# CVE-2025-71269: btrfs: do not free data reservation in fallback from inline due to -ENOSPC

> A use-after-free vulnerability in the Linux kernel's btrfs filesystem allows attackers to cause denial of service or potentially execute code via crafted filesystem operations.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 Mar 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-80085, BELL-CVE-2025-71269, DEBIAN-CVE-2025-71269, GHSA-wqgp-m495-6968, ROOT-OS-DEBIAN-11-CVE-2025-71269, ROOT-OS-DEBIAN-12-CVE-2025-71269, ROOT-OS-DEBIAN-13-CVE-2025-71269, ROOT-OS-UBUNTU-2204-CVE-2025-71269, ROOT-OS-UBUNTU-2404-CVE-2025-71269, UBUNTU-CVE-2025-71269

## What is CVE-2025-71269?

CVE-2025-71269 is a high-severity use after free vulnerability in Linux kernel, published on 18 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

btrfs: do not free data reservation in fallback from inline due to -ENOSPC

If we fail to create an inline extent due to -ENOSPC, we will attempt to
go through the normal COW path, reserve an extent, create an ordered
extent, etc. However we were always freeing the reserved qgroup data,
which is wrong since we will use data. Fix this by freeing the reserved
qgroup data in __cow_file_range_inline() only if we are not doing the
fallback (ret is <= 0).

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2025-71269?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-71269?

Apply the vendor's patch.

## Is CVE-2025-71269 being exploited?

There is no known exploitation of CVE-2025-71269 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-71269 and fix it if it is affected.

What it is: CVE-2025-71269 is a high-severity use after free vulnerability in Linux kernel, published on 18 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-71269 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2025-71269/ (Markdown: https://insights.sbomify.com/CVE-2025-71269/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-71269
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-71269
- OSV: https://osv.dev/vulnerability/CVE-2025-71269

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-71269/
Summaries are generated and may contain mistakes; the official description above is the record.