## What changed
Wire existing sandbox integrity checks into local command preparation, exec-server process preparation, and sandboxed filesystem helper and file-open operations. Make execution request preparation asynchronous so callers can await the checks.
The checks remain observational: failures and timeouts do not prevent command execution.
## Testing
Add regression tests that launch a real command after checker preparation fails or exceeds its timeout, verifying successful output and exit status.
GitOrigin-RevId: a82399f8aeb8b08f9965e6121b4c7f460552af3f
## What changed
Move `SandboxOverride` into the shared protocol and carry the controller's selection through tool attempts, execution requests, and exec-server process and filesystem sandbox preparation. Include it as `sandboxOverride` in filesystem sandbox contexts for observation without granting broader permissions or altering sandbox commands.
Default missing values to `NoOverride` and omit that value when serializing to preserve compatibility with existing requests.
## Testing
Extend tests to cover override propagation, wire round-trips for all three variants, and deserialization of requests without `sandboxOverride`.
GitOrigin-RevId: 2f438cf4aef1134e3149959d14aa731682168ae5
## Why
Private IP destinations always bypassed inherited upstream proxies, preventing their use for private networks reachable through an upstream VPN proxy.
## What changed
- Add `codex exec-server --proxy-private-ips-via-upstream`, also configurable with `CODEX_EXEC_SERVER_PROXY_PRIVATE_IPS_VIA_UPSTREAM=true`. The setting defaults to disabled.
- Allow permitted RFC 1918, carrier-grade NAT, and IPv6 unique-local destinations to use an applicable upstream proxy. Loopback and link-local destinations retain direct routing, and destination access policy still applies.
- Keep connections direct when no valid upstream proxy applies or `allow_upstream_proxy=false`. Errors after selecting an upstream proxy do not trigger a direct retry.
- Rename `ExecServerRuntimePaths` to `ExecServerRuntimeOptions` and carry the routing setting from executor startup into the managed network proxy.
## Testing
Add routing coverage for private address ranges, special-use addresses, and public targets with the option enabled and disabled. Verify that HTTP and CONNECT requests still enforce destination allowlists and denylists, and update the CLI help snapshot.
GitOrigin-RevId: b7c9cc7da0e0f545694a6521b74c9b36b7b92769
## Why
When a container denies fresh `/proc` mounts, the existing sandbox fallback retains the caller's `/proc` while creating a new PID namespace. Process IDs inside the sandbox can then differ from those exposed by `/proc`, breaking process lookups.
## What changed
- Add `codex exec-server --linux-sandbox-pid-namespace=inherit` to reuse the caller's PID namespace and `/proc` for both process and filesystem helpers. Repository config and command environment variables cannot enable it.
- Keep `isolate` as the default, preserving the existing mount fallback and compatibility with older helpers. Inheritance requires an updated helper and omits `--unshare-pid` and `--as-pid-1`.
- Preserve other sandbox restrictions. With `:minimal`, bind the inherited `/proc` read-only with its container masks and apply explicit filesystem denials afterward.
Inheritance is intended for dedicated environments: it allows sandboxed commands to signal other same-UID processes, including the executor.
## Testing
Add unit and integration coverage for namespace flags, denied proc mounts, consistent process IDs, retained sandbox restrictions, and startup-only selection across process and filesystem helpers.
GitOrigin-RevId: dd13f2b9286d7edcf366b3a42a455f4d78daaf27
## Why
Local `apply_patch` permission checks can treat a macOS system alias and its canonical spelling as different locations, sending writes covered by temporary-directory grants for unnecessary approval.
## What changed
- Normalize trusted top-level aliases in local policy roots and patch targets, reusing a prepared matcher for permission requests and patch safety checks.
- Share alias normalization with Seatbelt and the macOS executor sandbox while preserving mutable symlinks and missing descendants.
- Preserve read-only and deny precedence, protected metadata restrictions, and remote URI matching. Propagate normalization failures from fallible permission checks.
## Testing
Add macOS regressions for multi-file patches with missing parent directories through both direct `apply_patch` calls and shell interception, asserting automatic approval and file contents. Add unit coverage for alias restriction precedence, mutable symlink preservation, missing descendants, and remote permission isolation.
GitOrigin-RevId: 0822ff951eaab728cb1ad91281745fa1b8809f15
## What changed
- Add `ProcessMode::NewSession`, null stdin, and opt-in Linux parent-death termination to the shared child command API.
- Replace `DescriptorPolicy::StdioOnly` with `Explicit` and add `preserve_fds` to allow selected inheritable Unix descriptors alongside stdio. Preserve descriptor numbers without duplicating or closing the parent's descriptors, keeping POSIX record locks intact.
- Support session creation and preserved descriptors in the native macOS backend, with a compatible fallback for high descriptor numbers rejected by native file actions.
## Testing
Add regression coverage for process groups and sessions, descriptor preservation across native and executable-text launches, the last descriptor slot below the file limit, and retention of parent record locks.
GitOrigin-RevId: 29ecd859d3b673da6ae6412cc06a32fa10d11346
## Why
On Windows, MXC needs `SystemDrive` to resolve platform directories and
`LOCALAPPDATA` to create the sandboxed helper process. The helper environment
filter previously dropped both variables.
## What changed
Allow `SystemDrive` and `LOCALAPPDATA` alongside `PATH` in the Windows helper
environment, using case-insensitive name matching.
## Testing
Extend the Windows environment-filtering test to verify that mixed-case runtime
variable names are preserved while `PATH_INJECTION` and `OPENAI_API_KEY` remain
excluded.
GitOrigin-RevId: bab242dd59da59ac6e7f428436e1c139aadadfdd
## Why
Filesystem helpers use a `pre_exec` callback to close inherited descriptors on macOS, forcing a fork before execution. Native spawning needs to preserve that isolation and support the socket used for file descriptor transfer.
## What changed
- Launch filesystem helpers through `codex_utils_pty::Command`, using `posix_spawn` with `POSIX_SPAWN_CLOEXEC_DEFAULT` on macOS and returning native launch errors without a fork fallback.
- Extend the shared command wrapper with explicit descriptor and fallback policies, socket-backed stdin, and custom `argv[0]` support.
- Add `Child::wait_with_output` to drain stdout and stderr concurrently, retain kill-on-drop behavior on cancellation, and keep output pipes open until the child exits.
