## Why
`argument-comment-lint` was green in CI even though the repo still had
many uncommented literal arguments. The main gap was target coverage:
the repo wrapper did not force Cargo to inspect test-only call sites, so
examples like the `latest_session_lookup_params(true, ...)` tests in
`codex-rs/tui_app_server/src/lib.rs` never entered the blocking CI path.
This change cleans up the existing backlog, makes the default repo lint
path cover all Cargo targets, and starts rolling that stricter CI
enforcement out on the platform where it is currently validated.
## What changed
- mechanically fixed existing `argument-comment-lint` violations across
the `codex-rs` workspace, including tests, examples, and benches
- updated `tools/argument-comment-lint/run-prebuilt-linter.sh` and
`tools/argument-comment-lint/run.sh` so non-`--fix` runs default to
`--all-targets` unless the caller explicitly narrows the target set
- fixed both wrappers so forwarded cargo arguments after `--` are
preserved with a single separator
- documented the new default behavior in
`tools/argument-comment-lint/README.md`
- updated `rust-ci` so the macOS lint lane keeps the plain wrapper
invocation and therefore enforces `--all-targets`, while Linux and
Windows temporarily pass `-- --lib --bins`
That temporary CI split keeps the stricter all-targets check where it is
already cleaned up, while leaving room to finish the remaining Linux-
and Windows-specific target-gated cleanup before enabling
`--all-targets` on those runners. The Linux and Windows failures on the
intermediate revision were caused by the wrapper forwarding bug, not by
additional lint findings in those lanes.
## Validation
- `bash -n tools/argument-comment-lint/run.sh`
- `bash -n tools/argument-comment-lint/run-prebuilt-linter.sh`
- shell-level wrapper forwarding check for `-- --lib --bins`
- shell-level wrapper forwarding check for `-- --tests`
- `just argument-comment-lint`
- `cargo test` in `tools/argument-comment-lint`
- `cargo test -p codex-terminal-detection`
## Follow-up
- Clean up remaining Linux-only target-gated callsites, then switch the
Linux lint lane back to the plain wrapper invocation.
- Clean up remaining Windows-only target-gated callsites, then switch
the Windows lint lane back to the plain wrapper invocation.
Fixes#15283.
## Summary
Older system bubblewrap builds reject `--argv0`, which makes our Linux
sandbox fail before the helper can re-exec. This PR keeps using system
`/usr/bin/bwrap` whenever it exists and only falls back to vendored
bwrap when the system binary is missing. That matters on stricter
AppArmor hosts, where the distro bwrap package also provides the policy
setup needed for user namespaces.
For old system bwrap, we avoid `--argv0` instead of switching binaries:
- pass the sandbox helper a full-path `argv0`,
- keep the existing `current_exe() + --argv0` path when the selected
launcher supports it,
- otherwise omit `--argv0` and re-exec through the helper's own
`argv[0]` path, whose basename still dispatches as
`codex-linux-sandbox`.
Also updates the launcher/warning tests and docs so they match the new
behavior: present-but-old system bwrap uses the compatibility path, and
only absent system bwrap falls back to vendored.
### Validation
1. Install Ubuntu 20.04 in a VM
2. Compile codex and run without bubblewrap installed - see a warning
about falling back to the vendored bwrap
3. Install bwrap and verify version is 0.4.0 without `argv0` support
4. run codex and use apply_patch tool without errors
<img width="802" height="631" alt="Screenshot 2026-03-25 at 11 48 36 PM"
src="https://github.com/user-attachments/assets/77248a29-aa38-4d7c-9833-496ec6a458b8"
/>
<img width="807" height="634" alt="Screenshot 2026-03-25 at 11 47 32 PM"
src="https://github.com/user-attachments/assets/5af8b850-a466-489b-95a6-455b76b5050f"
/>
<img width="812" height="635" alt="Screenshot 2026-03-25 at 11 45 45 PM"
src="https://github.com/user-attachments/assets/438074f0-8435-4274-a667-332efdd5cb57"
/>
<img width="801" height="623" alt="Screenshot 2026-03-25 at 11 43 56 PM"
src="https://github.com/user-attachments/assets/0dc8d3f5-e8cf-4218-b4b4-a4f7d9bf02e3"
/>
---------
Co-authored-by: Michael Bolin <mbolin@openai.com>
## Problem
On Linux, Codex can be launched from a workspace path that is a symlink
(for example, a symlinked checkout or a symlinked parent directory).
Our sandbox policy intentionally canonicalizes writable/readable roots
to the real filesystem path before building the bubblewrap mounts. That
part is correct and needed for safety.
The remaining bug was that bubblewrap could still inherit the helper
process's logical cwd, which might be the symlinked alias instead of the
mounted canonical path. In that case, the sandbox starts in a cwd that
does not exist inside the sandbox namespace even though the real
workspace is mounted. This can cause sandboxed commands to fail in
symlinked workspaces.
