# CVE-2025-71161: dm-verity: disable recursive forward error correction

> A flaw in Linux kernel dm-verity allows attackers to cause denial of service via recursive forward error correction loops.

- **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:** 23 Jan 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-75129, AZL-78437, BELL-CVE-2025-71161, DEBIAN-CVE-2025-71161, GHSA-m3cp-9jq6-3gg3, ROOT-OS-DEBIAN-11-CVE-2025-71161, ROOT-OS-DEBIAN-12-CVE-2025-71161, ROOT-OS-DEBIAN-13-CVE-2025-71161, ROOT-OS-UBUNTU-2204-CVE-2025-71161, ROOT-OS-UBUNTU-2404-CVE-2025-71161, UBUNTU-CVE-2025-71161

## What is CVE-2025-71161?

CVE-2025-71161 is a high-severity denial of service vulnerability in Linux kernel, published on 23 Jan 2026. 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:

dm-verity: disable recursive forward error correction

There are two problems with the recursive correction:

1. It may cause denial-of-service. In fec_read_bufs, there is a loop that
has 253 iterations. For each iteration, we may call verity_hash_for_block
recursively. There is a limit of 4 nested recursions - that means that
there may be at most 253^4 (4 billion) iterations. Red Hat QE team
actually created an image that pushes dm-verity to this limit - and this
image just makes the udev-worker process get stuck in the 'D' state.

2. It doesn't work. In fec_read_bufs we store data into the variable
"fio->bufs", but fio bufs is shared between recursive invocations, if
"verity_hash_for_block" invoked correction recursively, it would
overwrite partially filled fio->bufs.

Weakness: CWE-193 (Off-by-one Error), CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2025-71161?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-71161?

Apply the vendor's patch.

## Is CVE-2025-71161 being exploited?

There is no known exploitation of CVE-2025-71161 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-2025-71161 and fix it if it is affected.

What it is: CVE-2025-71161 is a high-severity denial of service vulnerability in Linux kernel, published on 23 Jan 2026. 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-2025-71161 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-2025-71161/ (Markdown: https://insights.sbomify.com/CVE-2025-71161/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-71161
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-71161
- OSV: https://osv.dev/vulnerability/CVE-2025-71161

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-71161/
Summaries are generated and may contain mistakes; the official description above is the record.