diff --git a/src/hotspot/share/classfile/modules.cpp b/src/hotspot/share/classfile/modules.cpp
index 7e26febda89f2..a63fbc1eb747e 100644
--- a/src/hotspot/share/classfile/modules.cpp
+++ b/src/hotspot/share/classfile/modules.cpp
@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2016, 2024, Oracle and/or its affiliates. All rights reserved.
+* Copyright (c) 2016, 2025, 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
@@ -628,12 +628,14 @@ void Modules::serialize(SerializeClosure* soc) {
 }
 
 void Modules::dump_native_access_flag() {
+  ResourceMark rm;
   const char* native_access_names = get_native_access_flags_as_sorted_string();
   if (native_access_names != nullptr) {
     _archived_native_access_flags = ArchiveBuilder::current()->ro_strdup(native_access_names);
   }
 }
 
+// Caller needs ResourceMark
 const char* Modules::get_native_access_flags_as_sorted_string() {
   return get_numbered_property_as_sorted_string("jdk.module.enable.native.access");
 }
@@ -641,6 +643,7 @@ const char* Modules::get_native_access_flags_as_sorted_string() {
 void Modules::serialize_native_access_flags(SerializeClosure* soc) {
   soc->do_ptr(&_archived_native_access_flags);
   if (soc->reading()) {
+    ResourceMark rm;
     check_archived_flag_consistency(_archived_native_access_flags, get_native_access_flags_as_sorted_string(), "jdk.module.enable.native.access");
 
     // Don't hold onto the pointer, in case we might decide to unmap the archive.
@@ -649,12 +652,14 @@ void Modules::serialize_native_access_flags(SerializeClosure* soc) {
 }
 
 void Modules::dump_addmods_names() {
+  ResourceMark rm;
   const char* addmods_names = get_addmods_names_as_sorted_string();
   if (addmods_names != nullptr) {
     _archived_addmods_names = ArchiveBuilder::current()->ro_strdup(addmods_names);
   }
 }
 
+// Caller needs ResourceMark
 const char* Modules::get_addmods_names_as_sorted_string() {
   return get_numbered_property_as_sorted_string("jdk.module.addmods");
 }
@@ -662,6 +667,7 @@ const char* Modules::get_addmods_names_as_sorted_string() {
 void Modules::serialize_addmods_names(SerializeClosure* soc) {
   soc->do_ptr(&_archived_addmods_names);
   if (soc->reading()) {
+    ResourceMark rm;
     check_archived_flag_consistency(_archived_addmods_names, get_addmods_names_as_sorted_string(), "jdk.module.addmods");
 
     // Don't hold onto the pointer, in case we might decide to unmap the archive.
@@ -669,8 +675,8 @@ void Modules::serialize_addmods_names(SerializeClosure* soc) {
   }
 }
 
+// Caller needs ResourceMark
 const char* Modules::get_numbered_property_as_sorted_string(const char* property) {
-  ResourceMark rm;
   // theoretical string size limit for decimal int, but the following loop will end much sooner due to
   // OS command-line size limit.
   const int max_digits = 10;
@@ -723,7 +729,7 @@ const char* Modules::get_numbered_property_as_sorted_string(const char* property
     }
   }
 
-  return (st.size() > 0) ? os::strdup(st.as_string()) : nullptr;  // Example: "java.base,java.compiler"
+  return (st.size() > 0) ? st.as_string() : nullptr;  // Example: "java.base,java.compiler"
 }
 
 void Modules::define_archived_modules(Handle h_platform_loader, Handle h_system_loader, TRAPS) {