# CVE-2021-47498: dm rq: don't queue request to blk-mq during DM suspend

> A race condition in the Linux kernel device mapper can cause a kernel panic during suspend operations, leading to system denial of service.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 22 May 2024
- **Updated:** 11 May 2026
- **Also known as:** DEBIAN-CVE-2021-47498, GHSA-78c9-2m2m-j8fh, ROOT-OS-DEBIAN-11-CVE-2021-47498, UBUNTU-CVE-2021-47498

## What is CVE-2021-47498?

CVE-2021-47498 is a medium-severity denial of service vulnerability in Linux kernel, published on 22 May 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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

dm rq: don't queue request to blk-mq during DM suspend

DM uses blk-mq's quiesce/unquiesce to stop/start device mapper queue.

But blk-mq's unquiesce may come from outside events, such as elevator
switch, updating nr_requests or others, and request may come during
suspend, so simply ask for blk-mq to requeue it.

Fixes one kernel panic issue when running updating nr_requests and
dm-mpath suspend/resume stress test.

## Which versions are affected by CVE-2021-47498?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2021-47498?

Apply the vendor's patch.

## Is CVE-2021-47498 being exploited?

There is no known exploitation of CVE-2021-47498 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-2021-47498 and fix it if it is affected.

What it is: CVE-2021-47498 is a medium-severity denial of service vulnerability in Linux kernel, published on 22 May 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-47498 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-2021-47498/ (Markdown: https://insights.sbomify.com/CVE-2021-47498/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-47498
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-47498
- OSV: https://osv.dev/vulnerability/CVE-2021-47498

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-47498/
Summaries are generated and may contain mistakes; the official description above is the record.