# CVE-2023-53845: nilfs2: fix infinite loop in nilfs_mdt_get_block()

> A corrupted nilfs2 disk image can cause an infinite loop and system hang in the Linux kernel, leading to denial of service.

- **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:** 9 Dec 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2023-53845, DEBIAN-CVE-2023-53845, GHSA-qv9p-mjrr-3vmm, UBUNTU-CVE-2023-53845

## What is CVE-2023-53845?

CVE-2023-53845 is a denial of service 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 infinite loop in nilfs_mdt_get_block()

If the disk image that nilfs2 mounts is corrupted and a virtual block
address obtained by block lookup for a metadata file is invalid,
nilfs_bmap_lookup_at_level() may return the same internal return code as
-ENOENT, meaning the block does not exist in the metadata file.

This duplication of return codes confuses nilfs_mdt_get_block(), causing
it to read and create a metadata block indefinitely.

In particular, if this happens to the inode metadata file, ifile,
semaphore i_rwsem can be left held, causing task hangs in lock_mount.

Fix this issue by making nilfs_bmap_lookup_at_level() treat virtual block
address translation failures with -ENOENT as metadata corruption instead
of returning the error code.

## Which versions are affected by CVE-2023-53845?


## How do I fix CVE-2023-53845?

Apply the vendor's patch.

## Is CVE-2023-53845 being exploited?

There is no known exploitation of CVE-2023-53845 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-53845 and fix it if it is affected.

What it is: CVE-2023-53845 is a denial of service 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-2023-53845 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-2023-53845/ (Markdown: https://insights.sbomify.com/CVE-2023-53845/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53845
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53845
- OSV: https://osv.dev/vulnerability/CVE-2023-53845

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53845/
Summaries are generated and may contain mistakes; the official description above is the record.