PinnedArrayBuffer: copy a resizable ArrayBuffer whose bytes are read after the call

[robobun]

Problem

• A PinnedArrayBuffer borrow read after JS runs again crashes when a resizable ArrayBuffer shrinks in between: Bun.zstdCompress (panic: Segmentation fault), fs.promises.stat with a Buffer path (SEGV in PathLike::slice_z_with_force_copy, src/runtime/node/types.rs:945), and a sync fs call whose option getter calls resize(0) on the path's buffer.
• Cause: a pin blocks a detach, not a shrink. ArrayBuffer::resize unmaps the trimmed pages, so the held (ptr, len) points at unmapped memory.

Fix

• Add PinnedArrayBuffer::copy_if_resizable and root_read_only (src/jsc/array_buffer.rs): a resizable non-shared buffer gets a copy of its current bytes, and the view points at the copy until the handle drops.
• Used where the bytes are read in user space after the call: StringOrBuffer::from_js_async (zstd), the PathLike funnel (both arms) and CompressionStreamCoder::AsyncInput::new. fs.write keeps the zero-copy borrow (write(2) returns EFAULT). fs.read and shell redirects write into the buffer and keep root.
• Correct because only a resizable non-shared buffer can unmap under the borrow: a fixed-length buffer cannot shrink and a growable SharedArrayBuffer only grows in place. Node copies a Buffer path at call time too.
• Verified: test/js/bun/util/zstd.test.ts (three tests), test/js/node/fs/fs.test.ts (two tests). Four of five fail on the unfixed build. Other suites in Notes.

Background

• PinnedArrayBuffer is the Rust handle for a borrowed JS buffer: pin stops a detach, root also GC-roots the value for a job that outlives the call.
• PathLike is a parsed path argument. Its Buffer arm holds a PinnedArrayBuffer read by the fs call, the pool thread, or a Blob store.
• JSC answers a shrink of a resizable ArrayBuffer with mprotect(PROT_NONE) on the trimmed tail, so a stale pointer faults.

Notes

Repro on main (834ad12):

for (let i = 0; i < 20; i++) {
  const ab = new ArrayBuffer(256 * 1024, { maxByteLength: 1 << 21 });
  new Uint8Array(ab).fill(0x41);
  const p = Bun.zstdCompress(new Uint8Array(ab));
  ab.resize(0);
  await p;
}

