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A Response body stream that errors after the status and some bytes went out reaches RequestContext::force_close(). For HTTP/1 that closes the socket without the terminating chunk. For HTTP/3 it called us_quic_stream_close(), which queues a FIN, and in HTTP/3 a FIN marks a complete message. The client received the truncated body as a complete 200 response. uws_h3_res_force_close now sends RESET_STREAM(H3_INTERNAL_ERROR) through us_quic_stream_reset, which takes the HTTP/3 error code as a parameter. The H3 fetch client's stream-close callback no longer treats a stream that closed without a FIN as the end of the body: it fails the request with HTTP3StreamReset when the peer reset the stream and with ConnectionClosed when the connection went away under it.
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Status: reproduced and fixed, ready for a maintainer. CI is green except for Reproduced with a debug build of main: a The self-review also found that the client re-sent any request whose stream was reset before the headers. It now re-sends only on |
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No actionable comments were generated in the recent review. 🎉 ℹ️ Recent review info⚙️ Run configurationConfiguration used: Path: .coderabbit.yaml Review profile: ASSERTIVE Plan: Pro Run ID: 📒 Files selected for processing (5)
Included review availability: Your plan provides up to 5 included reviews per hour; 0 remain after this review. WalkthroughChangesHTTP/3 streams now carry explicit reset error codes and peer-reset state. Client closure handling distinguishes retries, peer resets, aborted clients, and connection closures. Server failures send HTTP/3 stream reset handling
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Actionable comments posted: 2
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In `@test/js/bun/http/serve-http3.test.ts`:
- Around line 1469-1475: Replace the fixed Bun.sleep(10) timing in the pull
callback of serve-http3.test.ts at lines 1469-1475 with an awaited write/flush
signal before enqueuing the next chunk or calling c.error. Apply the same change
in fetch-http3-client.test.ts at lines 700-705: in onheaders, await the writer’s
flush or drain promise before calling end(...). Do not use sleep or setTimeout;
synchronize on the actual I/O event.
- Around line 1536-1544: Update h3ReadBody and the “stream ends with
RESET_STREAM” test to capture the structured QUIC error code and reset
errorCode, then assert code equals ERR_QUIC_STREAM_RESET and errorCode equals
258 instead of matching the full end message text. Preserve the existing status
assertion and response behavior.
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packages/bun-usockets/src/quic.cpackages/bun-usockets/src/quic.hsrc/http/h3_client/ClientSession.rssrc/http/h3_client/callbacks.rssrc/uws_sys/libuwsockets_h3.cppsrc/uws_sys/quic.rssrc/uws_sys/quic/Stream.rstest/js/bun/http/serve-http3.test.tstest/js/web/fetch/fetch-http3-client.test.ts
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Updated 12:50 AM PT - Aug 27th, 2026
❌ @robobun, your commit 4aaf797 has 1 failures in
🧪 To try this PR locally: bunx bun-pr 40598That installs a local version of the PR into your bun-40598 --bun |
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I reviewed this PR and didn't find any bugs. Because it changes wire-level HTTP/3 stream-close semantics on both the server and client sides and adjusts an FFI signature across C/C++/Rust, a human look would still be worthwhile.
What was reviewed:
- FFI signature change to
us_quic_stream_reset— all call sites (RustStream::reset, C++uws_h3_res_force_close) updated in lockstep;H3ErrorCode#[repr(u64)]matches the Cuint64_t. - New
peer_resetfield — zero-initialized viaus_callocat stream allocation, so no uninitialized read. on_stream_closedcontrol flow —qstreamis nulled beforefail()runs, soStream::abort()is a no-op and the freed lsquic stream is not touched; the pre-headers path still routes throughdeliverfor the stale-session retry.- Tests — extend existing files, use
port: 0and localnode:quicservers; theBun.sleep(10)calls yield to the event loop for lsquic packetization (commented) rather than waiting on a condition.
Extended reasoning...
Overview
This PR fixes a correctness bug where Bun.serve over HTTP/3 sent FIN instead of RESET_STREAM when a response body stream errored mid-transmission, causing clients to receive truncated bodies as complete messages. It also fixes the mirror bug in the HTTP/3 fetch client, which treated every post-headers stream close as a clean end-of-body. The change spans packages/bun-usockets/src/quic.{c,h} (new peer_reset flag, us_quic_stream_reset gains an error-code parameter, new us_quic_stream_peer_reset accessor), src/uws_sys/libuwsockets_h3.cpp (force_close now resets instead of closes), src/uws_sys/quic/Stream.rs (Rust FFI bindings + H3ErrorCode enum), and src/http/h3_client/{ClientSession.rs,callbacks.rs} (new on_stream_closed that distinguishes FIN from RESET_STREAM/CONNECTION_CLOSE). Four new tests cover both server-emits-reset and client-interprets-reset paths.
Security risks
None identified. This is an RFC 9114 correctness fix — sending RESET_STREAM instead of FIN when a body fails is the spec-mandated behavior. The change does not touch auth, crypto, TLS, or input parsing. If anything, it improves security posture: previously a truncated body could be silently accepted as complete, which is a data-integrity concern.
Level of scrutiny
Moderate-to-high. The change is focused and well-motivated with clear RFC citations, and mirrors the existing HTTP/2 RST_STREAM handling. However, it modifies protocol-level stream lifecycle behavior in both the server and client HTTP/3 stacks, changes an FFI function signature across three languages, and adds new control flow in the h3 client's stream-close callback (which runs inside lsquic's process_conns and interacts with pointer-provenance-sensitive session/stream lifetime code). These are exactly the kind of changes where a subtle ordering or lifetime issue could produce a UAF or a hung request, so a maintainer familiar with the h3 client internals should confirm the reasoning about "a FIN always detaches inside deliver, so an attached stream at close never got one."
Other factors
The bug hunt ran to dry_streak with no findings. I verified: the new struct field is zero-initialized (us_calloc); all us_quic_stream_reset callers were updated; on_stream_closed nulls qstream before calling fail() so the dying lsquic stream is not touched via abort(); the Aborted signal check preserves the ordering deliver had. The tests are well-constructed — they extend existing test files, use local node:quic servers (no external network), assert composite objects with .toEqual, and include both a fetch() end-to-end assertion and a wire-level assertion that RESET_STREAM(0x102) is what goes out. The Bun.sleep(10) calls are under the 50ms REVIEW.md threshold, are commented as event-loop yields for lsquic packetization, and are not waiting on a condition. No CODEOWNERS entries cover the changed paths. The change is not simple/mechanical enough for auto-approval given it alters transport-layer error semantics.
…leep The fixture servers now fail the body only after the client requests /release, which it does once it holds the status and the first chunk. The node:quic reader asserts the RESET_STREAM error code through the stream's closed promise instead of the error message text.
