# CVE-2025-23161: PCI: vmd: Make vmd_dev::cfg_lock a raw_spinlock_t type

> A locking bug in the Linux kernel VMD driver causes a crash when accessing PCI config space on PREEMPT_RT systems, leading to 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:** 1 May 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2025-23161, DEBIAN-CVE-2025-23161, GHSA-q3v6-chw5-g495, ROOT-OS-DEBIAN-11-CVE-2025-23161, ROOT-OS-DEBIAN-12-CVE-2025-23161, ROOT-OS-UBUNTU-2204-CVE-2025-23161, ROOT-OS-UBUNTU-2404-CVE-2025-23161, UBUNTU-CVE-2025-23161

## What is CVE-2025-23161?

CVE-2025-23161 is a medium-severity denial of service vulnerability in Debian Debian Linux, published on 1 May 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:

PCI: vmd: Make vmd_dev::cfg_lock a raw_spinlock_t type

The access to the PCI config space via pci_ops::read and pci_ops::write is
a low-level hardware access. The functions can be accessed with disabled
interrupts even on PREEMPT_RT. The pci_lock is a raw_spinlock_t for this
purpose.

A spinlock_t becomes a sleeping lock on PREEMPT_RT, so it cannot be
acquired with disabled interrupts. The vmd_dev::cfg_lock is accessed in
the same context as the pci_lock.

Make vmd_dev::cfg_lock a raw_spinlock_t type so it can be used with
interrupts disabled.

This was reported as:

  BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
  Call Trace:
   rt_spin_lock+0x4e/0x130
   vmd_pci_read+0x8d/0x100 [vmd]
   pci_user_read_config_byte+0x6f/0xe0
   pci_read_config+0xfe/0x290
   sysfs_kf_bin_read+0x68/0x90

[bigeasy: reword commit message]
Tested-off-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
[kwilczynski: commit log]
[bhelgaas: add back report info from
https://lore.kernel.org/lkml/20241218115951.83062-1-ryotkkr98@gmail.com/]

Weakness: CWE-667 (Improper Locking)

## Which versions are affected by CVE-2025-23161?

It affects 2 products.


Products: Debian Debian Linux, Linux kernel.

## How do I fix CVE-2025-23161?

Apply the vendor's patch.

## Is CVE-2025-23161 being exploited?

There is no known exploitation of CVE-2025-23161 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-2025-23161 and fix it if it is affected.

What it is: CVE-2025-23161 is a medium-severity denial of service vulnerability in Debian Debian Linux, published on 1 May 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-2025-23161 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-2025-23161/ (Markdown: https://insights.sbomify.com/CVE-2025-23161/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-23161
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-23161
- OSV: https://osv.dev/vulnerability/CVE-2025-23161

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-23161/
Summaries are generated and may contain mistakes; the official description above is the record.