# CVE-2024-42314: btrfs: fix extent map use-after-free when adding pages to compressed bio

> A use-after-free in the Linux kernel's btrfs filesystem allows attackers to potentially execute code or escalate privileges.

- **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:** 17 Aug 2024
- **Updated:** 5 Aug 2026
- **Also known as:** AZL-48018, BELL-CVE-2024-42314, DEBIAN-CVE-2024-42314, GHSA-j3xp-78w6-p4vh, UBUNTU-CVE-2024-42314

## What is CVE-2024-42314?

CVE-2024-42314 is a high-severity use after free vulnerability in Debian Debian Linux, published on 17 Aug 2024. 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 extent map use-after-free when adding pages to compressed bio

At add_ra_bio_pages() we are accessing the extent map to calculate
'add_size' after we dropped our reference on the extent map, resulting
in a use-after-free. Fix this by computing 'add_size' before dropping our
extent map reference.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2024-42314?

It affects 2 products.


Products: Debian Debian Linux, Linux kernel.

## How do I fix CVE-2024-42314?

Apply the vendor's patch.

## Is CVE-2024-42314 being exploited?

There is no known exploitation of CVE-2024-42314 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-42314 and fix it if it is affected.

What it is: CVE-2024-42314 is a high-severity use after free vulnerability in Debian Debian Linux, published on 17 Aug 2024. 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-2024-42314 in the wild and no public exploit code.

Affected product: Debian Debian 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-2024-42314/ (Markdown: https://insights.sbomify.com/CVE-2024-42314/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-42314
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-42314
- OSV: https://osv.dev/vulnerability/CVE-2024-42314

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-42314/
Summaries are generated and may contain mistakes; the official description above is the record.