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Review follow-up, pushed in c79e217 and 405ec97:
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…REQUEST_REJECTED The stream-close callback now carries the peer's RESET_STREAM error code. Before the response headers, the client re-sends the request once only when the connection went away under it or the code is H3_REQUEST_REJECTED (0x10B), the one code that promises the server did no application processing. Any other reset fails the request with HTTP3StreamReset, as the h2 client retries only REFUSED_STREAM. The HTTP/3 error codes now live in one place, the Rust H3ErrorCode enum; uws_h3_res_force_close takes the code from its Rust caller.
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Self-review follow-up, pushed in 1256a9c and 4aaf797:
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Ordering note: the pre-first-byte framing change is now #40648 (stacked on #40596), and it keeps the HTTP/3 path on the normal end when no body byte went out, for the reason described here (a FIN before HEADERS makes the client re-send the request). So this PR no longer has to land before it. Once this PR is in, the |
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…#40596) ### Problem - A `Bun.serve` Response whose body stream fails before any body byte is written is delivered to the client as a complete message: the Response's status and headers, `Transfer-Encoding: chunked`, an empty body and a clean `0\r\n\r\n`. `curl` exits 0. A proxied upstream body that dies before its first chunk is forwarded the same way, and nothing is reported. Only a failure after the first body byte closed the connection without the terminator (#32842). - Cause: three sites in `src/runtime/server/RequestContext.rs` handle a body failure after the status line is committed (`handle_reject` for a direct stream's synchronous `pull()` throw, `handle_reject_stream` for a JS stream, `end_chunk` for a native byte stream). Each force-closed only when `is_http_write_called()` and otherwise called `end_stream()`, which writes the terminating chunk. ### Fix - The three sites share a new `close_incomplete_stream`: while the response is still pending, `force_close()` the connection, whether or not body bytes went out first. Once the sink has already ended the response, `end_stream()` only releases the context, as before. - Correct because a chunked message is complete only with its terminator (RFC 9112 section 7). An empty chunked body with a terminator is as complete as a truncated one. Closing without it is the only way HTTP/1.1 can signal an incomplete message. When the status is still in the cork buffer, the close discards it and the client sees an empty reply, the same as Node's `res.destroy()` before the headers flush. - `end_chunk` (HTMLRewriter output, a proxied `fetch()` body) no longer drops the producer's error: it reports it in both modes through the shared `report_committed_body_error`, which also gives native bodies the bake dev server error page that JS streams already had. This carries the remaining parts of #39442, closed in favor of this PR. - Verified: `test/js/bun/http/serve-stream-body-error.test.ts` (JS stream variants, pending error after the headers, HTMLRewriter and proxied fetch bodies in both modes, two dev server rows; 17 of 26 fail on stock bun). Also `serve.test.ts`, `serve-direct-readable-stream.test.ts`, `async-iterator-stream.test.ts`, `serve-http3.test.ts`, `serve-error-handler-stream.test.ts`, `serve-stream-reject-flush-leak.test.ts`, `text-encoder-stream.test.ts`, `html-rewriter.test.js`. ### Background - `RequestContext` is the per-request state of `Bun.serve`. `do_render_stream` writes the Response's status and headers into the corked uWS response before it attaches the body stream, so by the time a body error arrives `has_written_status()` is already true and `error()` cannot supply a replacement. That contract is unchanged here: `error()` is still not called once the status is committed. - uWS corks a socket while a request handler runs: writes go to a per-socket buffer that is flushed when the handler returns. `force_close()` closes the socket directly and drops that buffer, so a synchronous failure leaves nothing on the wire. An asynchronous failure arrives after the flush, so the client gets the headers and then a reset. - Behavior change: the tests that pinned the old contract ("throw on pull renders headers", "async generator ... continues to send the headers", the pre-first-byte variants in `serve-stream-body-error.test.ts`) now expect the connection to close without a complete response. <details><summary>Notes</summary> Wire before the fix, for `new Response(new ReadableStream({ start(c) { c.enqueue(chunk); c.error(new Error("boom")); } }))`: ``` HTTP/1.1 200 OK Content-Type: text/plain;charset=utf-8 Date: ... Transfer-Encoding: chunked 0 ``` After: the connection closes with 0 bytes sent (the status was still corked). For a stream whose first `pull()` is asynchronous, the headers were already flushed, so the client gets `HTTP/1.1 200 OK` plus headers and then a connection reset with no terminating chunk. Both are incomplete messages. The error reaches stderr through the existing reporters; the production-mode asynchronous JS path stays quiet, as today. The forced close sends a RST, and a RST discards data the peer has not read yet (always on Windows). The tests that expect the status line on the wire before the failure therefore trigger the failure from the client's data handler, once the status line has arrived. uWS terminates the header block only with the first body byte, so those tests wait for the status line, not for a blank line. Dev server exception: under a bake dev server (`development: true` plus an HTML route), a body that fails after the status is committed gets the dev error page appended and the response ends normally, so the browser shows the error after what was already streamed. JS streams always did this; native bodies now take the same branch. Probed sources, all now closed incomplete: `controller.error` in `start`, synchronous and asynchronous `pull()` throw, async generator throw, `Readable.toWeb` of an erroring node stream, a throwing `TransformStream`, `DecompressionStream` on bad bytes, a `type: "direct"` stream that throws, an HTMLRewriter handler that throws or rejects after the first byte, a proxied upstream fetch body reset before and after its first chunk. `Bun.file()` on a missing path already reaches `error()` and answers 500 (unchanged). A user `Content-Length` header on a stream Response is ignored in favor of chunked framing, so it does not change the outcome. Related PRs in this area: #35229 deferred the status line until the first body byte so that `error()` can answer a pre-first-byte failure with a 500 (a larger change to `do_render_stream` and the sink), closed in favor of this PR; that design remains a possible follow-up. #38003 touches the same sites for the stored-ByteStream-error case. This PR only enforces the framing invariant; it does not decide whether `error()` should be reachable for these failures. HTTP/3 is not fixed by this change: `uws_h3_res_force_close` closes the QUIC stream with a FIN, which is a complete message in HTTP/3. That is tracked separately in #40598. </details> <!-- robobun:evidence:begin --> --- **no test proof** · iteration 5 · platform-specific test(s) that do not run on this machine, deferring to CI, which covers all platforms: test/js/bun/http/serve.test.ts <!-- robobun:evidence:end -->