## Testing
Add regression tests for fork-free sandboxed reads, writes, and file descriptor transfers; sandbox denial of outside paths and symlink escapes; descriptor isolation; bidirectional socket stdin; custom `argv[0]`; executable-format errors; and output-pipe lifetimes.
GitOrigin-RevId: d49c00787f30ec0bc196f9e066a0770fc8151152
## What changed
- Remove the private-desktop opt-out from elevated and unelevated Windows sandbox launches.
- Remove `windows.sandbox_private_desktop` and its managed requirement and API fields. Warn users to remove the obsolete setting.
- Require a private desktop name when launching through the Windows sandbox wrapper and command runner.
## Testing
Add coverage for the obsolete-setting migration warning and update wrapper tests to verify a live private desktop is passed and a missing desktop name is rejected.
GitOrigin-RevId: c7135f8d211aac8d812180691c2c1e433d77cde4
## Why
Removing the selected working directory can prevent filesystem sandbox helpers from launching, even when the requested absolute paths remain accessible. Permission rules must stay anchored to the selected directory while those operations continue.
## What changed
- Require a policy `cwd` in `FileSystemSandboxContext` and launch filesystem helpers from the filesystem root while preserving the policy directory and workspace roots.
- Carry explicit `policyContext` in filesystem RPCs, preserving legacy wire fields and resolving omitted directories from older clients at executor ingress.
- Keep permission paths as executor file URIs and validate host compatibility where they are enforced.
- Bind Windows relative denial globs to the policy directory before changing the helper's launch directory, preserving home-relative patterns.
## Testing
Add regression coverage for `apply_patch` after working-directory removal, legacy RPC directory fallbacks, cross-platform permission URI transport, and Windows relative read denials. The patch regression verifies that an allowed file is updated while an explicitly denied file remains unreadable and unchanged.
GitOrigin-RevId: b0f4db722b27cb72ec129fc297c85732afac11f7
## Why
MXC is a sandbox implementation, not a restricted-token sandbox level. Executor requests need to represent that choice separately from `WindowsSandboxLevel`.
## What changed
- Introduce `WindowsSandboxSelection` for executor sandbox contexts and remove `Mxc` from `WindowsSandboxLevel`.
- Preserve the `windowsSandboxLevel` wire field and its serialized values for compatibility.
- Share sandbox selection between executor process launches and filesystem helpers, and use the new selection in capability discovery and skill reads.
- Disable Windows sandbox selection for executor paths that do not use Windows path conventions.
## Testing
Extend coverage for MXC wire serialization, Windows skill-read sandbox checks, and capability discovery with distinct permissions. Exercise remote filesystem write restrictions with both restricted-token and MXC sandboxes, including rejection when native MXC is unavailable.
GitOrigin-RevId: 266211377bcb138a0dc75861e9ff2225fa37a53d
## What changed
- Add explicit MXC backend selection and carry its identity through exec-server process reporting and sandbox violation classification.
- Launch MXC through the Codex executable with the effective permission profile and command environment.
- Reject exec-server MXC requests when native MXC is unavailable or when they request a TTY, an `arg0` override, or managed networking. Reject private desktop isolation during MXC preparation.
- Allow an explicitly empty child environment and avoid exposing request payload values in launcher decode errors.
## Testing
Add coverage for sandbox selection and unsupported-request rejection, plus Windows RPC tests for stdin writes and temporary-directory permissions derived from the command environment. Native MXC tests skip when MXC is unavailable.
GitOrigin-RevId: 3626ff0f9ad7f9b812ce09b68c31ea9a5a9c72b1
## What changed
Add tracing spans for `AGENTS.md` discovery and loading, local file reads and metadata lookups, and filesystem sandbox request preparation and execution. Record the instruction byte limit, whether file operations use the sandbox, and the permission entry count during sandbox preparation, while skipping automatic argument capture.
GitOrigin-RevId: a6aab1cbac975f8042ce48d6a238c48816f7bd77
## Why
Preparing a filesystem sandbox could synchronously probe unrelated permission
roots on the executor runtime thread and repeatedly resolve the same filesystem
aliases while deriving writable roots.
## What changed
- On Linux, leave permission-root alias resolution to the sandbox helper.
- Filter effective permission entries once and cache their resolved paths for
writable-root and read-only carveout construction.
- Return early when the policy has no effective writable entries.
GitOrigin-RevId: 305364173ca55f967c1701aad94d2374f78999d3
## What changed
- Add the macOS-only `allow_symlinked_codex_home` user setting. When enabled in the execution host's `$CODEX_HOME/config.toml`, writable roots at or beneath that home may traverse symlinks.
- Keep the exception disabled by default and prevent project config, command-line overrides, and ignored user config from enabling it. Other writable roots remain subject to symlink checks.
- Propagate the resolved setting through local, interactive, and exec-server sandbox paths, including `CODEX_HOME` aliases.
- Explain the opt-out in symlink rejection errors, including that it trusts targets outside `CODEX_HOME` and targets that change between commands.
## Testing
- Add macOS coverage for shell commands, patches, filesystem helpers, process execution, and interactive startup with enabled, disabled, aliased, and out-of-scope homes.
GitOrigin-RevId: 99fcdf611200c9e1b7713cf06f7fdea5bfa7f089
## What changed
- Pass the selected executor's `PathUri` through user command approval requests instead of converting the working directory to a host-native path.
- Make native-path permission helpers explicitly local and require executor-aware permission transforms to receive a `FileSystemSandboxPolicyContext`.
- Cover approved remote commands to verify that the approval request reports the selected remote working directory and execution resumes after approval.
GitOrigin-RevId: 0aa3042f2d7594af6c7d0abf31d7f99cf67d5556
## Why
Windows filesystem operations can complete while their helper process remains
alive, and elevated sandbox processes must not survive a disconnected control
pipe.
## What changed
- Read newline-delimited filesystem helper responses without imposing an
operation deadline, then bound the time spent reaping the helper.
- Drain helper stderr concurrently, retain a bounded diagnostic on failure, and
kill helpers that do not exit after responding.
- Terminate the elevated runner's job or process when its input pipe closes or
fails.
## Testing
Added coverage for delayed responses, noisy stderr, stuck helpers, duplicated
file handles, and termination of elevated descendants after a control-pipe
disconnect.
