Commit 6fcab279 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

ACPICA: Refuse to evaluate a method if arguments are missing 

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: default avatarPeter Williams <peter@newton.cx>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: default avatarHans de Goede <hansg@kernel.org>
Tested-by: Hans de Goede <hansg@kernel.org> # Dell XPS 9640 with BIOS 1.12.0
Link: https://patch.msgid.link/5909446.DvuYhMxLoT@rjwysocki.net


Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent e04c78d8

drivers/acpi/acpica/dsmethod.c

+7 −0
Original line number Diff line number Diff line
@@ -483,6 +483,13 @@ acpi_ds_call_control_method(struct acpi_thread_state *thread, 
		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 =