# CVE-2025-21831: PCI: Avoid putting some root ports into D3 on TUXEDO Sirius Gen1

> A kernel bug causes system hangs during suspend on specific TUXEDO hardware, requiring a patch to prevent root ports from entering D3 state.

- **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:** 6 Mar 2025
- **Updated:** 11 May 2026
- **Also known as:** AZL-69009, BELL-CVE-2025-21831, DEBIAN-CVE-2025-21831, GHSA-m4j5-fq6h-r8gv, ROOT-OS-DEBIAN-11-CVE-2025-21831, ROOT-OS-DEBIAN-12-CVE-2025-21831, ROOT-OS-UBUNTU-2204-CVE-2025-21831, UBUNTU-CVE-2025-21831

## What is CVE-2025-21831?

CVE-2025-21831 is a medium-severity denial of service vulnerability in Linux kernel, published on 6 Mar 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: Avoid putting some root ports into D3 on TUXEDO Sirius Gen1

commit 9d26d3a8f1b0 ("PCI: Put PCIe ports into D3 during suspend") sets the
policy that all PCIe ports are allowed to use D3.  When the system is
suspended if the port is not power manageable by the platform and won't be
used for wakeup via a PME this sets up the policy for these ports to go
into D3hot.

This policy generally makes sense from an OSPM perspective but it leads to
problems with wakeup from suspend on the TUXEDO Sirius 16 Gen 1 with a
specific old BIOS. This manifests as a system hang.

On the affected Device + BIOS combination, add a quirk for the root port of
the problematic controller to ensure that these root ports are not put into
D3hot at suspend.

This patch is based on

  https://lore.kernel.org/linux-pci/20230708214457.1229-2-mario.limonciello@amd.com

but with the added condition both in the documentation and in the code to
apply only to the TUXEDO Sirius 16 Gen 1 with a specific old BIOS and only
the affected root ports.

## Which versions are affected by CVE-2025-21831?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-21831?

Apply the vendor's patch.

## Is CVE-2025-21831 being exploited?

There is no known exploitation of CVE-2025-21831 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-2025-21831 and fix it if it is affected.

What it is: CVE-2025-21831 is a medium-severity denial of service vulnerability in Linux kernel, published on 6 Mar 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-2025-21831 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-2025-21831/ (Markdown: https://insights.sbomify.com/CVE-2025-21831/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-21831
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-21831
- OSV: https://osv.dev/vulnerability/CVE-2025-21831

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-21831/
Summaries are generated and may contain mistakes; the official description above is the record.