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make the structs smaller this is big
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A note from closing #40648. Since #40596 (ec70edb), The Notes above say the "error before the first chunk" case still takes |
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### Problem - Over HTTP/3, an aborted `fetch()` upload ends with FIN, not RESET_STREAM. The server takes the truncated body for a complete request: `await req.text()` resolves `"hello "`. HTTP/1.1 reports an abort. - With a declared `content-length`, the server's lsquic answers the short FIN with CONNECTION_CLOSE (`H3_MESSAGE_ERROR`). The next stream upload on the pooled session rejects with `TypeError: HTTP3StreamReset fetching ...` (20 to 26 of 30 rounds). - Cause: `ClientSession::fail` (`src/http/h3_client/ClientSession.rs:206`) calls `Stream::abort()` (`lsquic_stream_close`) before `detach()`. The close queues FIN and sets `STREAM_U_WRITE_DONE`, so the `reset()` in `detach()` sends nothing. ### Fix - `fail()` and `retry_or_fail()` call `detach_with(stream, true)`, the teardown behind `detach()`. They no longer close the lsquic stream first. An unfinished send half ends with `RESET_STREAM(H3_REQUEST_CANCELLED)`. A finished one closes as before. `Stream::abort()` is gone. - `us_quic_stream_reset` always ends with `lsquic_stream_close`. `lsquic_stream_maybe_reset` shuts only the read half when no RESET_STREAM is due. - Correct per RFC 9114 section 4.1.1: RESET_STREAM cancels a request. The HTTP/2 client sends RST_STREAM(CANCEL) here. - Verified: `test/js/web/fetch/fetch-http3-client.test.ts` (2 new tests, the released binary fails both) and five other HTTP/3 suites. Self-reviewed: 10 concerns, 7 addressed (Notes). ### Background - The fetch HTTP/3 client pools one `ClientSession` (one QUIC connection) per origin. Each request is a `Stream` bound to one lsquic stream. - FIN ends the send half of a QUIC stream: "this is the whole message". RESET_STREAM aborts it. - lsquic checks a declared `content-length` when it reads the FIN (`verify_cl_on_fin`). A mismatch closes the whole connection. - `fail()` is the client's error path (user abort, malformed response, decode error). `detach()` tears down every request. <details><summary>Notes</summary> **lsquic calls.** `lsquic_stream_close` runs `stream_shutdown_write`. That sets `STREAM_U_WRITE_DONE` and queues FIN when the headers are out. `lsquic_stream_maybe_reset` sends RESET_STREAM only when none of `STREAM_RST_SENT`, `STREAM_FIN_SENT`, `STREAM_U_WRITE_DONE`, `SMQF_SEND_RST` is set. With `do_close`, its other branch runs `stream_shutdown_read` only. That does not set `STREAM_U_WRITE_DONE`, does not make the connection tickable, and does not call `maybe_schedule_call_on_close`. So `us_quic_stream_reset` now calls `lsquic_stream_maybe_reset(.., 0)` and then `lsquic_stream_close`. In the reset branch this equals the old `do_close=1` (`stream_reset` ends in `lsquic_stream_close`). In the other branch it is a full close. Neither call runs a stream callback synchronously. **Shape of the Rust change.** `detach()` is now a wrapper for `detach_with(stream, false)`. `detach_with` holds the old body of `detach()`, and its reset condition is `abort || !request_body_done`. `fail()` and `retry_or_fail()` call `detach_with(stream, true)` where they called `Stream::abort()` and then `detach()`. One function unbinds, resets and frees, so no caller can leave an unbound entry in `pending` (which `on_stream_open` would bind to a new lsquic stream), and lsquic sees one close per stream. **Wire, before** (`BUN_DEBUG_lsquic=1`): ``` stream: lsquic_stream_close() called stream: have to create a separate STREAM frame with FIN flag in it conn: generated 4-byte STOP_SENDING frame (stream id: 4, error code: 256) conn: abort error: is_app: 1; error code: 270; error str: number of bytes in DATA frames of stream 4 is 6, while content-length specified of 50 [h3_client] stream_close status=0 delivered=false [h3_client] conn_close status=8 '' ``` **Wire, after:** ``` stream: reset, error code 268 event: generated RESET_STREAM: stream 4; offset 75; error code 268 event: RX RST_STREAM frame: error code 268, stream 4, offset: 75 ``` The next upload runs on the same session. **Probes by hand (debug ASAN build).** - A Buffer body aborted while the handler waits. Before (64 MB): the handler saw `complete 40702` and `complete 103029` (bytes) in 2 of 3 rounds. After (16 MB): `aborted AbortError` in 3 of 3 rounds. String and Buffer bodies take the same `abort()` path. - A server that responds without reading the body (Bun.serve sends STOP_SENDING), with and without an abort during the response: same result before and after. Each request stream gets its lsquic `on_close` on both endpoints at once, not at connection teardown. `fetchH3Internals.liveCounts()` ends at `streams: 0`. - The original 30-round repro (canary `09bb54630`: 4 to 10 of 30 ok): 30 of 30 ok after the fix. **Self-review.** The review traced the lsquic calls state by state, the Rust lifecycle, and the tests. It found no defect. Addressed: - `abort()` had a contract that only a comment stated (`detach()` must follow). The fold into `detach_with` removes the contract and the repeated unbind block. - Each new comment is one line. - Test 2 says why the follow-up has a stream body. - Test 2 asserts that the server saw `content-length: 50`. - The matcher follows the repo idiom (`rejects.toMatchObject`). Not changed: - No test separates the `do_close` change in `us_quic_stream_reset` from the old call. It matters only when lsquic already reset the send half (the peer's STOP_SENDING came first), or when FIN is already out. The difference (prompt `on_close`, connection made tickable) shows in the lsquic log only, not in public behavior. - `us_quic_on_reset(how=0)` still closes with `lsquic_stream_close` when the *peer* resets the stream in the middle of an upload. That is the same FIN from a different trigger. The peer has abandoned the stream by then, an lsquic server discards the rest with no `content-length` check, and no test with Bun.serve as the peer can observe it. The function is shared with the server role, and #40598 changes it. - The STOP_SENDING that goes out with the reset still carries `H3_NO_ERROR`, as before. **Also not changed.