static PCIBus *acpi_pcihp_find_hotplug_bus(AcpiPciHpState *s, int bsel)
{
    AcpiPciHpFind find = { .bsel = bsel, .bus = NULL };

    if (bsel < 0) {
        return NULL;
    }

    pci_for_each_bus(s->root, acpi_pcihp_test_hotplug_bus, &find);

    /* Make bsel 0 eject root bus if bsel property is not set,
     * for compatibility with non acpi setups.
     * TODO: really needed?
     */
    if (!bsel && !find.bus) {
        find.bus = s->root;
    }
    return find.bus;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.