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.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
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.
Sources
Also known as AZL-109424, BELL-CVE-2026-98504, DEBIAN-CVE-2026-98504, GHSA-56f2-rw4q-8x32, UBUNTU-CVE-2026-98504.