ACPICA: Prevent possible allocation overrun during object copy

[safe/jmp/linux-2.6] / drivers / acpi / acpica / utcopy.c

diff --git a/drivers/acpi/acpica/utcopy.c b/drivers/acpi/acpica/utcopy.c
index 97ec362..6fef83f 100644 (file)
--- a/drivers/acpi/acpica/utcopy.c
+++ b/drivers/acpi/acpica/utcopy.c
@@ -677,16 +677,24 @@ acpi_ut_copy_simple_object(union acpi_operand_object *source_desc,
        u16 reference_count;
        union acpi_operand_object *next_object;
        acpi_status status;
+       acpi_size copy_size;
 
        /* Save fields from destination that we don't want to overwrite */
 
        reference_count = dest_desc->common.reference_count;
        next_object = dest_desc->common.next_object;
 
-       /* Copy the entire source object over the destination object */
+       /*
+        * Copy the entire source object over the destination object.
+        * Note: Source can be either an operand object or namespace node.
+        */
+       copy_size = sizeof(union acpi_operand_object);
+       if (ACPI_GET_DESCRIPTOR_TYPE(source_desc) == ACPI_DESC_TYPE_NAMED) {
+               copy_size = sizeof(struct acpi_namespace_node);
+       }
 
-       ACPI_MEMCPY((char *)dest_desc, (char *)source_desc,
-                   sizeof(union acpi_operand_object));
+       ACPI_MEMCPY(ACPI_CAST_PTR(char, dest_desc),
+                   ACPI_CAST_PTR(char, source_desc), copy_size);
 
        /* Restore the saved fields */