by the worker conflict with the deactivation procedure. The resolution involves redesigning the handling of metric updates to better align with RCU protected contexts, ensuring stability and reliability within the network management protocol.

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