Files
hyperframes/packages/cli/src/server
Miguel Ángel c1c70f44bd fix(cli): signal only processes the OS says own the port (#3307)
* fix(cli): signal only processes the OS says own the port

`/__hyperframes_config` is unauthenticated and the PID it reports is what
`--stop` and `--kill-all` send signals to, so any local process answering on
a scanned port could name an arbitrary PID and have the CLI kill it.
Reproduced with a twenty-line HTTP server on a scanned port self-reporting an
unrelated PID: before this, `--kill-all` killed that process; after it, the
process survives and only the real listener is stopped.

The listening PID now comes from the OS — `lsof`, and `netstat` on Windows,
where the lookup was previously unavailable and the self-reported value was
taken on trust. The response's own PID is used only where the OS lookup
fails, which is also the only case where it is unfalsifiable.

Orphan cleanup moves to the last step before a launch. It reaches outside the
process and kills other people's PIDs, so it must not run for an invocation
that turns out to be a validation error and never starts anything.

* fix(cli): fail closed when the OS cannot confirm who owns a port

Review follow-up.

The two halves of this change picked opposite directions for the same
condition. `isProcessDescendant` fails closed by design; `activeServerOnPort`
fell back to the self-reported PID whenever the OS lookup came back empty —
and that is not only "unsupported platform". `lsof` may be absent (the default
on many slim images), may time out, or may not see a socket owned by another
user. On such a machine every scanned port silently reverted to pre-change
behaviour, with nothing said.

Provenance is now part of the type rather than a convention: `ActiveServer`
carries `pidSource`, so a caller cannot mistake a self-report for the kernel's
answer. `--kill-all` requires `"os"` and skips the rest, naming the ports it
left alone and why. That is the deliberate trade — a blind sweep of a port
range has no evidence beyond an unauthenticated response, so an unconfirmed
PID must not be signalled. Managed previews are unaffected: they stop through
their session record, which proves ownership by process birth identity.

The fallback branch — the one with the security consequence — now has the
coverage it lacked, via an injected lookup matching the seam `testPortOnAllHosts`
and `isProcessDescendant` already use, including a live process that survives
because nothing confirmed it owns the socket.

Also state that `killProcessTree` honours `signal` on POSIX only: Windows
always passes `/F`, deliberately, since taskkill without it posts WM_CLOSE that
a console process may ignore. The caller-side comment claiming Windows cleanup
is a no-op described the code before this change and now says the opposite.
2026-08-18 17:41:46 -04:00
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