# CVE-2026-45955: md/md-llbitmap: fix percpu_ref not resurrected on suspend timeout

> A Linux kernel bug in the md/llbitmap module causes a permanent denial of service by leaving a reference counter in a killed state after a timeout.

- **Severity:** High 7.1 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/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:** 27 May 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-45955, DEBIAN-CVE-2026-45955, GHSA-7293-q55v-843q, UBUNTU-CVE-2026-45955

## What is CVE-2026-45955?

CVE-2026-45955 is a high-severity denial of service vulnerability in Linux kernel, published on 27 May 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/md-llbitmap: fix percpu_ref not resurrected on suspend timeout

When llbitmap_suspend_timeout() times out waiting for percpu_ref to
become zero, it returns -ETIMEDOUT without resurrecting the percpu_ref.
The caller (md_llbitmap_daemon_fn) then continues to the next page
without calling llbitmap_resume(), leaving the percpu_ref in a killed
state permanently.

Fix this by resurrecting the percpu_ref before returning the error,
ensuring the page control structure remains usable for subsequent
operations.

Weakness: CWE-404 (Improper Resource Shutdown or Release)

## Which versions are affected by CVE-2026-45955?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-45955?

Apply the vendor's patch.

## Is CVE-2026-45955 being exploited?

There is no known exploitation of CVE-2026-45955 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-2026-45955 and fix it if it is affected.

What it is: CVE-2026-45955 is a high-severity denial of service vulnerability in Linux kernel, published on 27 May 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-2026-45955 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-2026-45955/ (Markdown: https://insights.sbomify.com/CVE-2026-45955/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-45955
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-45955
- OSV: https://osv.dev/vulnerability/CVE-2026-45955

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-45955/
Summaries are generated and may contain mistakes; the official description above is the record.