1 files changed, 13 insertions, 2 deletions

diff --git a/drivers/acpi/utilities/utmisc.c b/drivers/acpi/utilities/utmisc.c
index f0275025b718..0c5abc536c7a 100644
--- a/drivers/acpi/utilities/utmisc.c
+++ b/drivers/acpi/utilities/utmisc.c
@@ -67,6 +67,14 @@ acpi_status acpi_ut_allocate_owner_id(acpi_owner_id * owner_id)
 
         ACPI_FUNCTION_TRACE("ut_allocate_owner_id");
 
+        /* Guard against multiple allocations of ID to the same location */
+
+        if (*owner_id) {
+                ACPI_REPORT_ERROR(("Owner ID [%2.2X] already exists\n",
+                                   *owner_id));
+                return_ACPI_STATUS(AE_ALREADY_EXISTS);
+        }
+
         /* Mutex for the global ID mask */
 
         status = acpi_ut_acquire_mutex(ACPI_MTX_CACHES);
@@ -80,7 +88,8 @@ acpi_status acpi_ut_allocate_owner_id(acpi_owner_id * owner_id)
                 if (!(acpi_gbl_owner_id_mask & (1 << i))) {
                         ACPI_DEBUG_PRINT((ACPI_DB_VALUES,
                                           "Current owner_id mask: %8.8X New ID: %2.2X\n",
-                                          acpi_gbl_owner_id_mask, (i + 1)));
+                                          acpi_gbl_owner_id_mask,
+                                          (unsigned int)(i + 1)));
 
                         acpi_gbl_owner_id_mask |= (1 << i);
                         *owner_id = (acpi_owner_id) (i + 1);
@@ -143,7 +152,9 @@ void acpi_ut_release_owner_id(acpi_owner_id * owner_id_ptr)
                 return_VOID;
         }
 
-        owner_id--;             /* Normalize to zero */
+        /* Normalize the ID to zero */
+
+        owner_id--;
 
         /* Free the owner ID only if it is valid */