ffi: validate DynamicLibrary getter receivers

Bind the path, symbols, and functions getter templates to the
DynamicLibrary constructor signature. This causes V8 to reject
incompatible receivers before invoking the native callbacks,
preventing them from crashing the process.

Signed-off-by: Kamat, Trivikram <16024985+trivikr@users.noreply.github.com>
Assisted-by: codex:gpt-5.6-sol

Author: trivikr

src/node_ffi.cc

@@ -35,6 +35,7 @@ using v8::MaybeLocal;
 using v8::Object;
 using v8::PropertyAttribute;
 using v8::ReadOnly;
+using v8::Signature;
 using v8::String;
 using v8::TryCatch;
 using v8::Value;
@@ -1238,16 +1239,23 @@ Local<FunctionTemplate> DynamicLibrary::GetConstructorTemplate(
     tmpl = NewFunctionTemplate(isolate, DynamicLibrary::New);
     tmpl->InstanceTemplate()->SetInternalFieldCount(
         DynamicLibrary::kInternalFieldCount);
+    Local<Signature> signature = Signature::New(isolate, tmpl);
 
     tmpl->InstanceTemplate()->SetAccessorProperty(
         env->path_string(),
-        FunctionTemplate::New(env->isolate(), DynamicLibrary::GetPath),
+        FunctionTemplate::New(isolate,
+                              DynamicLibrary::GetPath,
+                              Local<Value>(),
+                              signature),
         Local<FunctionTemplate>(),
         attributes);
 
     tmpl->InstanceTemplate()->SetAccessorProperty(
         FIXED_ONE_BYTE_STRING(isolate, "symbols"),
-        FunctionTemplate::New(env->isolate(), DynamicLibrary::GetSymbols),
+        FunctionTemplate::New(isolate,
+                              DynamicLibrary::GetSymbols,
+                              Local<Value>(),
+                              signature),
         Local<FunctionTemplate>(),
         attributes);
 
@@ -1257,7 +1265,10 @@ Local<FunctionTemplate> DynamicLibrary::GetConstructorTemplate(
     // reason.
     tmpl->PrototypeTemplate()->SetAccessorProperty(
         FIXED_ONE_BYTE_STRING(isolate, "functions"),
-        FunctionTemplate::New(env->isolate(), DynamicLibrary::GetFunctions),
+        FunctionTemplate::New(isolate,
+                              DynamicLibrary::GetFunctions,
+                              Local<Value>(),
+                              signature),
         Local<FunctionTemplate>(),
         static_cast<PropertyAttribute>(ReadOnly));
 

test/ffi/test-ffi-dynamic-library.js

@@ -124,6 +124,24 @@ test('DynamicLibrary exposes functions and symbols', () => {
   }
 });
 
+test('DynamicLibrary getters reject incompatible receivers', () => {
+  const lib = new ffi.DynamicLibrary(libraryPath);
+
+  try {
+    const invalidGets = [
+      () => Reflect.get(lib, 'path', {}),
+      () => Reflect.get(lib, 'symbols', {}),
+      () => Reflect.get(ffi.DynamicLibrary.prototype, 'functions', {}),
+    ];
+
+    for (const invalidGet of invalidGets) {
+      assert.throws(invalidGet, TypeError);
+    }
+  } finally {
+    lib.close();
+  }
+});
+
 test('DynamicLibrary evaluates function signatures once', () => {
   function makeChangingSignature() {
     const reads = { arguments: 0, return: 0 };