ACPICA: Fixes for parameter validation.

Extra checks for valid handle/path combinations, BZ 478

Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 24 insertions, 21 deletions

diff --git a/drivers/acpi/namespace/nsxfname.c b/drivers/acpi/namespace/nsxfname.c
index 978213a6c19f..408bd1145728 100644
--- a/drivers/acpi/namespace/nsxfname.c
+++ b/drivers/acpi/namespace/nsxfname.c
@@ -84,38 +84,41 @@ acpi_get_handle(acpi_handle parent,
         /* Convert a parent handle to a prefix node */
 
         if (parent) {
-                status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
-                if (ACPI_FAILURE(status)) {
-                        return (status);
-                }
-
                 prefix_node = acpi_ns_map_handle_to_node(parent);
                 if (!prefix_node) {
-                        (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
                         return (AE_BAD_PARAMETER);
                 }
+        }
+
+        /*
+         * Valid cases are:
+         * 1) Fully qualified pathname
+         * 2) Parent + Relative pathname
+         *
+         * Error for <null Parent + relative path>
+         */
+        if (acpi_ns_valid_root_prefix(pathname[0])) {
 
-                status = acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
-                if (ACPI_FAILURE(status)) {
-                        return (status);
+                /* Pathname is fully qualified (starts with '\') */
+
+                /* Special case for root-only, since we can't search for it */
+
+                if (!ACPI_STRCMP(pathname, ACPI_NS_ROOT_PATH)) {
+                        *ret_handle =
+                            acpi_ns_convert_entry_to_handle(acpi_gbl_root_node);
+                        return (AE_OK);
                 }
-        }
+        } else if (!prefix_node) {
 
-        /* Special case for root, since we can't search for it */
+                /* Relative path with null prefix is disallowed */
 
-        if (ACPI_STRCMP(pathname, ACPI_NS_ROOT_PATH) == 0) {
-                *ret_handle =
-                    acpi_ns_convert_entry_to_handle(acpi_gbl_root_node);
-                return (AE_OK);
+                return (AE_BAD_PARAMETER);
         }
 
-        /*
-         *  Find the Node and convert to a handle
-         */
-        status = acpi_ns_get_node(prefix_node, pathname, ACPI_NS_NO_UPSEARCH,
-                                  &node);
+        /* Find the Node and convert to a handle */
 
-        *ret_handle = NULL;
+        status =
+            acpi_ns_get_node(prefix_node, pathname, ACPI_NS_NO_UPSEARCH, &node);
         if (ACPI_SUCCESS(status)) {
                 *ret_handle = acpi_ns_convert_entry_to_handle(node);
         }