# CVE-2023-54185: btrfs: remove BUG_ON()'s in add_new_free_space()

> A local attacker can trigger a kernel crash in the btrfs filesystem by exploiting missing error handling in free space management, causing a 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:** 30 Dec 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2023-54185, DEBIAN-CVE-2023-54185, GHSA-px78-h2pc-q658, ROOT-OS-DEBIAN-11-CVE-2023-54185, ROOT-OS-UBUNTU-2204-CVE-2023-54185, UBUNTU-CVE-2023-54185

## What is CVE-2023-54185?

CVE-2023-54185 is a denial of service vulnerability in Linux, published on 30 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:

btrfs: remove BUG_ON()'s in add_new_free_space()

At add_new_free_space() we have these BUG_ON()'s that are there to deal
with any failure to add free space to the in memory free space cache.
Such failures are mostly -ENOMEM that should be very rare. However there's
no need to have these BUG_ON()'s, we can just return any error to the
caller and all callers and their upper call chain are already dealing with
errors.

So just make add_new_free_space() return any errors, while removing the
BUG_ON()'s, and returning the total amount of added free space to an
optional u64 pointer argument.

## Which versions are affected by CVE-2023-54185?


## How do I fix CVE-2023-54185?

Apply the vendor's patch.

## Is CVE-2023-54185 being exploited?

There is no known exploitation of CVE-2023-54185 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-54185 and fix it if it is affected.

What it is: CVE-2023-54185 is a denial of service vulnerability in Linux, published on 30 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-2023-54185 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-2023-54185/ (Markdown: https://insights.sbomify.com/CVE-2023-54185/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-54185
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-54185
- OSV: https://osv.dev/vulnerability/CVE-2023-54185

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-54185/
Summaries are generated and may contain mistakes; the official description above is the record.