The acpi_ns_get_attached_object() function may return NULL, which may cause null pointer deference, and most other callsites of acpi_ns_get_attached_object() do Null check. Add Null check for return value of acpi_ns_get_attached_object(). Found by our static analysis tool. Signed-off-by: Chenyuan Mi <cymi20@xxxxxxxxxxxx> --- drivers/acpi/acpica/exprep.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/acpi/acpica/exprep.c b/drivers/acpi/acpica/exprep.c index 08196fa17080..d9c006ec1ac8 100644 --- a/drivers/acpi/acpica/exprep.c +++ b/drivers/acpi/acpica/exprep.c @@ -431,6 +431,13 @@ acpi_status acpi_ex_prep_field_value(struct acpi_create_field_info *info) obj_desc->field.region_obj = acpi_ns_get_attached_object(info->region_node); + if (!obj_desc->field.region_obj) { + ACPI_ERROR((AE_INFO, + "Null Region Object during field prep")); + acpi_ut_delete_object_desc(obj_desc); + return_ACPI_STATUS(AE_AML_INTERNAL); + } + /* Fields specific to generic_serial_bus fields */ obj_desc->field.access_length = info->access_length; -- 2.17.1