# CVE-2023-54140: nilfs2: fix WARNING in mark_buffer_dirty due to discarded buffer reuse

> A local attacker with a corrupted disk image can trigger a kernel warning and panic in the nilfs2 filesystem, causing a denial of service.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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:** 24 Dec 2025
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2023-54140, DEBIAN-CVE-2023-54140, GHSA-8vr5-q73g-2w33, UBUNTU-CVE-2023-54140

## What is CVE-2023-54140?

CVE-2023-54140 is a high-severity vulnerability in Linux, published on 24 Dec 2025. 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:

nilfs2: fix WARNING in mark_buffer_dirty due to discarded buffer reuse

A syzbot stress test using a corrupted disk image reported that
mark_buffer_dirty() called from __nilfs_mark_inode_dirty() or
nilfs_palloc_commit_alloc_entry() may output a kernel warning, and can
panic if the kernel is booted with panic_on_warn.

This is because nilfs2 keeps buffer pointers in local structures for some
metadata and reuses them, but such buffers may be forcibly discarded by
nilfs_clear_dirty_page() in some critical situations.

This issue is reported to appear after commit 28a65b49eb53 ("nilfs2: do
not write dirty data after degenerating to read-only"), but the issue has
potentially existed before.

Fix this issue by checking the uptodate flag when attempting to reuse an
internally held buffer, and reloading the metadata instead of reusing the
buffer if the flag was lost.

## Which versions are affected by CVE-2023-54140?


## How do I fix CVE-2023-54140?

Apply the vendor's patch.

## Is CVE-2023-54140 being exploited?

There is no known exploitation of CVE-2023-54140 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-54140 and fix it if it is affected.

What it is: CVE-2023-54140 is a high-severity vulnerability in Linux, published on 24 Dec 2025. 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-2023-54140 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-2023-54140/ (Markdown: https://insights.sbomify.com/CVE-2023-54140/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-54140
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-54140
- OSV: https://osv.dev/vulnerability/CVE-2023-54140

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-54140/
Summaries are generated and may contain mistakes; the official description above is the record.