ACPICA: Fix to handle NULL package elements correctly

Fixed problem where NULL package elements were not returned to
the AcpiEvaluateObject interface correctly. Instead of returning a
NULL ACPI_OBJECT package element, the element was simply ignored,
potentially causing a buffer overflow and/or confusing the caller
who expected a fixed number of elements.

http://bugzilla.kernel.org/show_bug.cgi?id=10132

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>

2 files changed, 19 insertions, 15 deletions

diff --git a/drivers/acpi/utilities/utobject.c b/drivers/acpi/utilities/utobject.c
index 1eccd3db876f..cdb8ff5b92d1 100644
--- a/drivers/acpi/utilities/utobject.c
+++ b/drivers/acpi/utilities/utobject.c
@@ -470,9 +470,8 @@ acpi_ut_get_simple_object_size(union acpi_operand_object *internal_object,
 	case ACPI_TYPE_PROCESSOR:
 	case ACPI_TYPE_POWER:
 
-		/*
-		 * No extra data for these types
-		 */
+		/* No extra data for these types */
+
 		break;
 
 	case ACPI_TYPE_LOCAL_REFERENCE:
diff --git a/include/acpi/actypes.h b/include/acpi/actypes.h
index 599657eac2d4..75ec153338e7 100644
--- a/include/acpi/actypes.h
+++ b/include/acpi/actypes.h
@@ -639,46 +639,51 @@ typedef u8 acpi_adr_space_type;
 /*
  * External ACPI object definition
  */
+
+/*
+ * Note: Type == ACPI_TYPE_ANY (0) is used to indicate a NULL package element
+ * or an unresolved named reference.
+ */
 union acpi_object {
 	acpi_object_type type;	/* See definition of acpi_ns_type for values */
 	struct {
-		acpi_object_type type;
+		acpi_object_type type;	/* ACPI_TYPE_INTEGER */
 		acpi_integer value;	/* The actual number */
 	} integer;
 
 	struct {
-		acpi_object_type type;
+		acpi_object_type type;	/* ACPI_TYPE_STRING */
 		u32 length;	/* # of bytes in string, excluding trailing null */
 		char *pointer;	/* points to the string value */
 	} string;
 
 	struct {
-		acpi_object_type type;
+		acpi_object_type type;	/* ACPI_TYPE_BUFFER */
 		u32 length;	/* # of bytes in buffer */
 		u8 *pointer;	/* points to the buffer */
 	} buffer;
 
 	struct {
-		acpi_object_type type;
-		u32 fill1;
-		acpi_handle handle;	/* object reference */
-	} reference;
-
-	struct {
-		acpi_object_type type;
+		acpi_object_type type;	/* ACPI_TYPE_PACKAGE */
 		u32 count;	/* # of elements in package */
 		union acpi_object *elements;	/* Pointer to an array of ACPI_OBJECTs */
 	} package;
 
 	struct {
-		acpi_object_type type;
+		acpi_object_type type;	/* ACPI_TYPE_LOCAL_REFERENCE */
+		acpi_object_type actual_type;	/* Type associated with the Handle */
+		acpi_handle handle;	/* object reference */
+	} reference;
+
+	struct {
+		acpi_object_type type;	/* ACPI_TYPE_PROCESSOR */
 		u32 proc_id;
 		acpi_io_address pblk_address;
 		u32 pblk_length;
 	} processor;
 
 	struct {
-		acpi_object_type type;
+		acpi_object_type type;	/* ACPI_TYPE_POWER */
 		u32 system_level;
 		u32 resource_order;
 	} power_resource;