GitOrigin-RevId: c0d3d5d76e13318de17638df4db71fcfb9a7397f
## Why
Filesystem permission paths can use a convention that differs from the host
running Codex. Converting them immediately to native absolute paths can change
the meaning of ambiguous paths such as `/C:/secret` or Windows UNC paths.
## What changed
- Store literal filesystem permission paths as `PathUri` values through the
runtime policy and execution protocol.
- Keep legacy string-based serialization at explicit protocol boundaries and
reject conversions that cannot be represented losslessly.
- Encode native paths as opaque URIs when a normal file URI would imply the
wrong path convention.
## Testing
Added coverage for cross-platform and ambiguous path round trips, UNC path
variants, permission-profile serialization, and deny-policy enforcement.
GitOrigin-RevId: 5247713796d1f2bb4e02f94eb9fc82d4698060f0
## Why
Filesystem helpers only need access to their own executables. Granting access to
the containing directories also makes unrelated sibling files readable.
## What changed
- Allow filesystem helpers to read the Codex and Linux sandbox executables
directly instead of their parent directories.
- Give macOS filesystem helpers a narrower Seatbelt profile that omits the
normal process sandbox's `/Applications` read access.
- Preserve the existing platform defaults for normal sandboxed processes.
## Testing
Add unit and integration coverage for direct and symlinked sibling-file access,
sandboxed copies, allowed workspace reads, and the macOS-specific Seatbelt
profiles.
GitOrigin-RevId: 9380c6868a695bdf2275baa74bd5e8a30a64ba1b
## What changed
Implement `From<AbsolutePathBuf>` for `FileSystemPath` and use the conversion
when constructing concrete filesystem permission paths.
GitOrigin-RevId: 244bcbd0c3f76cd87cc1240458fcac6c9ef0a8e3
## Why
Streaming reads previously rejected requests that used a platform filesystem
sandbox.
## What changed
- Open streamed files in the sandbox helper and return the open file to the
exec-server by passing a file descriptor on Unix or duplicating a file handle
on Windows.
- Advertise support through the `sandboxedFileStreaming` environment capability.
- Preserve close-on-exec behavior for transferred descriptors, including the
required inherited-descriptor cleanup on macOS.
## Testing
- Cover bounded sandboxed streams, continued reads after path replacement, and
rejection of symlink escapes outside readable roots.
GitOrigin-RevId: 677b2444b74e834b78b87a8554bc119c1c6e08b2
## Why
Cross-platform remote `apply_patch` calls were rejected when filesystem writes
were restricted because patch verification and writes could not be safely
performed against executor files.
## What changed
- Route intercepted and direct remote patches through the executor-managed
filesystem sandbox, including the configured workspace roots.
- Select the restricted-token sandbox for Windows executor paths when no
Windows sandbox level was configured.
- Fail closed when an executor cannot enforce the requested sandbox, and treat
executor-managed access failures as sandbox denials so approval can retry the
patch without sandboxing.
## Testing
- Cover sandboxed remote patches, denied writes, approval retries, Windows
sandbox selection, and executor filesystem enforcement.
GitOrigin-RevId: caddeed0b266c456a689080a14a3a58e2bd7887c
## Why
Model-reachable child processes should not inherit Codex launch context.
## What changed
- Treat `OPENAI_FEDERATION_RULE_ID` and `OPENAI_IDENTITY_TOKEN_FILE` as non-inheritable environment variables, with case-insensitive matching.
- Remove them after shell environment policy overrides and before spawning commands across execution, MCP, hooks, Git helpers, and remote helper processes.
## Testing
- Cover inherited and explicitly configured variants, including mixed-case names.
- Verify the variables are absent from real child environments and app-server command and process execution.
GitOrigin-RevId: 2535527893985fef0995617f4c5b2462bea7c136
## What changed
- Pass the canonical `PermissionProfile` through execution requests, sandbox
selection, escalation, and the exec server instead of carrying separate
derived filesystem and network policies.
- Derive runtime sandbox policies from the effective profile at their points of
use, including after applying additional permissions.
- Update sandbox and escalation tests to inspect policies through the profile.
GitOrigin-RevId: 695b82ea94f5289516b0933bb23074cb2dcce8ac
## Why
Default read-only protections for project metadata should apply when paths such
as `.git`, `.agents`, and `.codex` exist, without causing sandbox setup to
materialize missing paths as ACL targets.
## What changed
- Add an optional `missing_path_behavior` to filesystem sandbox entries and
mark default project-metadata protections with `skip`.
- Preserve the behavior through permission transforms and exec/MCP protocol
serialization while keeping existing path wire variants stable.
- Ignore skip-missing entries when projecting configuration or Windows sandbox
overrides, while retaining explicit metadata carveouts.
## Testing
- Cover protocol round trips for path and special-path entries.
- Verify default metadata protections and Windows explicit carveout handling.
GitOrigin-RevId: 6df13dadacdd131c44aab9f15a967c81051355c1
## What changed
- Pass configured workspace roots from core to the exec server so filesystem and process sandbox permissions are materialized against the intended roots.
- Preserve an explicitly empty workspace-root list instead of treating the sandbox working directory as an implicit root.
- Initialize filesystem sandbox contexts with their working directory as the default workspace root.
## Testing
- Add end-to-end coverage for patch and command writes inside and outside workspace roots.
- Verify remote filesystem and process sandboxes do not grant access through an empty workspace-root list.
GitOrigin-RevId: 6684c8f7de50970b45a29e2a6323df954c96f9f6
Filesystem helper requests currently turn symbolic `:workspace_roots`
permissions into a sandbox policy before applying the workspace roots
from the filesystem sandbox context. This can accidentally broaden
filesystem access to the cwd instead of limiting it to the selected
workspace roots.
Materialize project-root permissions using the context workspace roots
before deriving the filesystem sandbox policy. The same converted roots
are then reused when constructing the sandbox command, keeping policy
enforcement and process setup aligned.
Adds a remote filesystem integration test that verifies a file inside
the selected workspace root is readable while a sibling under the cwd is
denied.
## Validation
- `just test -p codex-exec-server
remote_read_file_materializes_environment_workspace_roots` (macOS,
outside the outer Seatbelt sandbox)
## Why
The app-server and exec-server expose separate JSON-RPC APIs, but
exec-server currently sources its serialized protocol and envelope types
through app-server-oriented code. Giving each API an explicit owner
makes the crate boundary legible without introducing shared generic
envelopes.