• Release: panic: Segmentation fault at address 0x26447780001. Debug: ASAN SEGV on unknown address in MEM_read64 (vendor/zstd/lib/common/mem.h:184) on thread T2. Bun.zstdDecompress with a compressed input crashes the same way in MEM_read32.
• The PathLike case: const p = fs.promises.stat(new Uint8Array(resizableAB)); resizableAB.resize(0); gives ASAN SEGV in PathLike::slice_z_with_force_copy on thread T3 (the path is copied into a path buffer on the pool thread).
• The sync case: fs.writeFileSync pins the path, then reads the flag getter, then copies the path into a path buffer (write_file_with_path_buffer, node_fs.rs:7170). A getter that calls resize(0) gives ASAN SEGV in slice_z_with_force_copy on the main thread. readFileSync with a DataView path and an encoding getter, and mkdirSync with a raw ArrayBuffer path and a recursive getter, crash the same way.
• The Bun.file case: the store keeps the pinned buffer (PathLike::thread_isolated_copy). .text() clones the stored path (PathLike::clone, node_path.rs:39, to_vec of the slice) on the JS thread and faults after a shrink. The sync-arm copy fixes it, but the test does not assert it: Bun.file(anyBuffer) with BUN_DESTRUCT_VM_ON_EXIT=1 (the ASAN lane) trips validateIsNotSweeping at exit, because the store's PinnedArrayBuffer drops during the shutdown sweep and unpin downcasts the cell there. That is on main for every Buffer path since node:fs: async calls with a Buffer path no longer keep the Buffer alive forever #40511 and is separate from this change.
• Out of scope: the shell's ArrayBuffer redirects (> ${buf}, < ${buf}, src/runtime/shell/Builtin.rs, Cmd.rs) still root and read or write the view in user space, so a resize(0) while the command runs is still unsafe there. A redirect target has to receive the output, so a copy is not the fix for that site.
• Why fs.write is not copied: its pool-side reader is write(2). The kernel returns EFAULT for an unmapped page, so the caller gets an error and the process does not crash. A copy at the funnel would run before offset and length are parsed, so a small write from a large resizable buffer would copy the whole view. Node documents that the buffer must not change until the callback runs.
• Why the copy lives inside PinnedArrayBuffer and not at the call sites: the PinnedBuffer and PathLike::Buffer variants drive argument dispatch and carry the JS value. A copy that keeps the variant, the pin and the root changes nothing for those readers. The first version of this PR copied at the zstd site only; the review found the same crash through PathLike.
• Why not copy every input: the pinned borrow is the zero-copy path for the common fixed-length Buffer. An empty resizable buffer is not copied either: it has nothing to read, and a later grow keeps the pointer valid.
• The copy is freed with the job: 2000 rounds of Bun.zstdCompress on a 256 KiB resizable input leave RSS flat on the debug build.
• crypto, zlib, zstd: copy resizable ArrayBuffer inputs before queuing to the threadpool #34751 reported the zstd crash together with the same shape in crypto.pbkdf2/crypto.scrypt and node:zlib. The KDFs are fixed by node:crypto: copy password and salt for async pbkdf2 and scrypt #40554 (they copy every input, because a caller may zeroize a secret after the call). node:zlib rejects a resizable input since Robustness pass across install, css, ffi, crypto, spawn, shell, and node compat #36165. crypto, zlib, zstd: copy resizable ArrayBuffer inputs before queuing to the threadpool #34751 was closed because it was built on the plumbing node:fs: async calls with a Buffer path no longer keep the Buffer alive forever #40511 replaced. node: snapshot resizable async StringOrBuffer inputs before worker handoff #31645 proposed a funnel-level copy on that older plumbing.
• Supersedes node:fs: snapshot path buffers backed by resizable ArrayBuffers for async ops #32189 and node:fs: snapshot resizable-ArrayBuffer-backed path buffers so an option getter cannot resize(0) through the borrow #35840, which made the same path copy on the plumbing node:fs: async calls with a Buffer path no longer keep the Buffer alive forever #40511 replaced. Their cases pass on this branch: a rename with a shrink right after the call, 256 queued renames of a missing source as Uint8Array, DataView and raw ArrayBuffer (all ENOENT), the sync writeFileSync/readFileSync/mkdirSync getter shapes, a growable SharedArrayBuffer path, and Bun.file(view).text() read twice.
• Other suites run: test/js/node/fs/fs.test.ts (562 pass), test/js/node/fs/promises.test.js, test/js/bun/shell/bunshell.test.ts, test/js/web/streams/compression.test.ts, test/js/node/zlib/zlib.test.js, test/js/node/crypto/pbkdf2.test.ts, test/js/node/crypto/scrypt.test.ts, test/js/bun/util/bun-file.test.ts, test/js/bun/util/bun-file-read.test.ts, test/js/web/fetch/blob.test.ts.

---

no test proof · iteration 4 · platform-specific test(s) that do not run on this machine, deferring to CI, which covers all platforms: test/js/node/fs/fs.test.ts

[coderabbitai]

Walkthrough

Changes

Asynchronous ArrayBuffer rooting

Layer / File(s)	Summary
Read-only rooting storage src/jsc/array_buffer.rs	PinnedArrayBuffer stores copied bytes for resizable, non-shared buffers. Read-only access uses the copy. Mutable access rejects copied instances, and defuse releases the copy.
Asynchronous consumer wiring src/runtime/node/types.rs, src/runtime/webcore/CompressionStreamCoder.rs	Asynchronous buffer and path handling uses read-only rooting. Copy failures return out-of-memory errors. AsyncInput documents pinned storage and owned copies.
Resizable-buffer regression coverage test/js/bun/util/zstd.test.ts, test/js/node/fs/fs.test.ts	Tests cover shrinking buffers during zstd and filesystem operations, plus growing SharedArrayBuffer compression.

Suggested reviewers: jarred-sumner, alii

Merge Risk: 🟠 High · up to da103

The resizable-buffer fix still misses asynchronous PBKDF2 and Scrypt inputs, so shrinking a buffer during processing can crash the process; merge should wait until those paths are protected. The associated test script also needs correction to validate the intended loading behavior.

