CVE-2022-48658

/// Technical description

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

mm: slub: fix flush_cpu_slab()/__free_slab() invocations in task context.

Commit 5a836bf6b09f ("mm: slub: move flush_cpu_slab() invocations

__free_slab() invocations out of IRQ context") moved all flush_cpu_slab()

invocations to the global workqueue to avoid a problem related

with deactivate_slab()/__free_slab() being called from an IRQ context

on PREEMPT_RT kernels.

When the flush_all_cpu_locked() function is called from a task context

it may happen that a workqueue with WQ_MEM_RECLAIM bit set ends up

flushing the global workqueue, this will cause a dependency issue.

workqueue: WQ_MEM_RECLAIM nvme-delete-wq:nvme_delete_ctrl_work [nvme_core]

is flushing !WQ_MEM_RECLAIM events:flush_cpu_slab

WARNING: CPU: 37 PID: 410 at kernel/workqueue.c:2637

check_flush_dependency+0x10a/0x120

Workqueue: nvme-delete-wq nvme_delete_ctrl_work [nvme_core]

RIP: 0010:check_flush_dependency+0x10a/0x120[ 453.262125] Call Trace:

/// 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