# CVE-2023-53804: nilfs2: fix use-after-free bug of nilfs_root in nilfs_evict_inode()

> A use-after-free bug in the nilfs2 filesystem allows attackers to cause denial of service or potentially execute code during unmount operations.

- **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:** 9 Dec 2025
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2023-53804, DEBIAN-CVE-2023-53804, GHSA-wf2j-c3q8-8c84, UBUNTU-CVE-2023-53804

## What is CVE-2023-53804?

CVE-2023-53804 is a high-severity use after free vulnerability in Linux, published on 9 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 use-after-free bug of nilfs_root in nilfs_evict_inode()

During unmount process of nilfs2, nothing holds nilfs_root structure after
nilfs2 detaches its writer in nilfs_detach_log_writer().  However, since
nilfs_evict_inode() uses nilfs_root for some cleanup operations, it may
cause use-after-free read if inodes are left in "garbage_list" and
released by nilfs_dispose_list() at the end of nilfs_detach_log_writer().

Fix this issue by modifying nilfs_evict_inode() to only clear inode
without additional metadata changes that use nilfs_root if the file system
is degraded to read-only or the writer is detached.

## Which versions are affected by CVE-2023-53804?


## How do I fix CVE-2023-53804?

Apply the vendor's patch.

## Is CVE-2023-53804 being exploited?

There is no known exploitation of CVE-2023-53804 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-53804 and fix it if it is affected.

What it is: CVE-2023-53804 is a high-severity use after free vulnerability in Linux, published on 9 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-2023-53804 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-2023-53804/ (Markdown: https://insights.sbomify.com/CVE-2023-53804/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53804
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53804
- OSV: https://osv.dev/vulnerability/CVE-2023-53804

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53804/
Summaries are generated and may contain mistakes; the official description above is the record.