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description check	✅ Passed	The description clearly explains the problem, fix, affected consumers, scope decisions, and verification results. It does not use the exact template headings, but it provides the required content and …
Title check	✅ Passed	The title clearly identifies the main change: copying resizable ArrayBuffer data when later reads require stable bytes.

Full details: Description check

Explanation

The description clearly explains the problem, fix, affected consumers, scope decisions, and verification results. It does not use the exact template headings, but it provides the required content and is mostly complete.

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[robobun]

Status: ready for review.

Reproduced on main (834ad12) with the script in the PR body: Bun.zstdCompress on a resizable ArrayBuffer followed by resize(0) gives panic: Segmentation fault on the release build and an ASAN SEGV in MEM_read64 on the debug build. The same borrow crashes fs.promises.stat with a Buffer path (SEGV in PathLike::slice_z_with_force_copy on the pool thread), fs.writeFileSync with an option getter that calls resize(0) on the path's buffer (the same SEGV on the main thread), and Bun.file(view).text() after a resize(0) (SEGV in PathLike::clone).

The fix lives in PinnedArrayBuffer (copy_if_resizable, root_read_only) and applies where the bytes are read in user space after the call: StringOrBuffer::from_js_async (zstd), the PathLike funnel (both arms, so the pool thread, a sync call after its option getters, and a Blob store all read the bytes captured at call time) and CompressionStreamCoder. fs.write keeps its zero-copy borrow (write(2) returns EFAULT for a shrunk source, which is an error and not a crash). The new tests in test/js/bun/util/zstd.test.ts (compress, decompress, growable SharedArrayBuffer) and test/js/node/fs/fs.test.ts (fs.promises.stat with a Buffer path; writeFileSync, readFileSync, mkdirSync with a getter that shrinks the path) pass with the change; four of the five fail on the unfixed build. The Bun.file case is fixed by the same copy but not asserted by a test: Bun.file(anyBuffer) under BUN_DESTRUCT_VM_ON_EXIT=1 trips a separate, pre-existing JSC assertion at exit (the store's PinnedArrayBuffer unpins during the shutdown sweep), which is recorded in the PR notes. fs.test.ts, promises.test.js, bunshell.test.ts, compression.test.ts, zlib.test.js, pbkdf2.test.ts, scrypt.test.ts, bun-file.test.ts, bun-file-read.test.ts and blob.test.ts also pass.

This is the zstd part of #34751, which was closed because it was built on the plumbing #40511 replaced. The pbkdf2 and scrypt part is #40554. It supersedes #32189 and #35840, which made the same path copy on the older plumbing. Their test cases pass on this branch.

CI on d160666 (build 106965): the diff is green. 178 of 181 jobs pass, and the new zstd and fs tests pass on every lane. The three red lanes are pre-existing on main and do not touch this code: test/bundler/transpiler/macro-test.test.ts (x64-asan, a LeakSanitizer report in node_fs_binding::create_binding), test/cli/run/require-cache.test.ts (Windows x64, an RSS threshold) and test/js/web/url/url.test.ts (darwin x64, TypeError: Invalid URL in the Unicode 16 IDNA test). All three are reported to main-break triage.

[robobun]

^{Updated 12:49 PM PT - Aug 27th, 2026}

❌ @robobun, your commit d160666 has 3 failures in Build #106965 (All Failures):

• test/js/web/url/url.test.ts - code 1: TypeError: Invalid URL on 🍎 any x64
• test/cli/run/require-cache.test.ts - code 1: error: Memory leak detected on 🪟 2019 x64
• test/bundler/transpiler/macro-test.test.ts - leak +1 more on 🐧 13 x64-asan

---

🧪   To try this PR locally:

bunx bun-pr 40641

That installs a local version of the PR into your bun-40641 executable, so you can run:

bun-40641 --bun

[claude]

LGTM — focused segfault fix that copies a resizable non-shared ArrayBuffer before handing it to the pool thread.

What was reviewed:

• The resizable && !shared gate and owned-copy path match the existing CompressionStreamCoder::AsyncInput::new pattern; growable SABs correctly stay on the borrow path.
• get_level (which can run user JS via coercion) runs before as_array_buffer/byte_slice, so the copy reads post-coercion bytes; allocation failure throws OOM via try_reserve_exact.
• Tests spawn subprocesses (unfixed build crashes), drain pipes concurrently, assert stderr before exitCode, and cover compress/decompress/SAB.

