CreateNamedPipeW with NULL security attributes does not install a kernel
template: KernelBase builds the documented 5-ACE default SD in user mode
and passes it down; the kernel itself (a raw SD-null create) applies the
token default DACL. Correct the claim in both README sides and the
runner.spec pin comment, and link the MS template documentation.
New objects created without an explicit security descriptor take
their DACL from the token's default DACL, which CreateRestrictedToken
builds from the user's ambient SIDs — none of them a restricting SID.
Confined children therefore failed the write pass-2 check when
creating anonymous pipes (CreatePipe: ERROR_ACCESS_DENIED, surfaced
as Node EPERM), breaking PowerShell pipelines and other CreatePipe
consumers. Merge a full-access write-SID ACE (Everyone under
read-only) into the token default DACL at init via
SetTokenInformation(TokenDefaultDacl).
Named pipes are EXEMPT: their default security descriptor is the
kernel's PUBLIC template (owner/SYSTEM/Admins full, Everyone
read-only), which no token change influences, so libuv's piped stdio
capture stays denied for confined grandchildren — the POC-documented
boundary, now pinned by the runner suite (inherit/ignore OK, pipe
DENIED) and documented in the README pair. The NUL paragraph is
corrected to the measured matrix (Everyone has 0x1201BF on the
device: cmd/node writes land; Set-Content fails at the PS layer).
workspace-write now runs [logon SID, Everyone, orphan]: the two lists differ only by the orphan, and the keep-alive group (logon SID + Everyone) is the single shared invariant. The WMI namespace security check fails in BOTH modes (0x80041003), so CIM/Get-ComputerInfo are unavailable everywhere — the price of closing the C:\\-root tree-creation escape (AU:(AD) + AU:(OI)(CI)(IO)(M)) in workspace-write too. The unused WinLocalSid/WinInteractiveSid/WinAuthenticatedUserSid constants and their ABI-probe prints are removed; the enforcement 'full' claim now stands on a closed NTFS surface. New regression: a C:\\Users\\Public subdirectory write is denied under BOTH modes (the ambient-writable blind spot the review flagged — INTERACTIVE is absent from both lists). FAT-class (non-ACL) targets outside the granted roots remain writable (no security descriptors to intersect) — documented as a legacy residue, warn-only, not engineered around. Docs/design note/PR body updated in both languages (list I/J terminology gone everywhere).
A session that materialized its workspace-write grant and then switched to read-only (or crashed and resumed under read-only) kept a writable workspace for the server lifetime: the standing orphan-SID ACE survived the downgrade and list I still carried the orphan, so the write-restricted pass-2 check granted it. List I is now [logon SID, EVERYONE] only — the standing ACE stays inert under read-only while the unrevoked ACE keeps the re-upgrade free (map hit, no re-propagation). Pinned by the runner's real-token mode-downgrade regression (standing ACE denied under read-only, effective again on re-upgrade), the acl-session mode-switch cycle (nothing under read-only, one materialization on upgrade, no revoke on downgrade), and ConstrainedLanguage pins in both modes.
quoteArg doubles end-of-string backslashes (real CommandLineToArgvW round-trip test; first-token exemption noted); grantWrite merges into the current DACL instead of replacing it, and both grant/revoke hold a LockFileEx per-path lock under GetTempPathW/dsh-acl-locks (koffi crashes on NULL lpOverlapped — a zeroed OVERLAPPED is used); GRANT_MASK gains DELETE|FILE_DELETE_CHILD (never WRITE_DAC/WRITE_OWNER) though the win32 26200 second check only constrains the WRITE bit; failure paths close all handles (CreateProcessAsUserW pipe set, ResumeThread thread/process/job) with stub-api tests; getTempPathW refuses undersized buffers; drainPipe backs off; runner.spec pwshAvailable uses the resolvePwshPath probe; NTSTATUS exit codes mirror bit-exact (verified end-to-end); WinLocalSid JSDoc re-attributed to WinLocalLogonSid. All gates green: 42 passed/2 skipped, typecheck, oxlint, 0 clones, constraints, knip.
Confine Windows command execution through a WRITE_RESTRICTED token whose restricting SIDs carry an orphan-SID write allowlist, ported from https://github.com/huoyaoyuan/windows-acl-restrict-poc (@ 10e4dfb). Every Win32 call is checked and fails closed - the POC silently ran children with the FULL token when CreateRestrictedToken failed.
- @deepseek-ai/dsh-sandbox-windows-acl: koffi primitives verified against the MinGW Windows headers (verify/abi-probe.cpp) plus the confinement runner ([node, runner, --workspace, --temp, --mode, --, argv...]: kill-on-close job, stdio passthrough, exit-code mirroring, windows-acl-run: failure signature, grant revocation). read-only = strict zero grants (NUL device not writable; documented). Windows-only execution: exempted from the Linux coverage lane (windowsOnlyCoverageExclusions).
- @deepseek-ai/dsh-sandbox-local: PLATFORM_CHAINS.win32 filled with the windows-acl runner (full enforcement, ACL denial dialect, runner-failure rules).
- @deepseek-ai/dsh-pwsh-sandbox: sandbox-consuming pwsh executor (call-for-call mirror of dsh-bash-sandbox) over a new argv-level seam in dsh-pwsh-local; per-file coverage complete via the fake-provider spec.
- bundle/base: the Windows platform layer mounts the confined pwsh roster - sandbox/policy/fs-sandbox/permission/approval re-enabled, the POSIX bash stack stays disabled.
Co-authored-by: Huo Yaoyuan <huoyaoyuan@hotmail.com>