** - `retry_or_fail` still refuses to re-send a stream body. #42579 and #41564 change its rules. This PR removes the trigger, not that rule. - lsquic treats a `content-length` mismatch as a connection error. RFC 9114 section 4.1.2 asks for a stream error, and section 8 lets an endpoint escalate. A conforming client no longer hits it on abort. **Related PRs.** #32678 describes the same lsquic guard and fixes only the malformed-response paths with a new `fail_malformed`. A user abort still sends FIN there. #40598 is the server-side mirror (a response body that fails mid-body). Both give `us_quic_stream_reset` an error-code parameter. The textual conflict with this PR is in that one function. #42024 is where CI first showed this failure (build 115613). Whichever of the two lands second should run test 2 again, because it sends a caller `content-length` with a stream body. **Tests.** The server route reports how the request body ended and which `content-length` it saw. The client aborts only after the server has read the first chunk, so the order is fixed. Test 2 also holds a response open on the pooled session across the abort and expects its full body afterwards. Its headers are in, so the client cannot move it to another session. The test releases it only after the server has seen the upload end: released sooner, it completes before the server closes anything, and the check passes on the released binary. On its own this check fails the released binary 5 of 5 runs (`Received: "first;"`). Released binary: `"body": "complete"` and `HTTP3StreamReset`, 7 of 7 runs. Debug build: 15 of 15 runs pass. The whole file also passes with the CI runner's ASAN settings (`BUN_JSC_validateExceptionChecks=1`, `BUN_DESTRUCT_VM_ON_EXIT=1`, `detect_leaks=1`). **Suites run on the debug ASAN build:** `fetch-http3-client` (58 pass), `serve-http3` (63), `serve-protocols` (20), `fetch-http3-adversarial` (27), `fetch-http3-cold-post` (2), `fetch-http3-syscall-fault` (7). </details> <!-- robobun:evidence:begin --> --- **[human-review]** gate passed · iteration 0 · 4 files touched <details><summary>fails on main (without fix)</summary> ```console ASAN without fix: 2 FAILED $ BUN_DEBUG_QUIET_LOGS=1 bun scripts/build.ts --profile=debug --quiet test "--reporter=junit" "--reporter-outfile=/tmp/pr_gate.xml" "test/js/web/fetch/fetch-http3-client.test.ts" bun test v1.4.3 (09bb546) test/js/web/fetch/fetch-http3-client.test.ts: (pass) fetch protocol: http3 > GET text [27.33ms] (pass) fetch protocol: http3 > 'h3' alias [8.13ms] (pass) fetch protocol: http3 > POST echo with headers [18.70ms] (pass) fetch protocol: http3 > JSON + query string [12.31ms] (pass) fetch protocol: http3 > route params [9.91ms] (pass) fetch protocol: http3 > large response body (multi-packet) [12.93ms] (pass) fetch protocol: http3 > large request body [19.44ms] (pass) fetch protocol: http3 > compress: gzip request body — small (shared-buffer fast path) [20.28ms] (pass) fetch protocol: http3 > compress: gzip request body — large (zlib-streaming spill path) [11.51ms] (pass) fetch protocol: http3 > status 200 [11.75ms] (pass) fetch protocol: http3 > status 204 [5.12ms] (pass) fetch protocol: http3 > status 404 [4.75ms] (pass) fetch protocol: http3 > status 500 [4.58ms] (pass) fetch protocol: http3 > HEAD has no body [11.08ms] (pass) fetch protocol: http3 > the respo ... (truncated) release without fix: all passed bun test v1.4.3-canary.1 (78ee3e0) test/js/web/fetch/fetch-http3-client.test.ts: (pass) fetch protocol: http3 > GET text [3.69ms] (pass) fetch protocol: http3 > 'h3' alias [0.99ms] (pass) fetch protocol: http3 > POST echo with headers [0.54ms] (pass) fetch protocol: http3 > JSON + query string [0.55ms] (pass) fetch protocol: http3 > route params [0.66ms] (pass) fetch protocol: http3 > large response body (multi-packet) [1.70ms] (pass) fetch protocol: http3 > large request body [27.82ms] (pass) fetch protocol: http3 > compress: gzip request body — small (shared-buffer fast path) [1.67ms] (pass) fetch protocol: http3 > compress: gzip request body — large (zlib-streaming spill path) [2.35ms] (pass) fetch protocol: http3 > status 200 [0.74ms] (pass) fetch protocol: http3 > status 204 [0.60ms] (pass) fetch protocol: http3 > status 404 [0.53ms] (pass) fetch protocol: http3 > status 500 [0.63ms] (pass) fetch protocol: http3 > HEAD has no body [0.30ms] (pass) fetch protocol: http3 > the response to a 204 has a null body [0.77ms] (pass) fetch protocol: http3 > the response to a 304 has a null body [0.17ms] (pass) fetch protocol: http3 > the response to a HEAD request ... (truncated) ``` </details> <details><summary>passes on PR (with fix)</summary> ```console ASAN with fix: all passed $ BUN_DEBUG_QUIET_LOGS=1 bun scripts/build.ts --profile=debug --quiet test "--reporter=junit" "--reporter-outfile=/tmp/pr_gate.xml" "test/js/web/fetch/fetch-http3-client.test.ts" bun test v1.4.3 (09bb546) test/js/web/fetch/fetch-http3-client.test.ts: (pass) fetch protocol: http3 > GET text [31.94ms] (pass) fetch protocol: http3 > 'h3' alias [7.56ms] (pass) fetch protocol: http3 > POST echo with headers [17.77ms] (pass) fetch protocol: http3 > JSON + query string [11.34ms] (pass) fetch protocol: http3 > route params [10.21ms] (pass) fetch protocol: http3 > large response body (multi-packet) [13.25ms] (pass) fetch protocol: http3 > large request body [19.02ms] (pass) fetch protocol: http3 > compress: gzip request body — small (shared-buffer fast path) [19.79ms] (pass) fetch protocol: http3 > compress: gzip request body — large (zlib-streaming spill path) [11.73ms] (pass) fetch protocol: http3 > status 200 [10.20ms] (pass) fetch protocol: http3 > status 204 [4.15ms] (pass) fetch protocol: http3 > status 404 [3.56ms] (pass) fetch protocol: http3 > status 500 [3.22ms] (pass) fetch protocol: http3 > HEAD has no body [9.56ms] (pass) fetch protocol: http3 > the respo ... (truncated) release with fix: all passed $ bun scripts/build.ts --profile=release [configured] bun-profile → bun (stripped) in 904ms (unchanged) ninja: Entering directory `/workspace/bun/build/release' [1/9] cc obj/packages/bun-usockets/src/quic.c.o [2/9] gen generated_host_exports.rs generated_host_exports.rs: 122 exports (host=5, lazy=10, generic=107, rust=0); 243 extern-C blocks audited [2/9] cargo bun_runtime → libbun_runtime.a �[1m�[92m Compiling�[0m bun_core v0.0.0 (/workspace/bun/src/bun_core) �[1m�[92m Compiling�[0m bun_errno v0.0.0 (/workspace/bun/src/errno) �[1m�[92m Compiling�[0m bun_ptr v0.0.0 (/workspace/bun/src/ptr) �[1m�[92m Compiling�[0m bun_boringssl_sys v0.0.0 (/workspace/bun/src/boringssl_sys) �[1m�[92m Compiling�[0m bun_safety v0.0.0 (/workspace/bun/src/safety) �[1m�[92m Compiling�[0m bun_base64 v0.0.0 (/workspace/bun/src/base64) �[1m�[92m Compiling�[0m bun_cares_sys v0.0.0 (/workspace/bun/src/cares_sys) �[1m�[92m Compiling�[0m bun_zlib_sys v0.0.0 (/workspace/bun/src/zlib_sys) �[1m�[92m Compiling�[0m bun_zstd v0.0.0 (/workspace/bun/src/zstd) �[1m�[92m Compiling�[0m bun_paths v0.0.0 (/workspace/bun/src/paths) �[1m�[92m Compiling�[0m bun_collections v0.0.0 (/work ... (truncated) ``` </details> <details><summary>diff hotspot</summary> ``` packages/bun-usockets/src/quic.c | 8 +- src/http/h3_client/ClientSession.rs | 13 ++-- src/http/h3_client/Stream.rs | 8 +- test/js/web/fetch/fetch-http3-client.test.ts | 108 +++++++++++++++++++++++++++ 4 files changed, 123 insertions(+), 14 deletions(-) ``` </details> **gate history** · 2 passed · 0 rejected · iteration 0 <details><summary>evidence per changed file</summary> ``` file reads edits tests packages/bun-usockets/src/quic.c 4 4 18 src/http/h3_client/ClientSession.rs 4 7 18 src/http/h3_client/Stream.rs 4 6 18 test/js/web/fetch/fetch-http3-client.test.ts 4 8 18 ``` </details> <!-- robobun:evidence:end -->
usrbinkat
pushed a commit
to usrbinkat/bun
that referenced
this pull request
Sep 15, 2026
### Problem - Over HTTP/3, an aborted `fetch()` upload ends with FIN, not RESET_STREAM. The server takes the truncated body for a complete request: `await req.text()` resolves `"hello "`. HTTP/1.1 reports an abort. - With a declared `content-length`, the server's lsquic answers the short FIN with CONNECTION_CLOSE (`H3_MESSAGE_ERROR`). The next stream upload on the pooled session rejects with `TypeError: HTTP3StreamReset fetching ...` (20 to 26 of 30 rounds). - Cause: `ClientSession::fail` (`src/http/h3_client/ClientSession.rs:206`) calls `Stream::abort()` (`lsquic_stream_close`) before `detach()`. The close queues FIN and sets `STREAM_U_WRITE_DONE`, so the `reset()` in `detach()` sends nothing. ### Fix - `fail()` and `retry_or_fail()` call `detach_with(stream, true)`, the teardown behind `detach()`. They no longer close the lsquic stream first. An unfinished send half ends with `RESET_STREAM(H3_REQUEST_CANCELLED)`. A finished one closes as before. `Stream::abort()` is gone. - `us_quic_stream_reset` always ends with `lsquic_stream_close`. `lsquic_stream_maybe_reset` shuts only the read half when no RESET_STREAM is due. - Correct per RFC 9114 section 4.1.1: RESET_STREAM cancels a request. The HTTP/2 client sends RST_STREAM(CANCEL) here. - Verified: `test/js/web/fetch/fetch-http3-client.test.ts` (2 new tests, the released binary fails both) and five other HTTP/3 suites. Self-reviewed: 10 concerns, 7 addressed (Notes). ### Background - The fetch HTTP/3 client pools one `ClientSession` (one QUIC connection) per origin. Each request is a `Stream` bound to one lsquic stream. - FIN ends the send half of a QUIC stream: "this is the whole message". RESET_STREAM aborts it. - lsquic checks a declared `content-length` when it reads the FIN (`verify_cl_on_fin`). A mismatch closes the whole connection. - `fail()` is the client's error path (user abort, malformed response, decode error). `detach()` tears down every request. <details><summary>Notes</summary> **lsquic calls.** `lsquic_stream_close` runs `stream_shutdown_write`. That sets `STREAM_U_WRITE_DONE` and queues FIN when the headers are out. `lsquic_stream_maybe_reset` sends RESET_STREAM only when none of `STREAM_RST_SENT`, `STREAM_FIN_SENT`, `STREAM_U_WRITE_DONE`, `SMQF_SEND_RST` is set. With `do_close`, its other branch runs `stream_shutdown_read` only. That does not set `STREAM_U_WRITE_DONE`, does not make the connection tickable, and does not call `maybe_schedule_call_on_close`. So `us_quic_stream_reset` now calls `lsquic_stream_maybe_reset(.., 0)` and then `lsquic_stream_close`. In the reset branch this equals the old `do_close=1` (`stream_reset` ends in `lsquic_stream_close`). In the other branch it is a full close. Neither call runs a stream callback synchronously. **Shape of the Rust change.** `detach()` is now a wrapper for `detach_with(stream, false)`. `detach_with` holds the old body of `detach()`, and its reset condition is `abort || !request_body_done`. `fail()` and `retry_or_fail()` call `detach_with(stream, true)` where they called `Stream::abort()` and then `detach()`. One function unbinds, resets and frees, so no caller can leave an unbound entry in `pending` (which `on_stream_open` would bind to a new lsquic stream), and lsquic sees one close per stream. **Wire, before** (`BUN_DEBUG_lsquic=1`): ``` stream: lsquic_stream_close() called stream: have to create a separate STREAM frame with FIN flag in it conn: generated 4-byte STOP_SENDING frame (stream id: 4, error code: 256) conn: abort error: is_app: 1; error code: 270; error str: number of bytes in DATA frames of stream 4 is 6, while content-length specified of 50 [h3_client] stream_close status=0 delivered=false [h3_client] conn_close status=8 '' ``` **Wire, after:** ``` stream: reset, error code 268 event: generated RESET_STREAM: stream 4; offset 75; error code 268 event: RX RST_STREAM frame: error code 268, stream 4, offset: 75 ``` The next upload runs on the same session. **Probes by hand (debug ASAN build).** - A Buffer body aborted while the handler waits. Before (64 MB): the handler saw `complete 40702` and `complete 103029` (bytes) in 2 of 3 rounds. After (16 MB): `aborted AbortError` in 3 of 3 rounds. String and Buffer bodies take the same `abort()` path. - A server that responds without reading the body (Bun.serve sends STOP_SENDING), with and without an abort during the response: same result before and after. Each request stream gets its lsquic `on_close` on both endpoints at once, not at connection teardown. `fetchH3Internals.liveCounts()` ends at `streams: 0`. - The original 30-round repro (canary `09bb54630`: 4 to 10 of 30 ok): 30 of 30 ok after the fix. **Self-review.