Extended reasoning...

Overview

This PR fixes a segfault in the async Bun.zstdCompress/Bun.zstdDecompress paths when the caller passes a resizable ArrayBuffer and shrinks it after dispatch but before the pool thread reads it. The fix adds ~20 lines to get_options_async in src/runtime/api/BunObject.rs: when the input is a resizable, non-shared ArrayBuffer, its bytes are eagerly copied into an owned Vec (with try_reserve_exact → throw_out_of_memory on failure and report_extra_memory) and returned as StringOrBuffer::owned_isolated. All other inputs (fixed-length buffers, strings, growable SharedArrayBuffers) fall through unchanged to the existing pinned-borrow path. Three subprocess tests are added to test/js/bun/util/zstd.test.ts.

Security risks

None identified. This is a crash/memory-safety fix, not a security-boundary change. The new path only copies user-provided bytes into an owned allocation; there is no parsing, no path handling, no auth/crypto surface. The allocation size is bounded by the caller's own buffer length, and OOM is handled by throwing rather than panicking.

Level of scrutiny

Moderate. The change touches a pool-thread memory-safety path, so I verified: (1) the resizable && !shared predicate exactly matches the established in-tree precedent at CompressionStreamCoder::AsyncInput::new (src/runtime/webcore/CompressionStreamCoder.rs:724); (2) get_level — which coerces a user-supplied level and can therefore run arbitrary JS — is called before as_array_buffer/byte_slice, so the copy reads bytes after any observable side effects; (3) as_array_buffer returns None for strings and non-buffer values, so those still reach from_js_async and its error message; (4) the owned Vec is wrapped via owned_isolated, which is the documented ThreadIsolated constructor for Rust-owned bytes, and is dropped with the job.

Other factors

The tests follow harness conventions closely: describe.concurrent for independent subprocess cases, bunExe()/bunEnv, await using on Bun.spawn, concurrent pipe draining, stderr asserted before exitCode, Buffer.alloc(n, fill) instead of .repeat(), and results compared against the sync API on a fixed-length copy (so the test asserts correctness, not just non-crash). No CODEOWNERS entry covers the changed paths. The bug hunt ran to a dry streak with no findings and no ruled-out candidates. The change is small, additive, and mirrors an existing pattern, so I'm comfortable approving.

[robobun]

Nothing to change from the review. CI on 2995c40: the diff is green. The two red lanes (macro-test.test.ts on x64-asan, url.test.ts on darwin x64) are pre-existing on main, do not touch this code, and are reported to triage. Details in the status comment above.

[coderabbitai]

Actionable comments posted: 1

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Inline comments:
In `@test/js/bun/util/zstd.test.ts`:
- Around line 688-698: Update runInChild to return both trimmed stdout and
exitCode instead of asserting the exit status internally; adjust each caller in
the affected tests to assert expected stdout first, then stderr, and finally
exitCode equals 0.

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• src/jsc/array_buffer.rs
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• test/js/node/fs/fs.test.ts

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[robobun]

Re-targeted after a self-review. The first version copied the input at the zstd call site only. The same borrow through PinnedArrayBuffer::root crashes fs.promises.stat with a Buffer path backed by a resizable ArrayBuffer (SEGV in PathLike::slice_z_with_force_copy on the pool thread) and makes fs.write return EFAULT. So the copy now lives in a PinnedArrayBuffer::root_read_only constructor in src/jsc/array_buffer.rs, and the three read-only root callers use it: StringOrBuffer::buffer_from_js(Flavor::Async), the PathLike async arm and CompressionStreamCoder::AsyncInput::new (which drops its own copy of the rule). The zstd site is unchanged. Tests for fs.write and fs.promises.stat are added to test/js/node/fs/fs.test.ts.

Review feedback so far is folded in: one-line doc comments (47c7fb7) and stdout asserted before the exit code in the zstd child-process helper (7322521).

