# CVE-2026-90390: md/bitmap: resume array on backlog_store() error path

> A local attacker with high privileges can cause a denial of service by triggering an error path that leaves the MD array suspended.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-90390, DEBIAN-CVE-2026-90390, GHSA-xj4x-xc4w-3c2g, UBUNTU-CVE-2026-90390

## What is CVE-2026-90390?

CVE-2026-90390 is a denial of service vulnerability in Linux, published on 17 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:

md/bitmap: resume array on backlog_store() error path

backlog_store() suspends the array before checking whether a write-mostly
device exists. If no such device exists, the error path only unlocks
reconfig_mutex and leaves the array suspended, blocking subsequent I/O.

Use mddev_unlock_and_resume() to release both states.

## Which versions are affected by CVE-2026-90390?


## How do I fix CVE-2026-90390?

Apply the vendor's patch.

## Is CVE-2026-90390 being exploited?

There is no known exploitation of CVE-2026-90390 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90390 and fix it if it is affected.

What it is: CVE-2026-90390 is a denial of service vulnerability in Linux, published on 17 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-2026-90390 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-2026-90390/ (Markdown: https://insights.sbomify.com/CVE-2026-90390/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90390
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90390
- OSV: https://osv.dev/vulnerability/CVE-2026-90390

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90390/
Summaries are generated and may contain mistakes; the official description above is the record.