glm-5.3-flash
e3c6f6c9f8
The wave-2 stateful target from docs/research/fuzzing.md 3.3: op sequences (arbitrary SessionSequence) over one live channels stack per exec - MuxRunner -> raw chunk stream -> the real run_demux_loop_for_client demux -> ChannelManager per side (producer Connect / consumer Accept over one duplex transport, the reverse POC's topology). The harness mirrors TunnelSession's data-plane shapes: datagram planes (codec reader + pending, the DatagramHalves mirror) and stream planes (pump_bidi against in-process peer halves, the pump_against mirror). Invariants (3.3): no-panic/no-wedge (5s reconcile join); two-pump shutdown-on-completion; lossless p2c copy count; EOF-sentinel teardown semantics (drain-before-EOF, map empties); FIFO datagram reconciliation through the real demux path (stateful framing walk, the wave-1 walk carried across ops); the 1.3 DatagramHalves.pending backlog bound (<= routed-but-unpulled remainder); decoder-state retained-bytes bound re-asserted per op. Harness-model findings (all six wave findings are harness defects, not crate bugs - the fuzzer-as-harness-checker pattern): - duplicate adopt is a legal ChannelExists no-op (documented table) - the p2c-EOF pump join is the DESIGNED half-close shape; the pump completes once the c2p source EOFs too (teardown), not before - route_payload routes into the LOCAL manager (demux direction); the producer pump writes the channel send half - the first campaign's bytes never reached the consumer; rewritten to the real protocol shape (Open allocates, session-index addressing, stateful framing model, Pull op, EOF sentinels only from teardown/sender-drop) - clear_all's return is the opener-ledger records, NOT the reaped ids (adopted channels carry no ledger entry - the alkcall 7.7 lesson re-learned); the map-empties assert is the ground truth Campaign (10-min detached, 6 runner): 228,676 execs, 32 fork jobs, oom/timeout/crash 0/0/0, exit 0. Coverage 3427 edges / 17.5k features still expanding at budget end. No crate bugs found - the two-pump contract, EOF-sentinel semantics, and the pending backlog bound are demonstrated properties. Crate addition: TunnelSession::datagram_backlog() (the DatagramHalves.pending diagnostic the 3.3 bound asserts against, in the retained_bytes() style) + a suite test pinning its rest states. Verification: main suite 136 passed; corpus replay (8 committed seeds + 2 semantic fixtures) green; clippy -D warnings + fmt clean (main, shared, wasm); wasm check clean; cargo fuzz build clean.
alktunnels fuzzing
libFuzzer targets for alktunnels' untrusted-input surfaces (see
docs/research/fuzzing.md for the full rationale, scope decision, and
campaign plan; the tooling/corpus/runner/no-CI posture is inherited
from alkcall's docs/research/fuzzing.md).
Layout
fuzz_targets/— one binary per target; thinfuzz_target!wrappers.shared/— the invariant logic, as a plain library so normalcargo test(stable toolchain) can replay the committed corpora through the same invariants (fuzz/shared/src/*.rs#[cfg(test)]modules; quinn's CI pattern). The fuzz binaries are nightly-only; the shared crate is stable-clean.corpus/<target>/— committed hand-made seeds (regenerate withpython3 fuzz/gen_fuzz_seeds.pyfrom the repo root). Grown corpora and artifacts are gitignored.run-detached.sh— mandatory runner for agent sessions: wrapscargo fuzz runinsetsid+nohup+ log redirection so an OOM in a target can never take down the agent host (fuzzing.md §5).json.dict— JSON token dictionary for the params target (transferred from alkcall).
Targets
| Target | Drives | Invariants |
|---|---|---|
datagram_codec |
DatagramReader::feed / frame_datagram (src/wire.rs) |
no-panic; infallible decode; yielded datagrams ≤ MAX_DATAGRAM_LEN; F-2 sentinel layering (empty datagram ≠ EOF, only from [00 00] headers); splitting transparency (3-byte slices == whole-input feed); re-frame round-trip; oversize rejection exactly at the bound; is_mid_datagram tracks framing; decoder-state retained-bytes bound |
params_parse |
TunnelParams / TunnelDirectParams / TunnelForwardedParams / SubstrateAddr serde parses + parse_listen_reply / listen_reply_fields / establishment_reason (src/params.rs) |
no-panic on raw bytes and structured Values; clean typed failure only; round-trip for valid params; listen: 0 pin; loud/lenient projection-pair agreement; pinned establishment-reason table |
session_pumps |
op sequences (SessionSequence) over one live channels stack per exec (MuxRunner → real demux → ChannelManager per side; the TunnelSession data-plane mirrors — codec plane + pump_bidi stream planes) |
no-panic / no-wedge (5 s reconcile bound); two-pump shutdown-on-completion; lossless p2c copy count; EOF-sentinel teardown semantics (drain-before-EOF, map empties); FIFO datagram reconciliation (framing-walk model); pending backlog ≤ routed-batch remainder (the §1.3 bound); decoder-state retained-bytes bound re-asserted per op; monotonic counters |
Commands
cargo fuzz build and cargo fuzz run must be executed with fuzz/
(or deeper) as the working directory so rustup selects the pinned
nightly toolchain — the detached runner handles that itself.
# build (nightly, pinned by rust-toolchain.toml inside fuzz/; run from fuzz/)
cargo fuzz build
# agent sessions: detached campaign (never foreground; CWD-independent)
FUZZ_RUNTIME_SECS=600 fuzz/run-detached.sh datagram_codec -max_len=65536
FUZZ_RUNTIME_SECS=600 fuzz/run-detached.sh params_parse -dict=json.dict -use_value_profile=1
FUZZ_RUNTIME_SECS=600 fuzz/run-detached.sh session_pumps -max_len=4096 -use_value_profile=1
# corpus replay through the invariants (stable toolchain, no nightly)
cargo test --manifest-path fuzz/shared/Cargo.toml
# coverage
cargo fuzz coverage <target>
The fuzz workspace is excluded from the main workspace and from the
published package (exclude in the root Cargo.toml); it pins its own
nightly toolchain via rust-toolchain.toml and does not affect the
crate's stable MSRV.