fix(ext/node): fix Buffer.concat, expose internal/buffer, implement markAsUntransferable#32760
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bartlomieju merged 5 commits intomainfrom Mar 17, 2026
Merged
fix(ext/node): fix Buffer.concat, expose internal/buffer, implement markAsUntransferable#32760bartlomieju merged 5 commits intomainfrom
bartlomieju merged 5 commits intomainfrom
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…length Use TypedArrayPrototypeGetByteLength instead of .length in Buffer.concat() to prevent spoofed length getters from causing uninitialized memory exposure. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Register internal/buffer as a requireable internal module and export utf8Write from it, enabling test-buffer-write-fast.js. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
…ansferable Add op_mark_as_untransferable using V8's set_detach_key to make ArrayBuffers truly non-transferable (both via postMessage and ArrayBuffer.prototype.transfer()). Apply it to the Buffer pool and implement worker_threads.markAsUntransferable(). Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
kajukitli
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Mar 16, 2026
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Reviewed with full repo context. Initial findings didn't hold up on closer inspection. Looks good.
nathanwhit
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Mar 17, 2026
ext/node/ops/buffer.rs
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| scope: &mut v8::PinScope<'_, '_>, | ||
| ab: v8::Local<v8::ArrayBuffer>, | ||
| ) { | ||
| let key = v8::String::new(scope, "untransferable").unwrap(); |
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could use v8_static_strings here
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Summary
Fixes 3 Buffer compat tests from #32706 and fixes #31824.
TypedArrayPrototypeGetByteLengthinstead of.lengthto prevent spoofed length getters from causing uninitialized memory exposureutf8Writeset_detach_keyAPI. Applied to the Buffer pool soArrayBuffer.prototype.transfer()throwsTypeErrorinstead of detaching the shared pool. This prevents the bug where transferring a Buffer's backing store would break all subsequentBuffer.from()calls (Bufferis totally broken in the presence of transferable buffers #31824)Enabled tests
test-buffer-concat.jstest-buffer-write-fast.jstest-buffer-pool-untransferable.jsCloses #31824
Test plan
./x test-compatBufferis totally broken in the presence of transferable buffers #31824 repro no longer reproduces🤖 Generated with Claude Code