If acpi_bus_add does not return a device and it's passed to acpi_bus_start, bad things will happen: BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 IP: [<ffffffff8128402d>] acpi_bus_start+0x14/0x24 ... [<ffffffffa008977a>] acpiphp_bus_add+0xba/0x130 [acpiphp] [<ffffffffa008aa72>] enable_device+0x132/0x2ff [acpiphp] [<ffffffffa0089b68>] acpiphp_enable_slot+0xb8/0x130 [acpiphp] [<ffffffffa0089df7>] handle_hotplug_event_func+0x87/0x190 [acpiphp] Next patch would make this NULL pointer check obsolete, but better having one more than one missing... Signed-off-by: Thomas Renninger <trenn@xxxxxxx> CC: bjorn.helgaas@xxxxxx CC: lenb@xxxxxxxxxx CC: linux-acpi@xxxxxxxxxxxxxxx CC: kristen.c.accardi@xxxxxxxxx CC: stable@xxxxxxxxxx --- drivers/acpi/scan.c | 3 +++ 1 file changed, 3 insertions(+) Index: linux-2.6.32-SLE11-SP1/drivers/acpi/scan.c =================================================================== --- linux-2.6.32-SLE11-SP1.orig/drivers/acpi/scan.c +++ linux-2.6.32-SLE11-SP1/drivers/acpi/scan.c @@ -1382,6 +1382,9 @@ int acpi_bus_start(struct acpi_device *d { struct acpi_bus_ops ops; + if (!device) + return -EINVAL; + memset(&ops, 0, sizeof(ops)); ops.acpi_op_start = 1; -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html