4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Joerg Roedel <jroedel@xxxxxxx> commit e3d5092b6756b9e0b08f94bbeafcc7afe19f0996 upstream. The on-stack resource-window 'win' in setup_res() is not properly initialized. This causes the pointers in the embedded 'struct resource' to contain stale addresses. These pointers (in my case the ->child pointer) later get propagated to the global iomem_resources list, causing a #GP exception when the list is traversed in iomem_map_sanity_check(). Fixes: c183619b63ec (x86/irq, ACPI: Implement ACPI driver to support IOAPIC hotplug) Signed-off-by: Joerg Roedel <jroedel@xxxxxxx> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/acpi/ioapic.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/drivers/acpi/ioapic.c +++ b/drivers/acpi/ioapic.c @@ -45,6 +45,12 @@ static acpi_status setup_res(struct acpi struct resource *res = data; struct resource_win win; + /* + * We might assign this to 'res' later, make sure all pointers are + * cleared before the resource is added to the global list + */ + memset(&win, 0, sizeof(win)); + res->flags = 0; if (acpi_dev_filter_resource_type(acpi_res, IORESOURCE_MEM) == 0) return AE_OK;