Ticket #43417: 43417.diff

src/wp-includes/functions.php

@@ -1680 +1680 @@
         // We need to find the permissions of the parent folder that exists and inherit that.
         $target_parent = dirname( $target );
         while ( '.' != $target_parent && ! is_dir( $target_parent ) ) {
+                // Infinite loop protection (see https://core.trac.wordpress.org/ticket/43417)
+                if ( dirname( $target_parent ) === $target_parent ) {
+                        break;
+                }
                 $target_parent = dirname( $target_parent );
         }