## What changed
- Added `codex-exec-server-protocol` to own exec DTOs, process IDs, and
JSON-RPC envelopes.
- Updated exec-server clients, transports, handlers, and tests to use
the new crate.
- Exposed app-server's existing JSON-RPC types through a public `rpc`
module while retaining root re-exports.
- Preserved existing wire shapes, including exec `PathUri` behavior.
## Stack
This is PR 1 of 6. Next: [PR
#29721](https://github.com/openai/codex/pull/29721), which moves auth
mode below the app wire boundary.
## Validation
- Exec-server protocol and server coverage passed in the focused
protocol test runs.
- App-server protocol schema fixtures passed.
## Why
Filesystem helpers intentionally run with a minimal environment that
excludes proxy variables. After filesystem operations started using the
Windows sandbox wrapper, the wrapper derived an empty proxy
configuration from that helper environment and compared it with the
persistent sandbox setup marker. When the marker contained proxy ports,
every filesystem operation appeared to require a firewall update, which
could launch elevated setup, show a UAC or loader dialog, and fail
operations such as `apply_patch` with error 1223.
Filesystem helpers do not use network access, so they should preserve
the proxy/firewall state established by normal sandboxed process
launches.
## What changed
- Add an explicit Windows sandbox proxy-settings mode for reconciling or
preserving persistent proxy state.
- Use preserve mode for filesystem helpers while normal process launches
continue to reconcile proxy settings from their environment.
- Carry the selected proxy state consistently through setup validation,
elevated setup, and non-elevated ACL refreshes.
- Cover wrapper argument propagation and marker-derived proxy
preservation.
## Validation
- `cargo build -p codex-cli --bin codex`
- `just test -p codex-windows-sandbox
preserving_proxy_settings_uses_the_existing_marker`
- `just test -p codex-windows-sandbox windows_wrapper_args_round_trip`
- `just test -p codex-windows-sandbox
setup_request_prefers_explicit_proxy_settings`
- `just test -p codex-sandboxing transform_for_direct_spawn_windows`
- `just test -p codex-exec-server fs_sandbox::tests`
- Ran the same sandboxed `fs/writeFile` reproduction against published
`0.142.0-alpha.6` and the new CLI. The published CLI launched elevated
setup and failed with `ShellExecuteExW ... 1223`; the new CLI completed
without elevation.
Related to #28359.
## Why
Managed network configures commands to use local HTTP and SOCKS proxies.
For commands delegated to the exec server, the proxy environment and the
sandbox policy were prepared separately. On macOS, that meant a command
could receive `HTTPS_PROXY=http://127.0.0.1:43123` while Seatbelt still
denied access to port `43123`.
## What changed
`NetworkProxy` now prepares the command environment and sandbox context
together from the same runtime snapshot:
```text
Prepared managed network
├── command environment: HTTPS_PROXY=http://127.0.0.1:43123
└── sandbox context: allow outbound to 127.0.0.1:43123
```
That context travels with remote exec requests. The exec server
preserves the managed proxy and CA environment, and macOS Seatbelt
allows only the prepared loopback proxy ports without enabling broad
network access or local binding.
The protocol field is optional and the existing enforcement flag remains
in place, preserving compatibility with callers that do not send the new
context.
## Why
Prepare network approval scoping to distinguish execution environments
without changing behavior yet.
## What changed
- Add optional environment IDs to network policy requests.
- Add optional network environment IDs to exec and sandbox request
structs.
- Thread default None values through existing construction points.
- Fix stale constructor call sites that caused the CI compile failures.
## Not included
- Per-environment proxy listeners.
- Network approval cache or prompt behavior changes.
- Ambiguous request attribution handling.
Those behavior changes moved to stacked follow-up #28899.
## Validation
- just fmt
- CI will run tests and clippy
## Why
It should be possible for app-server to handle "foreign" OS paths in
unified_exec working directories, allowing e.g. a Linux app-server to
run processes on e.g. a Windows exec-server.
## What
Convert the core unified_exec cwd values to use `PathUri`.
Adds fallible path conversion in several places to try to minimize the
scope of this change. The only time this change suppresses errors from
converting `PathUri` to an `AbsolutePathBuf` is when the turn is
configured with no sandboxing at all to allow us to make progress
testing without sandboxing.
Future changes to apply_patch and sandboxing will clean up these error
paths.
A tool's cwd is resolved from joining a model-provided workdir to the
environment's cwd. When using `AbsolutePathBuf::join()`, an
absolute-path workdir would overwrite the environment's cwd and we would
resolve permissions/sandboxing against the model-provided path. This
change extends `PathUri::join()` to also treat an absolute rhs as an
override of the base/lhs.
This also removes some coverage from the remove_env_windows tests until
a follow-up converts foreign paths in command exec events correctly.
## Breaking Changes
When using `AbsolutePathBuf::join()` for workdir resolution, we ended up
resolving tilde-prefixed paths against the app-server's `$HOME`, e.g.
`~/foo/bar` becomes `/home/anp/foo/bar`. It's difficult to do this with
`PathUri` joining, so after offline discussion this PR no longer
implements it.
A quick check of some power users' rollouts suggests that models don't
actually generate home-prefixed absolute working directories for their
spawns, so this shouldn't have any real blast radius.
## Why
This is the final PR in the Windows fs-helper sandbox stack and contains
the actual bug fix.
The exec-server filesystem helper is a direct-spawn path: it asks
`SandboxManager` for a `SandboxExecRequest`, then launches the returned
argv itself. That works on macOS and Linux because the transformed argv
is already a self-contained sandbox wrapper. On Windows, the transformed
request carried `WindowsRestrictedToken` metadata, but the direct-spawn
fs-helper runner still launched the helper argv directly.
That means Windows filesystem built-ins backed by the fs-helper could
run with the parent Codex process permissions instead of the configured
Windows sandbox. This PR makes the direct-spawn transform produce a
self-contained Windows wrapper argv before fs-helper launches it.
## What Changed
- Added `SandboxManager::transform_for_direct_spawn()` for callers that
launch the returned argv themselves.
- Wrapped Windows restricted-token direct-spawn requests with `codex.exe
--run-as-windows-sandbox` and then marked the outer request as
unsandboxed, matching the macOS/Linux wrapper argv shape.
