From 8805840aad73df7146778be243a196d48b4f6430 Mon Sep 17 00:00:00 2001 From: Angel J Date: Fri, 18 Sep 2026 14:55:40 -0500 Subject: 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 [bhelgaas: move pdev->subordinate test to callees, commit log] Signed-off-by: Bjorn Helgaas Cc: stable@vger.kernel.org # v6.6+ Link: https://patch.msgid.link/20260918195540.GA1187209@bhelgaas --- drivers/pci/of_property.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/pci/of_property.c b/drivers/pci/of_property.c index 75a358f73..1500740cc 100644 --- a/drivers/pci/of_property.c +++ b/drivers/pci/of_property.c @@ -95,9 +95,13 @@ static int of_pci_prop_bus_range(struct pci_dev *pdev, struct of_changeset *ocs, struct device_node *np) { - u32 bus_range[] = { pdev->subordinate->busn_res.start, - pdev->subordinate->busn_res.end }; + u32 bus_range[2]; + if (!pdev->subordinate) + return 0; + + bus_range[0] = pdev->subordinate->busn_res.start; + bus_range[1] = pdev->subordinate->busn_res.end; return of_changeset_add_prop_u32_array(ocs, np, "bus-range", bus_range, ARRAY_SIZE(bus_range)); } @@ -220,6 +224,9 @@ static int of_pci_prop_intr_map(struct pci_dev *pdev, struct of_changeset *ocs, int ret; u8 pin; + if (!pdev->subordinate) + return 0; + pnode = pci_device_to_OF_node(pdev->bus->self); if (!pnode) pnode = pci_bus_to_OF_node(pdev->bus); -- cgit v1.3.1