# CVE-2026-90389: md: scope memalloc_noio to allocation critical sections

> A race condition in the Linux kernel md driver allows local attackers to corrupt memory allocation flags, potentially leading to privilege escalation or system instability.

- **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:** AZL-102111, BELL-CVE-2026-90389, DEBIAN-CVE-2026-90389, GHSA-p657-p2pf-57vf, UBUNTU-CVE-2026-90389

## What is CVE-2026-90389?

CVE-2026-90389 is a 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: scope memalloc_noio to allocation critical sections

Storing a memalloc_noio_save() token in mddev->noio_flags lets one task
save the token and another task restore it. With concurrent suspend sysfs
writes, task A can enter PF_MEMALLOC_NOIO, return to userspace still in
that scope, and later task B can restore A's saved token.

Avoid tying the token lifetime to mddev. Keep mddev_suspend() and
mddev_resume() only responsible for array suspension, and enter
PF_MEMALLOC_NOIO only in the MD paths that allocate memory after the array
has been suspended. Restore the token before resuming the array.

A reproducer repeatedly writes suspend_lo and suspend_hi from concurrent
workers and checks each worker's /proc/self/stat flags before and after the
sysfs write.

## Which versions are affected by CVE-2026-90389?


## How do I fix CVE-2026-90389?

Apply the vendor's patch.

## Is CVE-2026-90389 being exploited?

There is no known exploitation of CVE-2026-90389 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90389 and fix it if it is affected.

What it is: CVE-2026-90389 is a 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-2026-90389 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-2026-90389/ (Markdown: https://insights.sbomify.com/CVE-2026-90389/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90389
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90389
- OSV: https://osv.dev/vulnerability/CVE-2026-90389

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90389/
Summaries are generated and may contain mistakes; the official description above is the record.