CVE-2025-21983 is a high-severity vulnerability in the Linux kernel's memory management subsystem. It involves the kvfree_rcu() API using an inappropriate system workqueue (system_unbound_wq) for reclaiming memory, which can lead to kernel warnings and potential instability. The issue is addressed by switching to the WQ_MEM_RECLAIM workqueue, which is designed specifically for memory reclaim operations, thereby preventing workqueue framework rule violations.