# CVE-2026-80881: ocfs2: fix buffer head management in ocfs2_read_blocks()

> A flaw in the Linux kernel OCFS2 filesystem allows attackers to corrupt memory or cause denial of service by exploiting improper buffer head management.

- **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:** 4 Sep 2026
- **Updated:** 4 Sep 2026
- **Also known as:** BELL-CVE-2026-80881, DEBIAN-CVE-2026-80881, GHSA-5x8p-2x56-54gv, UBUNTU-CVE-2026-80881

## What is CVE-2026-80881?

CVE-2026-80881 is a memory corruption vulnerability in Linux, published on 4 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:

ocfs2: fix buffer head management in ocfs2_read_blocks()

In ocfs2_read_blocks(), caller should't assume that buffer head returned
by 'sb_getblk()' is exclusively owned and so 'put_bh()' always drops
b_count from 1 to 0.  If it is not so, buffer head remains on hold and
likely to be returned by the next call to 'sb_getblk()' unchanged - that
is, with BH_Uptodate bit set even if it has failed validation previously,
thus allowing to insert that buffer head into OCFS2 metadata cache and
submit it to upper layers.  To avoid such a scenario, BH_Uptodate should
be cleared immediately after 'validate()' callback has detected some data
inconsistency.

## Which versions are affected by CVE-2026-80881?


## How do I fix CVE-2026-80881?

Apply the vendor's patch.

## Is CVE-2026-80881 being exploited?

There is no known exploitation of CVE-2026-80881 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80881 and fix it if it is affected.

What it is: CVE-2026-80881 is a memory corruption vulnerability in Linux, published on 4 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-2026-80881 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-2026-80881/ (Markdown: https://insights.sbomify.com/CVE-2026-80881/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80881
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80881
- OSV: https://osv.dev/vulnerability/CVE-2026-80881

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80881/
Summaries are generated and may contain mistakes; the official description above is the record.