- Updated `exec-server/src/fs_sandbox.rs` to use the direct-spawn
transform for fs-helper launches.
- Materialized the inner `codex.exe --codex-run-as-fs-helper` executable
into `.sandbox-bin` so the sandboxed user can run it.
- Carried runtime workspace roots through `FileSystemSandboxContext` as
`PathUri` values so `:workspace_roots` policies resolve correctly
without sending native client paths over exec-server JSON.
- Preserved wrapper setup identity environment needed by Windows sandbox
setup without changing the serialized inner helper environment.
## Verification
- `just bazel-lock-update`
- `just bazel-lock-check`
- `just test -p codex-sandboxing transform_for_direct_spawn_windows`
- `just test -p codex-exec-server fs_sandbox::tests`
- `just fix -p codex-windows-sandbox -p codex-sandboxing -p
codex-exec-server -p codex-core -p codex-file-system`
Local note: `just fmt` completed Rust formatting, but this workstation
still fails the non-Rust formatter phases because uv cannot open its
cache and the local buildifier/dotslash path is missing.
## Why
Ensure a consistent string format when exposing path conversion errors
to the model.
## What
- Render `PathUriParseError::InvalidFileUriPath` as `'$PATH' is invalid
on '$OS'`.
## Why
Progress towards letting app-server and exec-server run on different
platforms, specifically for sandbox configuration.
## What
- Make the filesystem path containment hierarchy generic, defaulting to
`AbsolutePathBuf` for now.
- Have clients specify `AbsolutePathBuf` or `PathUri` directly where
needed.
- Use `PathUri` throughout exec-server filesystem protocol and trait
boundaries.
- Implement `From` for conversion to path URIs and `TryFrom` for
fallible conversion to absolute paths through the generic type
hierarchy.
## Why
`PathUri::from_abs_path` can fail for absolute paths that do not have a
normal `file:` URI representation, forcing filesystem call sites to
handle a conversion error even though the original path can be preserved
losslessly.
## What
Make `from_abs_path` infallible and migrate its callers. Unrepresentable
paths use `file:///%00/bad/path/<base64>`, encoding Unix bytes or
Windows UTF-16LE; `to_abs_path` validates and decodes that fallback. The
leading encoded null reserves a namespace that cannot collide with a
real Unix or Windows path, and fallback URIs remain opaque to lexical
path operations.
## Validation
Added path-URI coverage for Unix null and non-UTF-8 paths, Windows
device/verbatim and non-Unicode paths, serialization, malformed
fallbacks, opaque lexical operations, invalid native payloads, and
literal `/bad/path` collision resistance.
## Why
Sandbox cwd values can cross app-server and exec-server host boundaries.
They should retain URI semantics until the receiving host validates them
instead of being interpreted early as native paths.
## What
- Carry `PathUri` through filesystem sandbox contexts, sandbox commands,
and transform inputs.
- Convert command and policy cwd once in `SandboxManager::transform`,
then keep launch requests native.
- Preserve sandbox cwd over remote filesystem transport and reject
non-native URIs without fallback.
- Cache paired native/URI turn-environment cwd values during migration,
with immutable access to keep them synchronized.
- Extend existing protocol, forwarding, transform, and core runtime
tests.
## Summary
- preserve macOS `__CF_USER_TEXT_ENCODING` when launching the sandboxed
fs helper
- keep the fs-helper env narrow; this adds only the CoreFoundation
startup var instead of copying the broader MCP stdio baseline
- add focused coverage that the helper keeps that var without admitting
`HOME`
## Diagnosis
The sandboxed fs helper is not launched like a normal child process.
Exec-server rebuilds its environment from an allowlist, then calls
`env_clear()` before re-execing Codex with `--codex-run-as-fs-helper`.
That helper dispatches before the normal Codex startup path and only
needs to boot a small Tokio runtime, read one JSON request from stdin,
perform the direct filesystem operation, and write one JSON response.
The reported macOS hang sampled the helper before Rust main, in
CoreFoundation initialization while resolving the default text encoding:
`_CFStringGetUserDefaultEncoding -> getpwuid_r -> notify_register_check
-> bootstrap_look_up3 -> mach_msg2_trap`. The fs-helper allowlist kept
`PATH` and temp vars for runtime needs, but it dropped macOS
`__CF_USER_TEXT_ENCODING`. Other Codex subprocess launchers that
intentionally build a minimal Unix baseline, such as MCP stdio, already
preserve that variable.
My read is that stripping `__CF_USER_TEXT_ENCODING` forced this internal
helper down CoreFoundation's fallback user-lookup path, and that lookup
intermittently wedged on the affected machine before the helper could
read stdin or touch the target file. Preserving only this macOS startup
variable avoids that fallback without broadening the fs-helper
environment to shell-like vars such as `HOME`, `USER`, locale settings,
terminal settings, or proxy credentials.
Internal Slack thread omitted from the public PR body.
## Validation
- `cd codex-rs && just fmt`
- `git diff --check`
## Summary
- terminate sandbox filesystem helpers when the Tokio child handle is
dropped
## Why
A sandbox filesystem helper can stall during process startup before
reading stdin. If the owning async operation is cancelled or torn down,
the spawned helper should not remain running as an orphaned process.
Setting `kill_on_drop(true)` gives the filesystem helper the cleanup
behavior that Tokio child processes otherwise do not enable by default.
This intentionally does not add a timeout. It does not detect or recover
an active hung file edit while the owning future remains alive. A more
precise startup-health mechanism can be handled separately.
## Validation
- `just test -p codex-exec-server` (186 tests passed; benchmark smoke
passed)
- `just fmt`
- `just fix -p codex-exec-server`
- `git diff --check`
## Summary
- Bump the workspace Rust toolchain from `1.93.0` to `1.95.0` across
Cargo, Bazel, CI, release workflows, devcontainers, and the Codex
environment config.
- Refresh `MODULE.bazel.lock` so the Bazel Rust toolchain artifacts
match the new version.
- Leave purpose-specific toolchains unchanged, including the
`argument-comment-lint` nightly and the upstream `rusty_v8` `1.91.0`
build pin.
- Includes fixes for new lints from `just fix` and a few codex-authored
fixes for lints without a suggestion.
**Summary**
- Add `codex-bwrap`, a standalone `bwrap` binary built from the existing
vendored bubblewrap sources.
