ACPICA: Avoid walking the ACPI Namespace if it is not there

rafaeljw · rafaeljw · commit 0c9992315e73 · 2022-03-07T20:28:26.000+01:00
ACPICA commit b1c3656ef4950098e530be68d4b589584f06cddc Prevent acpi_ns_walk_namespace() from crashing when called with start_node equal to ACPI_ROOT_OBJECT if the Namespace has not been instantiated yet and acpi_gbl_root_node is NULL. For instance, this can happen if the kernel is run with "acpi=off" in the command line. Link: acpica/acpica@b1c3656 Link: https://lore.kernel.org/linux-acpi/CAJZ5v0hJWW_vZ3wwajE7xT38aWjY7cZyvqMJpXHzUL98-SiCVQ@mail.gmail.com/ Reported-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/acpi/acpica/nswalk.c b/drivers/acpi/acpica/nswalk.c
@@ -169,6 +169,9 @@ acpi_ns_walk_namespace(acpi_object_type type,
 
 	if (start_node == ACPI_ROOT_OBJECT) {
 		start_node = acpi_gbl_root_node;
+		if (!start_node) {
+			return_ACPI_STATUS(AE_NO_NAMESPACE);
+		}
 	}
 
 	/* Null child means "get first node" */

Original file line number	Diff line number	Diff line change
`@@ -169,6 +169,9 @@ acpi_ns_walk_namespace(acpi_object_type type,`
`169`	`169`
`170`	`170`	`if (start_node == ACPI_ROOT_OBJECT) {`
`171`	`171`	`start_node = acpi_gbl_root_node;`
	`172`	`+ if (!start_node) {`
	`173`	`+ return_ACPI_STATUS(AE_NO_NAMESPACE);`
	`174`	`+ }`
`172`	`175`	`}`
`173`	`176`
`174`	`177`	`/* Null child means "get first node" */`