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| author | Angel J <iamanaws@httpd.dev> | 2026-09-18 14:55:40 -0500 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2026-09-18 15:19:20 -0500 |
| commit | 8805840aad73df7146778be243a196d48b4f6430 (patch) | |
| tree | 12c27341c693c7a4345dc2fb923dd15b41b7dc69 | |
| parent | d58384c22739848efe14b34e9586e4f1242f33c0 (diff) | |
| download | linux-stable-8805840aad73df7146778be243a196d48b4f6430.tar.gz linux-stable-8805840aad73df7146778be243a196d48b4f6430.zip | |
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>
Cc: stable@vger.kernel.org # v6.6+
Link: https://patch.msgid.link/20260918195540.GA1187209@bhelgaas
| -rw-r--r-- | drivers/pci/of_property.c | 11 |
1 files 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); |