# CVE-2025-40101: btrfs: fix memory leaks when rejecting a non SINGLE data profile without an RST

> A memory leak in the Linux kernel btrfs filesystem allows local attackers to cause denial of service by exhausting system memory.

- **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 Oct 2025
- **Updated:** 23 May 2026
- **Also known as:** BELL-CVE-2025-40101, DEBIAN-CVE-2025-40101, GHSA-qqwh-7pmj-9xx8, ROOT-OS-DEBIAN-13-CVE-2025-40101, ROOT-OS-UBUNTU-2404-CVE-2025-40101, UBUNTU-CVE-2025-40101

## What is CVE-2025-40101?

CVE-2025-40101 is a memory corruption vulnerability in Linux, published on 30 Oct 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: fix memory leaks when rejecting a non SINGLE data profile without an RST

At the end of btrfs_load_block_group_zone_info() the first thing we do
is to ensure that if the mapping type is not a SINGLE one and there is
no RAID stripe tree, then we return early with an error.

Doing that, though, prevents the code from running the last calls from
this function which are about freeing memory allocated during its
run. Hence, in this case, instead of returning early, we set the ret
value and fall through the rest of the cleanup code.

## Which versions are affected by CVE-2025-40101?


## How do I fix CVE-2025-40101?

Apply the vendor's patch.

## Is CVE-2025-40101 being exploited?

There is no known exploitation of CVE-2025-40101 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-40101 and fix it if it is affected.

What it is: CVE-2025-40101 is a memory corruption vulnerability in Linux, published on 30 Oct 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-2025-40101 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-2025-40101/ (Markdown: https://insights.sbomify.com/CVE-2025-40101/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-40101
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-40101
- OSV: https://osv.dev/vulnerability/CVE-2025-40101

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-40101/
Summaries are generated and may contain mistakes; the official description above is the record.