** The review traced the lsquic calls state by state, the Rust lifecycle, and the tests. It found no defect. Addressed: - `abort()` had a contract that only a comment stated (`detach()` must follow). The fold into `detach_with` removes the contract and the repeated unbind block. - Each new comment is one line. - Test 2 says why the follow-up has a stream body. - Test 2 asserts that the server saw `content-length: 50`. - The matcher follows the repo idiom (`rejects.toMatchObject`). Not changed: - No test separates the `do_close` change in `us_quic_stream_reset` from the old call. It matters only when lsquic already reset the send half (the peer's STOP_SENDING came first), or when FIN is already out. The difference (prompt `on_close`, connection made tickable) shows in the lsquic log only, not in public behavior. - `us_quic_on_reset(how=0)` still closes with `lsquic_stream_close` when the *peer* resets the stream in the middle of an upload. That is the same FIN from a different trigger. The peer has abandoned the stream by then, an lsquic server discards the rest with no `content-length` check, and no test with Bun.serve as the peer can observe it. The function is shared with the server role, and oven-sh#40598 changes it. - The STOP_SENDING that goes out with the reset still carries `H3_NO_ERROR`, as before. **Also not changed.** - `retry_or_fail` still refuses to re-send a stream body. oven-sh#42579 and oven-sh#41564 change its rules. This PR removes the trigger, not that rule. - lsquic treats a `content-length` mismatch as a connection error. RFC 9114 section 4.1.2 asks for a stream error, and section 8 lets an endpoint escalate. A conforming client no longer hits it on abort. **Related PRs.** oven-sh#32678 describes the same lsquic guard and fixes only the malformed-response paths with a new `fail_malformed`. A user abort still sends FIN there. oven-sh#40598 is the server-side mirror (a response body that fails mid-body). Both give `us_quic_stream_reset` an error-code parameter. The textual conflict with this PR is in that one function. oven-sh#42024 is where CI first showed this failure (build 115613). Whichever of the two lands second should run test 2 again, because it sends a caller `content-length` with a stream body. **Tests.** The server route reports how the request body ended and which `content-length` it saw. The client aborts only after the server has read the first chunk, so the order is fixed. Test 2 also holds a response open on the pooled session across the abort and expects its full body afterwards. Its headers are in, so the client cannot move it to another session. The test releases it only after the server has seen the upload end: released sooner, it completes before the server closes anything, and the check passes on the released binary. On its own this check fails the released binary 5 of 5 runs (`Received: "first;"`). Released binary: `"body": "complete"` and `HTTP3StreamReset`, 7 of 7 runs. Debug build: 15 of 15 runs pass. The whole file also passes with the CI runner's ASAN settings (`BUN_JSC_validateExceptionChecks=1`, `BUN_DESTRUCT_VM_ON_EXIT=1`, `detect_leaks=1`). **Suites run on the debug ASAN build:** `fetch-http3-client` (58 pass), `serve-http3` (63), `serve-protocols` (20), `fetch-http3-adversarial` (27), `fetch-http3-cold-post` (2), `fetch-http3-syscall-fault` (7). </details> <!-- robobun:evidence:begin --> --- **[human-review]** gate passed · iteration 0 · 4 files touched <details><summary>fails on main (without fix)</summary> ```console ASAN without fix: 2 FAILED $ BUN_DEBUG_QUIET_LOGS=1 bun scripts/build.ts --profile=debug --quiet test "--reporter=junit" "--reporter-outfile=/tmp/pr_gate.xml" "test/js/web/fetch/fetch-http3-client.test.ts" bun test v1.4.3 (09bb546) test/js/web/fetch/fetch-http3-client.test.ts: (pass) fetch protocol: http3 > GET text [27.33ms] (pass) fetch protocol: http3 > 'h3' alias [8.13ms] (pass) fetch protocol: http3 > POST echo with headers [18.70ms] (pass) fetch protocol: http3 > JSON + query string [12.31ms] (pass) fetch protocol: http3 > route params [9.91ms] (pass) fetch protocol: http3 > large response body (multi-packet) [12.93ms] (pass) fetch protocol: http3 > large request body [19.44ms] (pass) fetch protocol: http3 > compress: gzip request body — small (shared-buffer fast path) [20.28ms] (pass) fetch protocol: http3 > compress: gzip request body — large (zlib-streaming spill path) [11.51ms] (pass) fetch protocol: http3 > status 200 [11.75ms] (pass) fetch protocol: http3 > status 204 [5.12ms] (pass) fetch protocol: http3 > status 404 [4.75ms] (pass) fetch protocol: http3 > status 500 [4.58ms] (pass) fetch protocol: http3 > HEAD has no body [11.08ms] (pass) fetch protocol: http3 > the respo ... (truncated) release without fix: all passed bun test v1.4.3-canary.1 (78ee3e0) test/js/web/fetch/fetch-http3-client.test.ts: (pass) fetch protocol: http3 > GET text [3.69ms] (pass) fetch protocol: http3 > 'h3' alias [0.99ms] (pass) fetch protocol: http3 > POST echo with headers [0.54ms] (pass) fetch protocol: http3 > JSON + query string [0.55ms] (pass) fetch protocol: http3 > route params [0.66ms] (pass) fetch protocol: http3 > large response body (multi-packet) [1.70ms] (pass) fetch protocol: http3 > large request body [27.82ms] (pass) fetch protocol: http3 > compress: gzip request body — small (shared-buffer fast path) [1.67ms] (pass) fetch protocol: http3 > compress: gzip request body — large (zlib-streaming spill path) [2.35ms] (pass) fetch protocol: http3 > status 200 [0.74ms] (pass) fetch protocol: http3 > status 204 [0.60ms] (pass) fetch protocol: http3 > status 404 [0.53ms] (pass) fetch protocol: http3 > status 500 [0.63ms] (pass) fetch protocol: http3 > HEAD has no body [0.30ms] (pass) fetch protocol: http3 > the response to a 204 has a null body [0.77ms] (pass) fetch protocol: http3 > the response to a 304 has a null body [0.17ms] (pass) fetch protocol: http3 > the response to a HEAD request ... (truncated) ``` </details> <details><summary>passes on PR (with fix)</summary> ```console ASAN with fix: all passed $ BUN_DEBUG_QUIET_LOGS=1 bun scripts/build.ts --profile=debug --quiet test "--reporter=junit" "--reporter-outfile=/tmp/pr_gate.xml" "test/js/web/fetch/fetch-http3-client.test.ts" bun test v1.4.3 (09bb546) test/js/web/fetch/fetch-http3-client.test.ts: (pass) fetch protocol: http3 > GET text [31.94ms] (pass) fetch protocol: http3 > 'h3' alias [7.56ms] (pass) fetch protocol: http3 > POST echo with headers [17.77ms] (pass) fetch protocol: http3 > JSON + query string [11.34ms] (pass) fetch protocol: http3 > route params [10.21ms] (pass) fetch protocol: http3 > large response body (multi-packet) [13.25ms] (pass) fetch protocol: http3 > large request body [19.02ms] (pass) fetch protocol: http3 > compress: gzip request body — small (shared-buffer fast path) [19.79ms] (pass) fetch protocol: http3 > compress: gzip request body — large (zlib-streaming spill path) [11.73ms] (pass) fetch protocol: http3 > status 200 [10.20ms] (pass) fetch protocol: http3 > status 204 [4.15ms] (pass) fetch protocol: http3 > status 404 [3.56ms] (pass) fetch protocol: http3 > status 500 [3.22ms] (pass) fetch protocol: http3 > HEAD has no body [9.56ms] (pass) fetch protocol: http3 > the respo ... (truncated) release with fix: all passed $ bun scripts/build.ts --profile=release [configured] bun-profile → bun (stripped) in 904ms (unchanged) ninja: Entering directory `/workspace/bun/build/release' [1/9] cc obj/packages/bun-usockets/src/quic.c.o [2/9] gen generated_host_exports.rs generated_host_exports.rs: 122 exports (host=5, lazy=10, generic=107, rust=0); 243 extern-C blocks audited [2/9] cargo bun_runtime → libbun_runtime.a �[1m�[92m Compiling�[0m bun_core v0.0.0 (/workspace/bun/src/bun_core) �[1m�[92m Compiling�[0m bun_errno v0.0.0 (/workspace/bun/src/errno) �[1m�[92m Compiling�[0m bun_ptr v0.0.0 (/workspace/bun/src/ptr) �[1m�[92m Compiling�[0m bun_boringssl_sys v0.0.0 (/workspace/bun/src/boringssl_sys) �[1m�[92m Compiling�[0m bun_safety v0.0.0 (/workspace/bun/src/safety) �[1m�[92m Compiling�[0m bun_base64 v0.0.0 (/workspace/bun/src/base64) �[1m�[92m Compiling�[0m bun_cares_sys v0.0.0 (/workspace/bun/src/cares_sys) �[1m�[92m Compiling�[0m bun_zlib_sys v0.0.0 (/workspace/bun/src/zlib_sys) �[1m�[92m Compiling�[0m bun_zstd v0.0.0 (/workspace/bun/src/zstd) �[1m�[92m Compiling�[0m bun_paths v0.0.0 (/workspace/bun/src/paths) �[1m�[92m Compiling�[0m bun_collections v0.0.0 (/work ... (truncated) ``` </details> <details><summary>diff hotspot</summary> ``` packages/bun-usockets/src/quic.c | 8 +- src/http/h3_client/ClientSession.rs | 13 ++-- src/http/h3_client/Stream.rs | 8 +- test/js/web/fetch/fetch-http3-client.test.ts | 108 +++++++++++++++++++++++++++ 4 files changed, 123 insertions(+), 14 deletions(-) ``` </details> **gate history** · 2 passed · 0 rejected · iteration 0 <details><summary>evidence per changed file</summary> ``` file reads edits tests packages/bun-usockets/src/quic.c 4 4 18 src/http/h3_client/ClientSession.rs 4 7 18 src/http/h3_client/Stream.rs 4 6 18 test/js/web/fetch/fetch-http3-client.test.ts 4 8 18 ``` </details> <!-- robobun:evidence:end -->
This was referenced Sep 16, 2026
Open
Jarred-Sumner
pushed a commit
that referenced
this pull request
Sep 17, 2026
#42900) ### Problem - An HTTP/3 `fetch()` whose QUIC connection dies before the response header can abort the process. ASan: `heap-use-after-free READ of size 8` in `HTTPClient::fail_from_h2` (`src/http/lib.rs:2108`), from `ClientSession::retry_or_fail` (`src/http/h3_client/ClientSession.rs:288`). Release builds panic: `fetch on the HTTP thread holds a ticket`. - The retry queues the request on a new session through `ClientContext::connect`. When no connection opens, connect fails that session with `PendingConnect::fail_session`, which fails every request queued on it. That dispatch frees the `AsyncHTTP` the client is part of. Then the retry fails the same client again. ### Fix - `connect` takes the request back off the session before it fails that session. A `false` return leaves the request on no session, so the caller is its only failure path, which is what the other two callers assume. - Correct because the session is one call old: the request `enqueue` just queued is its only entry, so `detach` leaves `fail_session` nothing to fail. The teardown, the registry removal and the session's last reference do not change. - The retried request keeps the error of the stream that closed. `start_` still reports `ConnectionRefused` for its own failed connect. - Verified: `test/js/web/fetch/fetch-http3-client.test.ts`, one new test (main aborts with an empty stdout). Also the three other `fetch-http3-*` suites, `serve-http3` and `serve-protocols`. ### Background - The h3 fetch client pools one QUIC connection per origin. `retry_or_fail` re-sends a stream that closed before any response header, once, on a fresh connection. - `ClientContext::connect` finds a pooled connection or opens one, and queues the request. `enqueue` binds a `Stream` to the request before the QUIC connect, because that stream has to exist when the handshake completes. - `HTTPClient::start_` sets `defer_terminal_dispatch_until_connecting_is_complete` before its own connect call, so a failure inside that frame is recorded and dispatched later. That flag is why the two initial connect sites survived the double failure. <details><summary>Notes</summary> **Fail-before.** With `src/` and `packages/` back on `55c11065f2`, the new test gives `exitCode: 1` and an empty stdout. That run, the passing run and the suites above were on `55c11065f2` plus this change, built with LLVM 21. The branch has since merged main, which needs LLVM 23 (#42851). The build environment used here does not have it, so on the merged tree only `cargo check` and `cargo clippy` for `bun_http` were run locally, and CI is the test run for it. The three commits that merge brought in touch none of the files involved. The ASan frames are the report above: ``` READ of size 8 at 0x... thread T4 (HTTP Client) #2 <bun_http::HTTPClient>::fail_from_h2 src/http/lib.rs:2108 #3 <ClientSession>::retry_or_fail src/http/h3_client/ClientSession.rs:288 #4 h3_client::callbacks::on_conn_close src/http/h3_client/callbacks.rs:151 freed by thread T4 (HTTP Client) here: #7 <AsyncHTTP>::on_async_http_callback_raw src/http/AsyncHTTP.rs:783 #10 <bun_http::HTTPClient>::fail_from_h2 src/http/lib.rs:2122 #11 <PendingConnect>::fail_session src/http/h3_client/PendingConnect.rs:149 #12 <ClientContext>::connect src/http/h3_client/ClientContext.rs:179 #13 <ClientSession>::retry_or_fail src/http/h3_client/ClientSession.rs:287 ``` A release build aborts as well, so the fault is not an ASan artifact: `on_async_http_callback_raw` resets the client's stage before the dealloc, so the once-only guard in `fail_from_h2` cannot stop the second dispatch. Making that guard survive the reset is a separate change. **How the test reaches it.** A connect to a resolved hostname probes each address with a throwaway UDP `connect(2)`, and gives up when no entry is reachable (`packages/bun-usockets/src/quic.c`, `us_quic_connect_result`). An `LD_PRELOAD` shim allows the first probe and refuses every later one, so the reconnect fails inside `connect`. `rejectUnauthorized` against the suite's self-signed certificate fails the handshake, which is what closes the stream before any header and starts the retry. `localhost` answers from `is_localhost_name` as `[::1, 127.0.0.1]` without the resolver, so no connect waits for DNS, and the shim refuses the IPv6 entry the way a host without an IPv6 route does, which pins both connects to the same address. Linux only, and only where a C compiler exists, like the DPLPMTUD shim test in `fetch-http3-syscall-fault.test.ts`. 5 runs, 5 passes, about 500 ms each on the debug ASan build. **Other ways to reach the same failure.