Files
alkhttp/fuzz
glm-5.3-flash b78b9a2618 fix(fuzzing): FWD-22 — guard-CR re-frame makes the SSE round-trip total
The sse_parser re-frame probe emitted 'data: <line>' unguarded, so a
payload CR (interior CR in multi-line data: the payload line is '\r')
was consumed by strip_cr at re-parse time and the round-trip lost it.
Wave 1 had skipped only the terminal-CR case. Found ~32 min into the
first 45-min sse_parser campaign.

- frame_event emits 'data: <line>\r': the guard CR is the line
  terminator, strip_cr removes exactly it, the payload CR survives
- drop the terminal-CR skip; the round trip is now total over
  JSON-encodable payloads (JSON never encodes a raw CR, so the
  residual asymmetry is the serde_json non-preserved key-order class)
- no crate-side change: the parser was correct (data: x\r\r\n ->
  x\r); only the harness re-encode was weak
- regression: 2 new seeds (interior CR via \r escape; raw CR via CRLF
  framing, two-line doc) + unit cases

Verification: shared 21/21 (default + no-default-features), main
crate green, clippy -D warnings clean, fmt clean, cargo fuzz build
clean
2026-09-29 19:25:39 +00:00
..

alkhttp fuzzing

cargo-fuzz targets for the HTTP surface's hand-rolled parse paths. The design and operating rules live in docs/plans/fuzzing.md (adopted from alkcall's docs/research/fuzzing.md); this README is the operational cheat-sheet.

Layout

  • fuzz_targets/ — nightly-only fuzz_target! binaries (thin wrappers).
  • shared/ — stable-toolchain library holding the invariant logic; the corpus replay tests run here on plain cargo test.
  • corpus/<target>/ — committed seeds (regenerate with python3 fuzz/gen_fuzz_seeds.py).
  • artifacts/ — gitignored crash/oom/timeout artifacts + campaign logs.

Targets

Target Drives
sse_parser SseParser::feed + the FWD-17 envelope mapping (src/adapters/forward.rs) — the SSE frame parser every subscription forwards through
ws_chunk_framing WriteChunkWalk (the write pump's chunk walk) (src/websocket/byte_adapter.rs)
spec_import OpenAPISpec::from_str/from_yaml/from_json, the YAML normalization boundary, CompiledInputSchema compile/harden/validate, FromMCP::build_spec (src/adapters/openapi_spec.rs, input_validation.rs, from_mcp/mod.rs)
ws_session_opseq stateful op sequences over the WS byte adapter's generic pumps (run_read_pump/run_write_pump over the mock socket flavor) — interleavings, close timing, loud-gate mapping, backpressure
retry_throttle the inlined RetryAfterMiddleware's throttle map: capacity bound, eviction policy, ceiling clamp, refresh contraction, Retry-After parse partition

Running a campaign — always detached

Agent sessions must never run fuzzing in the foreground (an OOM in a target can take down the session host; see docs/plans/fuzzing.md §2). Use the detached runner:

fuzz/run-detached.sh sse_parser
# poll:
tail -n 50 fuzz/artifacts/sse_parser-*.log
ls fuzz/artifacts/sse_parser/
pgrep -f "cargo fuzz run sse_parser"

FUZZ_RUNTIME_SECS=1800 fuzz/run-detached.sh sse_parser for a longer campaign. The runner pins -fork=1 -rss_limit_mb=2048 -malloc_limit_mb=2048 -timeout=25 and detaches via setsid + nohup.

Corpus replay (the standing fuzz gate)

cargo test --manifest-path fuzz/shared/Cargo.toml

Replays every committed seed through the same invariant functions the fuzzer runs, on stable, no nightly needed. Part of the release verification checklist (AGENTS.md).

Toolchain notes

rust-toolchain.toml pins nightly for this subtree only (llvm-tools required by cargo-fuzz); the crate itself stays on stable at MSRV 1.88. cargo fuzz build must be run with the fuzz dir as CWD or trust the toolchain file (rustup resolves per directory).

Run campaigns before releases and after touching src/adapters/forward.rs (the SSE parser), src/websocket/byte_adapter.rs (the WS chunk walk), or the import adapters (src/adapters/openapi_spec.rs, input_validation.rs, from_mcp/).