# CVE-2026-98504: PCI: of_property: Omit bus properties without a subordinate bus

> A null pointer dereference in the Linux kernel PCI subsystem can cause a boot hang when dynamic OF nodes are enabled and a bridge lacks a subordinate bus.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-109424, BELL-CVE-2026-98504, DEBIAN-CVE-2026-98504, GHSA-56f2-rw4q-8x32, UBUNTU-CVE-2026-98504

## What is CVE-2026-98504?

CVE-2026-98504 is a vulnerability in Linux, published on 18 Oct 2026. 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: of_property: Omit bus properties without a subordinate bus

A bridge (a device with a Type 1 header) may not have a secondary bus
allocated (pdev->subordinate), e.g., if there are no available bus numbers
or the bridge secondary/subordinate bus numbers are not writable.

The dynamic OF helpers of_pci_prop_bus_range() and of_pci_prop_intr_map()
dereference pdev->subordinate without checking it.  When
CONFIG_PCI_DYNAMIC_OF_NODES is enabled, this can cause a NULL pointer
dereference and early boot hang.

Generate 'bus-range' and 'interrupt-map' properties only when a subordinate
bus exists.  Keep the node and its remaining properties for bridges without
one.

The problem was latent since 407d1a51921e ("PCI: Create device tree node
for bridge"), but wasn't reachable until 1f340724419e ("PCI: of: Create
device tree PCI host bridge node"), which appeared in v6.15.  Before
1f340724419e, of_pci_make_dev_node() returned early because the parent OF
node was missing.

[bhelgaas: move pdev->subordinate test to callees, commit log]

## Which versions are affected by CVE-2026-98504?


## How do I fix CVE-2026-98504?

Apply the vendor's patch.

## Is CVE-2026-98504 being exploited?

There is no known exploitation of CVE-2026-98504 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98504 and fix it if it is affected.

What it is: CVE-2026-98504 is a vulnerability in Linux, published on 18 Oct 2026. 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-2026-98504 in the wild and no public exploit code.

Affected product: 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-2026-98504/ (Markdown: https://insights.sbomify.com/CVE-2026-98504/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98504
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98504
- OSV: https://osv.dev/vulnerability/CVE-2026-98504

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98504/
Summaries are generated and may contain mistakes; the official description above is the record.