CVE-2025-21983

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

mm/slab/kvfree_rcu: Switch to WQ_MEM_RECLAIM wq

Currently kvfree_rcu() APIs use a system workqueue which is

"system_unbound_wq" to driver RCU machinery to reclaim a memory.

Recently, it has been noted that the following kernel warning can

be observed:

<snip>

workqueue: WQ_MEM_RECLAIM nvme-wq:nvme_scan_work is flushing !WQ_MEM_RECLAIM events_unbound:kfree_rcu_work

WARNING: CPU: 21 PID: 330 at kernel/workqueue.c:3719 check_flush_dependency+0x112/0x120

Modules linked in: intel_uncore_frequency(E) intel_uncore_frequency_common(E) skx_edac(E) ...

CPU: 21 UID: 0 PID: 330 Comm: kworker/u144:6 Tainted: G E 6.13.2-0_g925d379822da #1

Hardware name: Wiwynn Twin Lakes MP/Twin Lakes Passive MP, BIOS YMM20 02/01/2023

Workqueue: nvme-wq nvme_scan_work

RIP: 0010:check_flush_dependency+0x112/0x120

Code: 05 9a 40 14 02 01 48 81 c6 c0 00 00 00 48 8b 50 18 48 81 c7 c0 00 00 00 48 89 f9 48 ...

RSP: 0018:

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References