CVE-2022-48658

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:
__flush_work.isra.0+0xbf/0x220 ? __queue_work+0x1dc/0x420
flush_all_cpus_locked+0xfb/0x120 __kmem_cache_shutdown+0x2b/0x320
kmem_cache_destroy+0x49/0x100 bioset_exit+0x143/0x190
blk_release_queue+0xb9/0x100 kobject_cleanup+0x37/0x130
nvme_fc_ctrl_free+0xc6/0x150 [nvme_fc] nvme_free_ctrl+0x1ac/0x2b0
[nvme_core] Fix this bug by creating a workqueue for the flush operation
with the WQ_MEM_RECLAIM bit set.