- Remove the linked vendored bwrap path from `codex-linux-sandbox`;
runtime now prefers system `bwrap` and falls back to bundled
`codex-resources/bwrap`.
- Add bundled SHA-256 verification with missing/all-zero digest as the
dev-mode skip value, then exec the verified file through
`/proc/self/fd`.
- Keep `launcher.rs` focused on choosing and dispatching the preferred
launcher. Bundled lookup, digest verification, and bundled exec now live
in `linux-sandbox/src/bundled_bwrap.rs`; Bazel runfiles lookup lives in
`linux-sandbox/src/bazel_bwrap.rs`; shared argv/fd exec helpers live in
`linux-sandbox/src/exec_util.rs`.
- Teach Bazel tests to surface the Bazel-built `//codex-rs/bwrap:bwrap`
through `CARGO_BIN_EXE_bwrap`; `codex-linux-sandbox` only honors that
fallback in debug Bazel runfiles environments so release/user runtime
lookup stays tied to `codex-resources/bwrap`.
- Allow `codex-exec-server` filesystem helpers to preserve just the
Bazel bwrap/runfiles variables they need in debug Bazel builds, since
those helpers intentionally rebuild a small environment before spawning
`codex-linux-sandbox`.
- Verify the Bazel bwrap target in Linux release CI with a build-only
check. Running `bwrap --version` is too strong for GitHub runners
because bubblewrap still attempts namespace setup there.
**Verification**
- Latest update: `cargo test -p codex-linux-sandbox`
- Latest update: `just fix -p codex-linux-sandbox`
- `cargo check --target x86_64-unknown-linux-gnu -p codex-linux-sandbox`
could not run locally because this macOS machine does not have
`x86_64-linux-gnu-gcc`; GitHub Linux Bazel CI is expected to cover the
Linux-only modules.
- Earlier in this PR: `cargo test -p codex-bwrap`
- Earlier in this PR: `cargo test -p codex-exec-server`
- Earlier in this PR: `cargo check --release -p codex-exec-server`
- Earlier in this PR: `just fix -p codex-linux-sandbox -p
codex-exec-server`
- Earlier in this PR: `bazel test --nobuild
//codex-rs/linux-sandbox:linux-sandbox-all-test
//codex-rs/core:core-all-test
//codex-rs/exec-server:exec-server-file_system-test
//codex-rs/app-server:app-server-all-test` (analysis completed; Bazel
then refuses to run tests under `--nobuild`)
- Earlier in this PR: `bazel build --nobuild //codex-rs/bwrap:bwrap`
- Prior to this update: `just bazel-lock-update`, `just
bazel-lock-check`, and YAML parse check for
`.github/workflows/bazel.yml`
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/21255).
* #21257
* #21256
* __->__ #21255
## Summary
- Extracted the shared filesystem types and `ExecutorFileSystem` trait
into a new `codex-file-system` crate
- Switched `codex-config` and `codex-git-utils` to depend on that crate
instead of `codex-exec-server`
- Kept `codex-exec-server` re-exporting the same API for existing
callers
## Testing
- Ran `cargo test -p codex-file-system`
- Ran `cargo test -p codex-git-utils`
- Ran `cargo test -p codex-config`
- Ran `cargo test -p codex-exec-server`
- Ran `just fix -p codex-file-system`, `just fix -p codex-git-utils`,
`just fix -p codex-config`, `just fix -p codex-exec-server`
- Ran `just fmt`
- Updated and verified the Bazel module lockfile
## Why
The experimental `PermissionProfile` API had both `:cwd` and
`:project_roots` special filesystem paths, which made the permission
root ambiguous. This PR removes the unstable `current_working_directory`
special path before the permissions API is stabilized, so callers use
`:project_roots` for symbolic project-root access.
## What changed
- Removes `FileSystemSpecialPath::CurrentWorkingDirectory` from protocol
and app-server protocol models, plus regenerated app-server
JSON/TypeScript schemas.
- Replaces internal `:cwd` permission entries with `:project_roots`
entries.
- Keeps the existing cwd-update behavior for legacy-shaped
workspace-write profiles, while removing the deleted
`CurrentWorkingDirectory` case from that compatibility path.
- Keeps `PermissionProfile::workspace_write()` as the reusable symbolic
workspace-write helper, with docs noting that `:project_roots` entries
resolve at enforcement time.
- Updates app-server docs/examples and approval UI labeling to stop
advertising `:cwd` as a permission token.
## Compatibility
Persisted rollout items may contain the old
`{"kind":"current_working_directory"}` tag from earlier experimental
`permissionProfile` snapshots. This PR keeps that tag as a
deserialize-only alias for `ProjectRoots { subpath: None }`, while
continuing to serialize only the new `project_roots` tag.
## Follow-up
This PR intentionally does not introduce an explicit project-root set on
`SessionConfiguration` or runtime sandbox resolution. Today, the
resolver still uses the active cwd as the single implicit project root.
A follow-up should model project roots separately from tool cwd so
`:project_roots` entries can resolve against the configured project
roots, and resolve to no entries when there are no project roots.
## Verification
- `cargo test -p codex-protocol permissions:: --lib`
- `cargo test -p codex-app-server-protocol`
- `cargo test -p codex-sandboxing -p codex-exec-server --lib`
- `cargo test -p codex-core session_configuration_apply_ --lib`
- `cargo test -p codex-app-server
command_exec_permission_profile_project_roots_use_command_cwd --test
all`
- `cargo test -p codex-tui
thread_read_session_state_does_not_reuse_primary_permission_profile
--lib`
- `cargo test -p codex-tui
preset_matching_accepts_workspace_write_with_extra_roots --lib`
- `cargo test -p codex-config --lib`
## Why
This supersedes #19391. During stack repair, GitHub marked #19391 as
merged into a temporary stack branch rather than into `main`, so the
runtime-config change needed a fresh PR.
`PermissionProfile` is now the canonical permissions shape after #19231
because it can distinguish `Managed`, `Disabled`, and `External`
enforcement while also carrying filesystem rules that legacy
`SandboxPolicy` cannot represent cleanly. Core config and session state
still needed to accept profile-backed permissions without forcing every
profile through the strict legacy bridge, which rejected valid runtime
profiles such as direct write roots.
The unrelated CI/test hardening that previously rode along with this PR
has been split into #19683 so this PR stays focused on the permissions
model migration.
