kern 1.0.3

Security hardening, in-kernel virtio, formatter and go-parity stdlib

A security release on the 1.0 line2,274 tests431 stdlib modules

Capability bypass fixes

E0404 waived for a library's call to an authority builtin and for a Cap-taking declaration of a gated name; E0407 switched off by a user function named __cap_trusted_src or by compiler-source trust inferred from paths; the checker's own bookkeeping writable by declaring a function of the same name.

Ambient authority closed

Nine host-state functions without a capability now take Cap<Container>; the microVM runner's entry hook (std.runtime.vm_dispatch) and the netlink builders are import-restricted (E0408).

Container state hardened

The state root was world-readable (0755, now 0700); a container's env or image could plant a field in state.json (now escaped); path traversal out of the container and network state root is closed.

std.ai removed

(gave package code stdlib provenance; import kern_ai.* instead).

In-kernel virtio datapath

Vhost-net rings through ioeventfd and irqfd; the runner process is on neither the data path nor the interrupt path.

VM runner self-containment

User/mount/pid/IPC/UTS/net namespaces, a per-VM subordinate uid, chroot to an empty directory, all before KVM_CREATE_VM.

Installer release tag signature verification

SSH-signed tag check with a pinned key; a non-v* ref requires KERN_ALLOW_UNSIGNED=1.

Go-parity wave

A safe-by-construction formatter (kern fmt) with comment preservation and a round-trip regression gate; 12 new stdlib modules (std.csv, std.flag, std.tabwriter, std.base32, std.glob, std.mime, std.strconv, std.template, std.crc, std.mail, std.xml, time.parse_iso); generic return recovery for Container<T>; generic typed channel/mutex API in std.sync (TypedChannel<T>, Mutex<T>, RwLock<T>); per-instance CPU pressure through /v1/utilisation (UR-106); a frozen compat corpus enforcing the 1.x compatibility promise; a normative spec with formal-proof limits surfaced; the edition "2027" mechanism (W0005 to E0309, W0003 to E0332).

By the numbers

TCB 42,174. 2,274 tests (1,601 conformance + 206 compat + 467 negative). 431 stdlib modules (308 core + 123 in 10 bundled packages), 4,824 public functions. 61K-line self-hosted compiler (LLVM + native ARM64), 66K-line C runtime.