From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> As reported in [1], a platform firmware update that increased the number of method parameters and forgot to update a least one of its callers, caused ACPICA to crash due to use-after-free. Since this a result of a clear AML issue that arguably cannot be fixed up by the interpreter (it cannot produce missing data out of thin air), address it by making ACPICA refuse to evaluate a method if the caller attempts to pass fewer arguments than expected to it. Closes: https://github.com/acpica/acpica/issues/1027 [1] Reported-by: Peter Williams <peter@xxxxxxxxx> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> --- This is an exception as it fixes a kernel crash on multiple platforms affected by the defective platform firmware update. I will take care of submitting an equivalent change to upstream ACPICA later. --- drivers/acpi/acpica/dsmethod.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/drivers/acpi/acpica/dsmethod.c +++ b/drivers/acpi/acpica/dsmethod.c @@ -483,6 +483,13 @@ return_ACPI_STATUS(AE_NULL_OBJECT); } + if (this_walk_state->num_operands < obj_desc->method.param_count) { + ACPI_ERROR((AE_INFO, "Missing argument for method [%4.4s]", + acpi_ut_get_node_name(method_node))); + + return_ACPI_STATUS(AE_AML_UNINITIALIZED_ARG); + } + /* Init for new method, possibly wait on method mutex */ status =