## What Changed
- Adds `Permissions.permission_profile` and
`SessionConfiguration.permission_profile` as constrained runtime state,
while keeping `sandbox_policy` as a legacy compatibility projection.
- Introduces profile setters that keep `PermissionProfile`, split
filesystem/network policies, and legacy `SandboxPolicy` projections
synchronized.
- Uses a compatibility projection for requirement checks and legacy
consumers instead of rejecting profiles that cannot round-trip through
`SandboxPolicy` exactly.
- Updates config loading, config overrides, session updates, turn
context plumbing, prompt permission text, sandbox tags, and exec request
construction to carry profile-backed runtime permissions.
- Preserves configured deny-read entries and `glob_scan_max_depth` when
command/session profiles are narrowed.
- Adds `PermissionProfile::read_only()` and
`PermissionProfile::workspace_write()` presets that match legacy
defaults.
## Verification
- `cargo test -p codex-core direct_write_roots`
- `cargo test -p codex-core runtime_roots_to_legacy_projection`
- `cargo test -p codex-app-server
requested_permissions_trust_project_uses_permission_profile_intent`
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/19606).
* #19395
* #19394
* #19393
* #19392
* __->__ #19606
## Why
`ReadOnlyAccess` was a transitional legacy shape on `SandboxPolicy`:
`FullAccess` meant the historical read-only/workspace-write modes could
read the full filesystem, while `Restricted` tried to carry partial
readable roots. The partial-read model now belongs in
`FileSystemSandboxPolicy` and `PermissionProfile`, so keeping it on
`SandboxPolicy` makes every legacy projection reintroduce lossy
read-root bookkeeping and creates unnecessary noise in the rest of the
permissions migration.
This PR makes the legacy policy model narrower and explicit:
`SandboxPolicy::ReadOnly` and `SandboxPolicy::WorkspaceWrite` represent
the old full-read sandbox modes only. Split readable roots, deny-read
globs, and platform-default/minimal read behavior stay in the runtime
permissions model.
## What changed
- Removes `ReadOnlyAccess` from
`codex_protocol::protocol::SandboxPolicy`, including the generated
`access` and `readOnlyAccess` API fields.
- Updates legacy policy/profile conversions so restricted filesystem
reads are represented only by `FileSystemSandboxPolicy` /
`PermissionProfile` entries.
- Keeps app-server v2 compatible with legacy `fullAccess` read-access
payloads by accepting and ignoring that no-op shape, while rejecting
legacy `restricted` read-access payloads instead of silently widening
them to full-read legacy policies.
- Carries Windows sandbox platform-default read behavior with an
explicit override flag instead of depending on
`ReadOnlyAccess::Restricted`.
- Refreshes generated app-server schema/types and updates tests/docs for
the simplified legacy policy shape.
## Verification
- `cargo check -p codex-app-server-protocol --tests`
- `cargo check -p codex-windows-sandbox --tests`
- `cargo test -p codex-app-server-protocol sandbox_policy_`
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/19449).
* #19395
* #19394
* #19393
* #19392
* #19391
* __->__ #19449
## Why
`PermissionProfile` is becoming the canonical permissions abstraction,
but the old shape only carried optional filesystem and network fields.
It could describe allowed access, but not who is responsible for
enforcing it. That made `DangerFullAccess` and `ExternalSandbox` lossy
when profiles were exported, cached, or round-tripped through app-server
APIs.
The important model change is that active permissions are now a disjoint
union over the enforcement mode. Conceptually:
```rust
pub enum PermissionProfile {
Managed {
file_system: FileSystemSandboxPolicy,
network: NetworkSandboxPolicy,
},
Disabled,
External {
network: NetworkSandboxPolicy,
},
}
```
This distinction matters because `Disabled` means Codex should apply no
outer sandbox at all, while `External` means filesystem isolation is
owned by an outside caller. Those are not equivalent to a broad managed
sandbox. For example, macOS cannot nest Seatbelt inside Seatbelt, so an
inner sandbox may require the outer Codex layer to use no sandbox rather
than a permissive one.
## How Existing Modeling Maps
Legacy `SandboxPolicy` remains a boundary projection, but it now maps
into the higher-fidelity profile model:
- `ReadOnly` and `WorkspaceWrite` map to `PermissionProfile::Managed`
with restricted filesystem entries plus the corresponding network
policy.
- `DangerFullAccess` maps to `PermissionProfile::Disabled`, preserving
the “no outer sandbox” intent instead of treating it as a lax managed
sandbox.
- `ExternalSandbox { network_access }` maps to
`PermissionProfile::External { network }`, preserving external
filesystem enforcement while still carrying the active network policy.
- Split runtime policies that legacy `SandboxPolicy` cannot faithfully
express, such as managed unrestricted filesystem plus restricted
network, stay `Managed` instead of being collapsed into
`ExternalSandbox`.
- Per-command/session/turn grants remain partial overlays via
`AdditionalPermissionProfile`; full `PermissionProfile` is reserved for
complete active runtime permissions.
## What Changed
- Change active `PermissionProfile` into a tagged union: `managed`,
`disabled`, and `external`.
- Keep partial permission grants separate with
`AdditionalPermissionProfile` for command/session/turn overlays.
- Represent managed filesystem permissions as either `restricted`
entries or `unrestricted`; `glob_scan_max_depth` is non-zero when
present.
- Preserve old rollout compatibility by accepting the pre-tagged `{
network, file_system }` profile shape during deserialization.
- Preserve fidelity for important edge cases: `DangerFullAccess`
round-trips as `disabled`, `ExternalSandbox` round-trips as `external`,
and managed unrestricted filesystem + restricted network stays managed
instead of being mistaken for external enforcement.
- Preserve configured deny-read entries and bounded glob scan depth when
full profiles are projected back into runtime policies, including
unrestricted replacements that now become `:root = write` plus deny
entries.
- Regenerate the experimental app-server v2 JSON/TypeScript schema and
update the `command/exec` README example for the tagged
`permissionProfile` shape.
## Compatibility
Legacy `SandboxPolicy` remains available at config/API boundaries as the
compatibility projection. Existing rollout lines with the old
`PermissionProfile` shape continue to load. The app-server
`permissionProfile` field is experimental, so its v2 wire shape is
intentionally updated to match the higher-fidelity model.