** Any synchronous failure of the QUIC connect does it: a cached resolver error, an IP literal whose family the shared client endpoint cannot serve, `lsquic_engine_connect` returning NULL, or the shared client UDP endpoint dying on a hard `recvmsg` error and the poll registration for its replacement failing. The last one needs no resolver, so it reaches this path for an IP-literal origin too. One test is enough: all of them end in the same `return false`, and the endpoint-replacement route needs several iterations of a loop to line up. **Earlier shape.** The first version of this PR removed the retry's failure call instead, and documented `connect` as owning the request. Review pushed back: it left both `if !connect { self.fail(..) }` arms in `start_` dead, it made the bool unusable by every caller, and it set the opposite contract from #40385, which removes the same double failure from the callee side. This version fixes the callee, which also keeps the closed stream's error in the rejection instead of replacing it with `ECONNREFUSED`. **Scope.** `retry_or_fail` is also edited by #41564 (a retry budget) and #42579 (no replay of a non-idempotent request), and #40598 changes which pre-header closes retry. None of them touch this branch, so this applies on top of any of them, and #40385 keeps the same contract. </details> <!-- robobun:evidence:begin --> --- **no test proof** · iteration 1 · platform-specific test(s) that do not run on this machine, deferring to CI, which covers all platforms: test/js/web/fetch/fetch-http3-client.test.ts <!-- robobun:evidence:end -->
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Problem
Bun.serveResponse body stream that errors after some chunks were sent is delivered as a complete message.fetch(url, { protocol: "http3" })resolves with status 200 andres.text()resolves with the bytes sent so far. HTTP/1.1 closes the connection without the chunked terminator for the same case, so the client seesECONNRESET.RequestContext::force_close()is the "signal an incomplete message" path. For H3 it reacheduws_h3_res_force_close(src/uws_sys/libuwsockets_h3.cpp), which calledus_quic_stream_close(). That queues a FIN after the buffered tail, and in HTTP/3 a FIN is the end-of-message marker.src/http/h3_client/callbacks.rs,on_stream_close) treated every stream close after the response headers as a clean end of body, even a peer RESET_STREAM or a CONNECTION_CLOSE. Before the headers it re-sent the request once for any close, including a RESET_STREAM that means the server may have run the handler.Fix
uws_h3_res_force_closesendsRESET_STREAM(H3_INTERNAL_ERROR).us_quic_stream_resettakes the code as a parameter,quic.crecords a peer RESET_STREAM with its code, and the codes live in one place: the RustH3ErrorCodeenum insrc/uws_sys/quic/Stream.rs.on_stream_closenow callsClientSession::on_stream_closedwith the peer's reset code. A FIN always detaches the stream insidedeliver, so a stream still attached at close never got one. After the headers the request fails withHTTP3StreamReset(peer reset) orConnectionClosed(ECONNRESETin JS, the HTTP/1.1 code for a connection dropped mid-body). Before the headers it is re-sent once only when the connection went away or the code isH3_REQUEST_REJECTED, the one code that promises no application processing (RFC 9114 section 8.1). The h2 client retries onlyREFUSED_STREAMthe same way.http2: true#40137 sendsRST_STREAM(INTERNAL_ERROR)fromforce_closefor the same reason.test/js/bun/http/serve-http3.test.ts(2 new tests:fetch()body read rejects,node:quicseesRESET_STREAMcode 258) andtest/js/web/fetch/fetch-http3-client.test.ts(4 new tests against anode:quicserver: RESET_STREAM mid-body, CONNECTION_CLOSE mid-body, pre-header reset with 0x10B re-sent once, with 0x102 not re-sent). Five fail with main'ssrc/andpackages/. Also ran the fullserve-http3,fetch-http3-*, andtest/js/node/quicsuites andbun run rust:check-all.Background
RESET_STREAM(error code)(RFC 9000 section 3.2, RFC 9114 section 8.1).us_quic_stream_close(packages/bun-usockets/src/quic.c) wrapslsquic_stream_close, which shuts down both halves and queues a FIN.us_quic_stream_resetwrapslsquic_stream_maybe_reset, which drops the unsent tail and queuesRESET_STREAMinstead.on_reset(how=0)and later callson_close. It never reports a FIN for that stream, soon_stream_data(fin=1)does not run. The fetch client learns of a FIN only through that callback.ClientSession::retry_or_fail) exists for a pooled session that went stale (GOAWAY, stateless reset, port reuse). It re-sends the request on a fresh session, so it is safe only when the server did not process the first copy.Notes
Repro on main (debug build):
status=200 body-resolved len=2048for a stream that enqueues two 1 KiB chunks and then callscontroller.error(). With the fix:fetch()resolves with status 200,res.text()rejects withcode: "HTTP3StreamReset", and a following request on the same connection succeeds.A
node:quicclient reading the same response getsERR_QUIC_STREAM_RESETfrom its iterator and itsclosedpromise rejects withERR_QUIC_APPLICATION_ERROR,errorCode258 (0x102). It discards body bytes its reader has not consumed when the reset arrives (RFC 9000 section 3.2 allows this), so the test asserts the status and how the stream ended, not a byte count. The fixtures order the wire without a sleep: the body source fails only after the client, which by then holds the status and the first chunk, requests/release.The "error before the first chunk" case is unchanged here: it still takes
end_stream()and sends headers plus FIN, so the client sees a 200 with an empty body. #40596 routes that case throughforce_close()for HTTP/1.1 and leaves the H3 close semantics to this PR. With both,Bun.servesendsRESET_STREAM(H3_INTERNAL_ERROR)before the headers and this client fails withHTTP3StreamResetwithout re-sending the request. On the client code of main a pre-header reset re-sends the request once (verified against anode:quicserver: two POSTs reach the handler), so this PR should land before #40596.FileResponseStream.rsalso callsforce_close()when a file read fails mid-response, so that path now resets the H3 stream too.Client side: the
Abortedcheck inon_stream_closedkeeps the orderdeliverhad (an aborted request reportsAborted, not the transport error).fail()callsStream::abort(), which is a no-op here becauseqstreamwas already cleared, so the dying lsquic stream is not touched. TheH3_REQUEST_REJECTEDretry test pins the existing retry path (it passes on main too); theH3_INTERNAL_ERRORone fails on main.Suites run with the debug build:
test/js/bun/http/serve-http3.test.ts(54 pass),test/js/web/fetch/fetch-http3-client.test.ts(60 pass),fetch-http3-adversarial,fetch-http3-cold-post,fetch-http3-syscall-fault,test/js/node/quic/(49 pass).[review] gate passed · iteration 1 · 10 files touched
fails on main (without fix)
passes on PR (with fix)
diff hotspot
gate history · 2 passed · 0 rejected · iteration 1
evidence per changed file