ACPICA: Fix possible memory leak for Scope ASL operator

Using Scope(\) to change the scope to the root could cause a
single object memory leak.

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

1 files changed, 33 insertions, 17 deletions

diff --git a/drivers/acpi/acpica/dswload.c b/drivers/acpi/acpica/dswload.c
index 6de3a99d4cd4..10fc78517843 100644
--- a/drivers/acpi/acpica/dswload.c
+++ b/drivers/acpi/acpica/dswload.c
@@ -639,26 +639,42 @@ acpi_ds_load2_begin_op(struct acpi_walk_state *walk_state,
                 break;
 
         case AML_SCOPE_OP:
-                /*
-                 * The Path is an object reference to an existing object.
-                 * Don't enter the name into the namespace, but look it up
-                 * for use later.
-                 */
-                status =
-                    acpi_ns_lookup(walk_state->scope_info, buffer_ptr,
-                                   object_type, ACPI_IMODE_EXECUTE,
-                                   ACPI_NS_SEARCH_PARENT, walk_state, &(node));
-                if (ACPI_FAILURE(status)) {
-#ifdef ACPI_ASL_COMPILER
-                        if (status == AE_NOT_FOUND) {
-                                status = AE_OK;
-                        } else {
-                                ACPI_ERROR_NAMESPACE(buffer_ptr, status);
+
+                /* Special case for Scope(\) -> refers to the Root node */
+
+                if (op && (op->named.node == acpi_gbl_root_node)) {
+                        node = op->named.node;
+
+                        status =
+                            acpi_ds_scope_stack_push(node, object_type,
+                                                     walk_state);
+                        if (ACPI_FAILURE(status)) {
+                                return_ACPI_STATUS(status);
                         }
+                } else {
+                        /*
+                         * The Path is an object reference to an existing object.
+                         * Don't enter the name into the namespace, but look it up
+                         * for use later.
+                         */
+                        status =
+                            acpi_ns_lookup(walk_state->scope_info, buffer_ptr,
+                                           object_type, ACPI_IMODE_EXECUTE,
+                                           ACPI_NS_SEARCH_PARENT, walk_state,
+                                           &(node));
+                        if (ACPI_FAILURE(status)) {
+#ifdef ACPI_ASL_COMPILER
+                                if (status == AE_NOT_FOUND) {
+                                        status = AE_OK;
+                                } else {
+                                        ACPI_ERROR_NAMESPACE(buffer_ptr,
+                                                             status);
+                                }
 #else
-                        ACPI_ERROR_NAMESPACE(buffer_ptr, status);
+                                ACPI_ERROR_NAMESPACE(buffer_ptr, status);
 #endif
-                        return_ACPI_STATUS(status);
+                                return_ACPI_STATUS(status);
+                        }
                 }
 
                 /*