## Verification
- `just write-app-server-schema`
- `cargo check --tests`
- `cargo test -p codex-protocol permission_profile`
- `cargo test -p codex-protocol
preserving_deny_entries_keeps_unrestricted_policy_enforceable`
- `cargo test -p codex-app-server-protocol
permission_profile_file_system_permissions`
- `cargo test -p codex-app-server-protocol serialize_client_response`
- `cargo test -p codex-core
session_configured_reports_permission_profile_for_external_sandbox`
- `just fix`
- `just fix -p codex-protocol`
- `just fix -p codex-app-server-protocol`
- `just fix -p codex-core`
- `just fix -p codex-app-server`
## Why
This is a cleanup PR for the `PermissionProfile` migration stack. #19016
fixed remote exec-server sandbox contexts so Docker-backed filesystem
requests use a request/container `cwd` instead of leaking the local test
runner `cwd`. That exposed the broader API problem:
`FileSystemSandboxContext::new(SandboxPolicy)` could still reconstruct
filesystem permissions by reading the exec-server process cwd with
`AbsolutePathBuf::current_dir()`.
That made `cwd`-dependent legacy entries, such as `:cwd`,
`:project_roots`, and relative deny globs, depend on ambient process
state instead of the request sandbox `cwd`. As later PRs make
`PermissionProfile` the primary permissions abstraction, sandbox
contexts should be explicit about whether they carry a request `cwd` or
are profile-only. Removing the implicit constructor prevents new call
sites from accidentally rebuilding permissions against the wrong `cwd`.
## What changed
- Removed `FileSystemSandboxContext::new(SandboxPolicy)`.
- Kept production callers on explicit constructors:
`from_legacy_sandbox_policy(..., cwd)`, `from_permission_profile(...)`,
and `from_permission_profile_with_cwd(...)`.
- Updated exec-server test helpers to construct `PermissionProfile`
values directly instead of routing through legacy `SandboxPolicy`
projections.
- Updated the environment regression test to use an explicit restricted
profile with no synthetic `cwd`.
## Verification
- `cargo test -p codex-exec-server`
- `just fix -p codex-exec-server`
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/19046).
* #18288
* #18287
* #18286
* #18285
* #18284
* #18283
* #18282
* #18281
* #18280
* __->__ #19046
## Why
The post-merge `rust-ci-full` run for #18999 still failed the Ubuntu
remote `suite::remote_env` sandboxed filesystem tests. That run checked
out merge commit `ddde50c611e4800cb805f243ed3c50bbafe7d011`, so the arg0
guard lifetime fix was present.
The Docker-backed failure had two remaining pieces:
- The sandboxed filesystem helper needs to execute Codex through the
`codex-linux-sandbox` arg0 alias path. The helper sandbox was only
granting read access to the real Codex executable parent, so the alias
parent also has to be visible inside the helper sandbox.
- The remote-env tests were building sandbox contexts with
`FileSystemSandboxContext::new()`, which captures the local test runner
cwd. In the Docker remote exec-server, that host checkout path does not
exist, so spawning the filesystem helper failed with `No such file or
directory` before the helper could process the request.
## What Changed
- Track all helper runtime read roots instead of a single root.
- Add both the real Codex executable parent and the
`codex-linux-sandbox` alias parent to sandbox readable roots.
- Avoid sending an unused local cwd in remote filesystem sandbox
contexts when the permission profile has no cwd-dependent entries.
- Build the Docker remote-env test sandbox contexts with a cwd path that
exists inside the container.
- Add unit coverage for the alias-parent root and remote sandbox cwd
handling.
## Verification
- `cargo test -p codex-exec-server`
- `cargo test -p codex-core
remote_test_env_sandboxed_read_allows_readable_root`
- `just fix -p codex-exec-server`
- `just fix -p codex-core`
## Why
The exec-server still needs platform sandbox inputs, but the migration
should preserve the `PermissionProfile` that produced them. Keeping only
the derived legacy sandbox map would keep `SandboxPolicy` as the
effective abstraction and would make full-disk vs. restricted profiles
harder to preserve as the permissions stack starts round-tripping
profiles.
`PermissionProfile` entries can also be cwd-sensitive (`:cwd`,
`:project_roots`, relative globs), so the exec-server must carry the
request sandbox cwd instead of resolving those entries against the
long-lived exec-server process cwd.
## What changed
`FileSystemSandboxContext` now carries `permissions: PermissionProfile`
plus an optional `cwd`:
- removed `sandboxPolicy`, `sandboxPolicyCwd`,
`fileSystemSandboxPolicy`, and `additionalPermissions`
- added `permissions` and `cwd`
- kept the platform knobs `windowsSandboxLevel`,
`windowsSandboxPrivateDesktop`, and `useLegacyLandlock`
Core turn and apply-patch paths populate the context from the active
runtime permissions and request cwd. Exec-server derives platform
`SandboxPolicy`/`FileSystemSandboxPolicy` at the filesystem boundary,
adds helper runtime reads there, and rejects cwd-dependent profiles that
arrive without a cwd.
The legacy `FileSystemSandboxContext::new(SandboxPolicy)` constructor
now preserves the old workspace-write conversion semantics for
compatibility tests/callers.
## Verification
- `cargo test -p codex-exec-server`
- `cargo test -p codex-exec-server sandbox_cwd -- --nocapture`
- `cargo test -p codex-exec-server
sandbox_context_new_preserves_legacy_workspace_write_read_only_subpaths
-- --nocapture`
- `cargo test -p codex-core --lib
file_system_sandbox_context_uses_active_attempt -- --nocapture`
## Why
`PermissionProfile` needs stable, canonical file-system semantics before
it can become the primary runtime permissions abstraction. Without a
canonical form, callers have to keep re-deriving legacy sandbox maps and
profile comparisons remain lossy or order-dependent.
## What changed
This adds canonicalization helpers for `FileSystemPermissions` and
`PermissionProfile`, expands special paths into explicit sandbox
entries, and updates permission request/conversion paths to consume
those canonical entries. It also tightens the legacy bridge so root-wide
write profiles with narrower carveouts are not silently projected as
full-disk legacy access.
## Verification
- `cargo test -p codex-protocol
root_write_with_read_only_child_is_not_full_disk_write -- --nocapture`
- `cargo test -p codex-sandboxing permission -- --nocapture`
- `cargo test -p codex-tui permissions -- --nocapture`