René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"ffi: Detached ArrayBuffers and views are silently converted to null FFI pointers","articleBody":"### Version\n\nmain\n\n### Platform\n\n```text\nmacOS 26.6.0\n```\n\n### Subsystem\n\nffi\n\n### What steps will reproduce the bug?\n\n`repro.c`\n```c\n#include \u003cstdint.h>\n\nuint64_t pointer_to_usize(void* ptr) {\n  return (uint64_t)(uintptr_t)ptr;\n}\n```\n\n`repro.js`\n```js\nimport { resolve } from 'node:path';\nimport { dlopen, suffix, getRawPointer } from 'node:ffi';\n\nconst { lib, functions } = dlopen(\n  resolve(`repro.${suffix}`),\n  {\n    pointer_to_usize: {\n      arguments: ['pointer'],\n      return: 'u64',\n    },\n  },\n);\n\nconst arrayBuffer = new ArrayBuffer(8);\nconst typedArray = new Uint8Array(arrayBuffer);\nconst dataView = new DataView(arrayBuffer);\n\nstructuredClone(arrayBuffer, { transfer: [arrayBuffer] });\n\nfunction show(label, operation) {\n  try {\n    console.log(label, operation());\n  } catch (error) {\n    console.log(label, error.code);\n  }\n}\n\ntry {\n  for (const [name, value] of [\n    ['ArrayBuffer', arrayBuffer],\n    ['Uint8Array', typedArray],\n    ['DataView', dataView],\n  ]) {\n    show(`getRawPointer(${name})`, () => getRawPointer(value));\n    show(`pointer_to_usize(${name})`, () =>\n      functions.pointer_to_usize(value));\n  }\n} finally {\n  lib.close();\n}\n```\n\nCommands to run\n```sh\n$ cc -dynamiclib -o repro.dylib repro.c\n$ node --no-warnings --experimental-ffi repro.js\n```\n\n### How often does it reproduce? Is there a required condition?\n\nAlways\n\n### What is the expected behavior? Why is that the expected behavior?\n\nEach operation should throw `ERR_INVALID_ARG_VALUE`, consistent with `ExportBytes()` rejecting detached buffers and views.\n\n### What do you see instead?\n\n```console\ngetRawPointer(ArrayBuffer) 0n\npointer_to_usize(ArrayBuffer) 0n\ngetRawPointer(Uint8Array) 0n\npointer_to_usize(Uint8Array) 0n\ngetRawPointer(DataView) 0n\npointer_to_usize(DataView) 0n\n```\n\nAll six operations return `0n`, silently treating detached memory as a null pointer.\n\n### Additional information\n\n_No response_","author":{"url":"https://github.com/trivikr","@type":"Person","name":"trivikr"},"datePublished":"2026-08-06T14:43:01Z","url":"https://github.com/nodejs/node/issues/65082"}