Microsoft's ML flagged the rc.1 release binaries. The decisive evidence is that
the SAME sha256 went from 0/62 clean to Microsoft-detected in about an hour with
no byte change, so the verdict lives partly in scanner-side state and no code
change can promise a clean result. What code CAN do is stop shipping things that
have no business in a release artifact, which is worth doing on its own merits
and incidentally widens the classifier margin. Every claim below is verified
against a built binary by the new gate, not by reading source.
Executable stack (the worst of the findings). vendored/nomic/code_vectors_blob.S
is the only assembly in the build and carried no .note.GNU-stack. An unannotated
object makes ld assume the worst for the whole link, so EVERY Linux release we
have ever shipped had GNU_STACK RWE. Adds the note (cause) plus ELF-only
-Wl,-z,noexecstack (outcome); the gate fails the release if it returns.
Test seams are now opt-in, never opt-out. TEST_SEAMS=1 defines
CBM_ENABLE_TEST_SEAMS; without it the crash-orphan probe -- which forks a child
that ignores SIGTERM and loops forever, then writes its pid to a caller-supplied
path -- and the lease-ownership marker compile to trivial stubs, so call sites are
untouched and the binary holds no fork, no signal handler and no env-var string.
Opt-IN is the point: forgetting the flag yields a clean binary rather than a leaky
one. scripts/test.sh requests it in the leg that consumes it, and
tests/test_worker_watchdog.sh now asserts the capability up front instead of
dying later with an opaque "Killed: 9".
The daemon's background version check is gone. It spawned curl against
api.github.com/repos/.../releases/latest on the first eligible session of every
run to say "a newer version exists" -- a release URL and an outbound request in
every shipped binary, for something the install scripts already report. The
INJECTABLE SEAM survives: update_ops is still honoured, the fakes in
tests/test_daemon_application.c still cover notice/ownership/cancellation/replay,
and with no provider application_update_subscribe_locked returns early so no
generation ever starts. "No network request by default" is now structural.
Dead capability out of release builds. The tar.gz/zip extraction block
(gzip_decompress through cbm_extract_binary_from_zip, plus its cli.h
declarations) moves under CBM_CLI_ENABLE_TEST_API -- verified self-contained, zero
uses of any helper outside it, only callers the excluded updater and
tests/test_cli.c. Downloading an archive, decompressing it, picking an executable
out of it and marking it executable is the canonical dropper composite; it is now
absent rather than merely unreachable. SQLite is built with
-DSQLITE_OMIT_LOAD_EXTENSION (no caller of load_extension anywhere in src/ or
internal/), removing that API surface and part of the dlopen/dlsym surface.
Temp files and environment scanning (S2/S3). Predictable paths in mcp.c,
artifact.c and diagnostics.c are created privately and exclusively and written
through the returned descriptor; pass_envscan.c no longer descends symlinked
directories out of the project root, and its fixed 512-byte path buffers no
longer truncate into pointer arithmetic that could land outside the buffer.
Build-time entropy. mimalloc's version banner baked __DATE__/__TIME__ into every
binary, so two builds of identical source seconds apart could never share a hash
and no release could inherit a false-positive determination made about its
predecessor. Local patch removes it (marked to survive refreshes), -Wdate-time
makes any future use a build error, and -Wl,--no-insert-timestamp stops the PE
header carrying the link clock.
scripts/ci/check-binary-composition.sh is the proof that each removal stays
removed, wired into package-release.sh after strip so the local artifact-flow
smoke enforces exactly what CI does. It asserts absences plus a CANARY string, so
handing it a compressed, stubbed or empty file fails instead of passing
vacuously, and a missing tool is a hard error -- a skipped assertion must never
look like a satisfied one.
Two build-system traps found by that gate, both of which had silently defeated a
fix: the product binary is compiled in one shot from sources, so a flag flip did
not rebuild it (now tracked by a .build-config stamp that also removes the
binary, making it independent of mtime granularity); and prod_sqlite3.o /
prod_mimalloc.o depended on a single named source, so SQLITE_OMIT_LOAD_EXTENSION
and the mimalloc patch BOTH compiled to nothing on the first incremental build.
Source review would have called them done.
Deliberately NOT changed. Three seams stay in release artifacts because
scripts/smoke-test.sh runs against the real artifact and needs them:
CBM_TEST_CRASH_ON and CBM_TEST_HANG_ON inject the faults that prove supervisor
recovery, and CBM_TEST_WINDOWS_USER_PATH_RUN_ID is what keeps the PATH smoke from
writing the tester's actual PATH. The gate treats those as an allowlist, so a
NOVEL seam still fails. The true no-UI standard build is deferred rather than
rushed: src/ui/* is in PROD_SRCS and four files outside src/ui reference UI
symbols, including the daemon that serves the UI, so that assertion reports
instead of failing until the split lands -- a gate everyone knows is red teaches
people to ignore gates.
No grammar is removed. ObjectScript accounts for essentially all binary growth
since the last provably-clean release (+21.4MB rodata, +1.1MB text from two
four-line shims), which made it the obvious ablation candidate, but a dry run
performed twelve real Defender endpoint scans across standard/UI and amd64/arm64
with ObjectScript, the daemon and the expanded hooks all present and every scan
was clean. Nothing there is a deterministic trigger, so cutting a
community-contributed language would spend a real feature on unproven margin.
Lean is not a candidate either: at 99.6MB of source it is by far the largest
grammar, but it shipped in v0.9.0 which scanned 20/20 clean, so removing it would
produce a novel unscanned profile instead of restoring a known-good one.
Signed-off-by: Martin Vogel <martin.vogel.tech@gmail.com>
Martin Vogel
1f674c805e