# CVE-2025-38549: efivarfs: Fix memory leak of efivarfs_fs_info in fs_context error paths

> A memory leak in the Linux kernel's efivarfs filesystem can lead to resource exhaustion and denial of service.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:** 16 Aug 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2025-38549, DEBIAN-CVE-2025-38549, GHSA-cgrx-9qvf-wh88, ROOT-OS-UBUNTU-2404-CVE-2025-38549, UBUNTU-CVE-2025-38549

## What is CVE-2025-38549?

CVE-2025-38549 is a medium-severity denial of service vulnerability in Linux kernel, published on 16 Aug 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:

efivarfs: Fix memory leak of efivarfs_fs_info in fs_context error paths

When processing mount options, efivarfs allocates efivarfs_fs_info (sfi)
early in fs_context initialization. However, sfi is associated with the
superblock and typically freed when the superblock is destroyed. If the
fs_context is released (final put) before fill_super is called—such as
on error paths or during reconfiguration—the sfi structure would leak,
as ownership never transfers to the superblock.

Implement the .free callback in efivarfs_context_ops to ensure any
allocated sfi is properly freed if the fs_context is torn down before
fill_super, preventing this memory leak.

Weakness: CWE-401 (Missing Release of Memory after Effective Lifetime)

## Which versions are affected by CVE-2025-38549?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-38549?

Apply the vendor's patch.

## Is CVE-2025-38549 being exploited?

There is no known exploitation of CVE-2025-38549 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-2025-38549 and fix it if it is affected.

What it is: CVE-2025-38549 is a medium-severity denial of service vulnerability in Linux kernel, published on 16 Aug 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-2025-38549 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-2025-38549/ (Markdown: https://insights.sbomify.com/CVE-2025-38549/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-38549
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-38549
- OSV: https://osv.dev/vulnerability/CVE-2025-38549

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-38549/
Summaries are generated and may contain mistakes; the official description above is the record.