Re: [PATCH v3] PCI: of_property: Omit bus properties without a subordinate bus

[sashiko-bot@kernel.org]

> Author: Angel J <iamanaws@httpd.dev>
> 
> 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.
> 
> Fixes: 407d1a51921e ("PCI: Create device tree node for bridge")
> Signed-off-by: Angel J <iamanaws@httpd.dev>
> [bhelgaas: move pdev->subordinate test to callees, commit log]
> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20260918195540.GA1187209@bhelgaas?part=1