# CVE-2026-89577: dm-io: report non-retryable errors separatedly

> A flaw in the Linux kernel dm-io subsystem could cause unnecessary RAID leg failures, leading to denial of service for local users.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 11 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-89577, DEBIAN-CVE-2026-89577, GHSA-fm7m-v5fw-6w27, UBUNTU-CVE-2026-89577

## What is CVE-2026-89577?

CVE-2026-89577 is a denial of service vulnerability in Linux, published on 11 Sep 2026. 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-io: report non-retryable errors separatedly

The error codes BLK_STS_NOTSUPP and BLK_STS_INVAL should not cause leg
failure on dm-raid1. This patch changes the interface to dm-io, so that
it reports two error bitmaps - error_bits and unsup_bits. The unsup_bit
bitmap tracks BLK_STS_NOTSUPP or BLK_STS_INVAL errors, the error_bits
bitmap tracks all the other errors.

dm-raid1 is changed so that it won't fail a leg if it receives an error
in the unsup_bits bitmap.

This patch (with 62dc37a819a5) fixes misbehavior if the user uses
unaligned bio vectors on dm-raid1.

## Which versions are affected by CVE-2026-89577?


## How do I fix CVE-2026-89577?

Apply the vendor's patch.

## Is CVE-2026-89577 being exploited?

There is no known exploitation of CVE-2026-89577 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89577 and fix it if it is affected.

What it is: CVE-2026-89577 is a denial of service vulnerability in Linux, published on 11 Sep 2026. 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-2026-89577 in the wild and no public exploit code.

Affected product: Linux. 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-2026-89577/ (Markdown: https://insights.sbomify.com/CVE-2026-89577/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89577
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89577
- OSV: https://osv.dev/vulnerability/CVE-2026-89577

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89577/
Summaries are generated and may contain mistakes; the official description above is the record.