# CVE-2022-48658: mm: slub: fix flush_cpu_slab()/__free_slab() invocations in task context.

> A kernel bug in the SLUB allocator can cause a workqueue dependency warning and potential system instability when specific memory reclaim workqueues are flushed.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 28 Apr 2024
- **Updated:** 5 Aug 2026
- **Also known as:** DEBIAN-CVE-2022-48658, GHSA-qr7h-9g6j-jwg3, UBUNTU-CVE-2022-48658

## What is CVE-2022-48658?

CVE-2022-48658 is a high-severity denial of service vulnerability in Linux kernel, published on 28 Apr 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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:
 __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.

## Which versions are affected by CVE-2022-48658?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2022-48658?

Apply the vendor's patch.

## Is CVE-2022-48658 being exploited?

There is no known exploitation of CVE-2022-48658 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-48658 and fix it if it is affected.

What it is: CVE-2022-48658 is a high-severity denial of service vulnerability in Linux kernel, published on 28 Apr 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2022-48658 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2022-48658/ (Markdown: https://insights.sbomify.com/CVE-2022-48658/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-48658
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-48658
- OSV: https://osv.dev/vulnerability/CVE-2022-48658

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-48658/
Summaries are generated and may contain mistakes; the official description above is the record.