8296692: Improve String platform support

Reviewed-by: mbalao
Backport-of: ed8643947e21263588cb6e9202efb3a30f450c4e

Author: Ekaterina Vergizova

src/jdk.management.agent/unix/classes/jdk/internal/agent/FileSystemImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2004, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2004, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -29,7 +29,7 @@
 import java.io.IOException;
 
 /*
- * Solaris/Linux implementation of jdk.internal.agent.FileSystem
+ * Linux implementation of jdk.internal.agent.FileSystem
  */
 @SuppressWarnings("removal")
 public class FileSystemImpl extends FileSystem {
@@ -39,6 +39,10 @@ public boolean supportsFileSecurity(File f) throws IOException {
     }
 
     public boolean isAccessUserOnly(File f) throws IOException {
+        String path = f.getPath();
+        if (path.indexOf(0) >= 0) {
+            throw new IOException("illegal filename");
+        }
         return isAccessUserOnly0(f.getPath());
     }
 

src/jdk.management.agent/windows/classes/jdk/internal/agent/FileSystemImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2004, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2004, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -35,11 +35,18 @@
 public class FileSystemImpl extends FileSystem {
 
     public boolean supportsFileSecurity(File f) throws IOException {
+        String path = f.getAbsolutePath();
+        if (path.indexOf(0) >= 0) {
+            throw new IOException("illegal filename");
+        }
         return isSecuritySupported0(f.getAbsolutePath());
     }
 
     public boolean isAccessUserOnly(File f) throws IOException {
         String path = f.getAbsolutePath();
+        if (path.indexOf(0) >= 0) {
+            throw new IOException("illegal filename");
+        }
         if (!isSecuritySupported0(path)) {
             throw new UnsupportedOperationException("File system does not support file security");
         }