[robobun]

5152111 narrows the copy to the jobs that read the bytes in user space. StringOrBuffer::buffer_from_js(Flavor::Async) is back to the zero-copy borrow, so fs.write and fs.writeFile do not copy a resizable view before offset and length are parsed (a small write from a large resizable buffer would have copied the whole view); their reader is write(2), which returns EFAULT for a shrunk source. The copy now runs in StringOrBuffer::from_js_async (zstd) through the new PinnedArrayBuffer::copy_if_resizable, and in the PathLike async arm and CompressionStreamCoder through root_read_only. The fs.write test is gone with it; the fs.promises.stat test runs 20 rounds in a child so the unfixed build faults on one of them. The PR body describes this shape.

[claude]

Both earlier findings are addressed: buffer_from_js is back to plain root so async fs.write stays zero-copy (the copy now lives only in StringOrBuffer::from_js_async and the PathLike async arm), and the racy fs.write test was replaced with a 20-round child-process fs.promises.stat case that mirrors the zstd tests. No new issues found. Since this repoints PinnedArrayBuffer.buffer.ptr at an owned Vec and threads that through pool-side readers, a human pass on the memory-safety plumbing is still worthwhile.

What was reviewed:

• copy_if_resizable: try_reserve_exact before extend_from_slice, report_extra_memory, ptr repointed only after self.copy owns the Vec, defuse clears it — no leak or dangling on the new field.
• Confirmed fs.write's arg parser still goes through buffer_from_js → root, not the copying path; from_js_async callers (zstd in BunObject.rs, JSTranspiler) read the whole slice in user space so a full-view copy is correct there.
• slice_mut debug-asserts no read-only copy; CompressionStreamCoder's inline resizable check is now the shared helper with equivalent semantics (still returns the pinned (ptr, len), which now points at the owned copy).

Extended reasoning...

Overview

The PR adds copy: Option<Vec<u8>> to PinnedArrayBuffer plus copy_if_resizable() / root_read_only(), so a work-pool job that reads a resizable non-shared ArrayBuffer in user space snapshots the bytes at call time instead of faulting when JS calls resize(0) and JSC unmaps the tail. Callers updated: StringOrBuffer::from_js_async (zstd, transpiler), the PathLike async Buffer arm, and CompressionStreamCoder::AsyncInput::new (which drops its own inline copy of the same rule). Four subprocess tests added across zstd.test.ts and fs.test.ts.

Security risks

No auth/crypto/permissions surface. The risk class is memory safety across the JS/pool-thread boundary: the change repoints buffer.ptr at a heap-owned Vec and hands (ptr, len) to another thread. The Vec is stored in self.copy before ptr is taken, lives as long as the PinnedArrayBuffer (which is rooted for the job's lifetime), and is dropped by defuse() / Drop. Allocation failure returns false and callers throw OOM rather than panicking. No new unsafe blocks; existing SAFETY comments were tightened to stop claiming the pin holds "the backing store" and now say "bytes the paired PinnedArrayBuffer keeps valid", which is accurate for both the borrowed and copied cases.

Level of scrutiny

High. This is shared native plumbing (src/jsc/array_buffer.rs, src/runtime/node/types.rs) on a cross-thread memory-safety path where a mistake is a UAF or a segfault. REVIEW.md flags this exact class ("Never let a pointer or slice outlive the memory it points into", "A Strong ref does not prevent ArrayBuffer detach"). Not a candidate for bot approval.

Other factors

Since my last review (commit 7322521), commit 5152111 reverted the funnel-level root_read_only in buffer_from_js back to root — so args::Write::from_js (node_fs.rs) no longer copies the whole resizable view before offset/length are parsed, addressing the whole-buffer-copy / OOM regression I flagged. The racy single-shot fs.write test was deleted and replaced with a 20-iteration child-process fs.promises.stat test that follows the same shape as the zstd tests (loop, resize(0), assert output, assert stderr empty, assert exit 0 last). Both prior inline threads are now addressed by code, not just self-resolved. No outstanding third-party CHANGES_REQUESTED reviews in the timeline.

[robobun]

Nothing to change from this review. The PR is ready for a maintainer pass on the PinnedArrayBuffer change: 5152111 is the final shape, CI on it is green except for the two pre-existing main breaks listed in the status comment, and all review threads are resolved.

[robobun]

da103d4 extends the copy to the whole PathLike funnel. Two shapes still crashed on 5152111 because only the async arm copied:

• A sync call reads the path after the option getters ran, and a getter can shrink the buffer: fs.writeFileSync(view, data, { get flag() { ab.resize(0); return "w"; } }) faulted in slice_z_with_force_copy on the main thread. readFileSync with a DataView path and mkdirSync with a raw ArrayBuffer path behave the same.
• Bun.file(view) keeps the pinned buffer in its store. ab.resize(0) followed by .text() faulted in PathLike::clone.

copy_if_resizable now runs for both arms in PathLike::from_js_with_allocator, so every consumer of a PathLike::Buffer reads the bytes captured at call time. One test covers the three sync shapes and Bun.file in a child process. It fails on 5152111 and passes here.

This supersedes #32189 and #35840, which made the same copy on the plumbing #40511 replaced. Their test cases pass on this branch (details in the PR body).

[coderabbitai]

Actionable comments posted: 1

Caution

Some comments are outside the diff and can’t be posted inline due to platform limitations.

⚠️ Outside diff range comments (1)

src/runtime/node/types.rs (1)

354-355: 🩺 Stability & Availability | 🟠 Major | 🏗️ Heavy lift

Copy resizable buffers in every asynchronous conversion path.

PBKDF2::from_js_async and Scrypt::from_js_async wrap Flavor::Async results directly and bypass StringOrBuffer::from_js_async's copy_if_resizable. Their work-pool jobs read PinnedBuffer::slice(). If a resizable non-shared ArrayBuffer shrinks before the read, the pages can be unmapped and the native operation can fault.

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In `@src/runtime/node/types.rs` around lines 354 - 355, Update
PBKDF2::from_js_async and Scrypt::from_js_async to copy resizable non-shared
ArrayBuffers before their work-pool jobs read PinnedBuffer::slice(), matching
StringOrBuffer::from_js_async’s copy_if_resizable behavior; do not wrap
Flavor::Async results directly when this safety step is required.

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minimal, and validate.

Inline comments:
In `@test/js/node/fs/fs.test.ts`:
- Around line 6761-6762: Replace the dynamic require calls for the node:fs and
node:path modules in the child script with static imports, while preserving the
existing module bindings and test behavior.

---

Outside diff comments:
In `@src/runtime/node/types.rs`:
- Around line 354-355: Update PBKDF2::from_js_async and Scrypt::from_js_async to
copy resizable non-shared ArrayBuffers before their work-pool jobs read
PinnedBuffer::slice(), matching StringOrBuffer::from_js_async’s
copy_if_resizable behavior; do not wrap Flavor::Async results directly when this
safety step is required.

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[robobun]

d6f6d2e folds in the two inline comments: a one-line comment on the PathLike copy and static imports in the child scripts.

On the out-of-diff remark about PBKDF2::from_js_async and Scrypt::from_js_async: those two are #40554. It replaces their async parse with a copy of every input after argument coercion, not only of resizable buffers, because a caller may zeroize a secret right after the call and the key must still come from the bytes passed. A resizable-only copy here would not give that, so the KDF slice stays in that PR. The two changes touch different lines and are independent: this PR leaves the KDF paths as they are on main, and #40554 no longer routes them through buffer_from_js(Flavor::Async) at all. Either merge order is safe.

[robobun]

d160666 drops the Bun.file case from the fs test. On the ASAN lane the runner sets BUN_DESTRUCT_VM_ON_EXIT=1, and with that flag Bun.file(anyBuffer) trips ASSERTION FAILED: vm().currentThreadIsHoldingAPILock() => vm().heap.mutatorState() != MutatorState::Sweeping at exit: the Blob store's PinnedArrayBuffer drops during the shutdown sweep and unpin downcasts the cell there. That happens for a fixed-length Buffer.from(path) too, with or without this change, so it is a separate bug on main since #40511. The resize fix for Bun.file stays in (the sync-arm copy), and the writeFileSync, readFileSync and mkdirSync cases exercise the same arm. Repro for the separate bug, with the debug build:

// BUN_DESTRUCT_VM_ON_EXIT=1 bun-debug script.js
const file = Bun.file(Buffer.from("/tmp/small.txt"));
console.log(await file.text());

The shell ArrayBuffer redirects are now named as out of scope in the PR body, with the reason.

[claude]

Code review found no issues

No high-confidence issues detected in this change.

[robobun]

Nothing to change from this review. d160666 is the final shape and is ready for a maintainer pass. CI on it is green apart from the three pre-existing main breaks listed in the status comment, and all review threads are resolved.