## Fix
This PR keeps the sandbox policy behavior the same, but separates two
concepts that were previously conflated:
- the canonical cwd used to define sandbox mounts and permissions
- the caller's logical cwd used when launching the command
On the Linux bubblewrap path, we now thread the logical command cwd
through the helper explicitly and only add `--chdir <canonical path>`
when the logical cwd differs from the mounted canonical path.
That means:
- permissions are still computed from canonical paths
- bubblewrap starts the command from a cwd that definitely exists inside
the sandbox
- we do not widen filesystem access or undo the earlier symlink
hardening
## Why This Is Safe
This is a narrow Linux-only launch fix, not a policy change.
- Writable/readable root canonicalization stays intact.
- Protected metadata carveouts still operate on canonical roots.
- We only override bubblewrap's inherited cwd when the logical path
would otherwise point at a symlink alias that is not mounted in the
sandbox.
## Tests
- kept the existing protocol/core regression coverage for symlink
canonicalization
- added regression coverage for symlinked cwd handling in the Linux
bubblewrap builder/helper path
Local validation:
- `just fmt`
- `cargo test -p codex-protocol`
- `cargo test -p codex-core
normalize_additional_permissions_canonicalizes_symlinked_write_paths`
- `cargo clippy -p codex-linux-sandbox -p codex-protocol -p codex-core
--tests -- -D warnings`
- `cargo build --bin codex`
## Context
This is related to #14694. The earlier writable-root symlink fix
addressed the mount/permission side; this PR fixes the remaining
symlinked-cwd launch mismatch in the Linux sandbox path.
## Stack
fix: fail closed for unsupported split windows sandboxing #14172
-> fix: preserve split filesystem semantics in linux sandbox #14173
fix: align core approvals with split sandbox policies #14171
refactor: centralize filesystem permissions precedence #14174
## Summary
## Summary
- Preserve Linux split filesystem carveouts in bubblewrap by applying
mount masks in the right order, so narrower rules still win under
broader writable roots.
- Preserve unreadable ancestors of writable roots by masking them first
and then rebinding the narrower writable descendants.
- Stop rejecting legacy-plus-split Linux configs that are
sandbox-equivalent after `cwd` resolution by comparing semantics instead
of raw legacy structs.
- Fail closed when callers provide partial split policies, mismatched
legacy-plus-split policies, or force `--use-legacy-landlock` for
split-only shapes that legacy Landlock cannot enforce.
- Add Linux regressions for overlapping writable, read-only, and denied
paths, and document the supported split-policy enforcement path.
## Example
Given a split filesystem policy like:
```toml
[permissions.dev.filesystem]
":root" = "read"
"/code" = "write"
"/code/.git" = "read"
"/code/secrets" = "none"
"/code/secrets/tmp" = "write"
```
this PR makes Linux enforce the intended result under bubblewrap:
- `/code` stays writable
- `/code/.git` stays read-only
- `/code/secrets` stays denied
- `/code/secrets/tmp` can still be reopened as writable if explicitly
allowed
Before this, Linux could lose one of those carveouts depending on mount
order or legacy-policy fallback. This PR keeps the split-policy
semantics intact and rejects configurations that legacy Landlock cannot
represent safely.
## Summary
- make bubblewrap the default Linux sandbox and keep
`use_legacy_landlock` as the only override
- remove `use_linux_sandbox_bwrap` from feature, config, schema, and
docs surfaces
- update Linux sandbox selection, CLI/config plumbing, and related
tests/docs to match the new default
- fold in the follow-up CI fixes for request-permissions responses and
Linux read-only sandbox error text
## Why
After `#13449`, the Linux helper could receive split filesystem and
network policies, but the bubblewrap mount builder still reconstructed
filesystem access from the legacy `SandboxPolicy`.
That loses explicit unreadable carveouts under writable roots, and it
also mishandles `Root` read access paired with explicit deny carveouts.
In those cases bubblewrap could still expose paths that the split
filesystem policy intentionally blocked.
## What changed
- switched bubblewrap mount generation to consume
`FileSystemSandboxPolicy` directly at the implementation boundary;
legacy `SandboxPolicy` configs still flow through the existing
`FileSystemSandboxPolicy::from(&sandbox_policy)` bridge before reaching
bwrap
- kept the Linux helper and preflight path on the split filesystem
policy all the way into bwrap
- re-applied explicit unreadable carveouts after readable and writable
mounts so blocked subpaths still win under bubblewrap
- masked denied directories with `--tmpfs` plus `--remount-ro` and
denied files with `--ro-bind-data`, preserving the backing fd until exec
- added comments in the unreadable-root masking block to explain why the
mount order and directory/file split are intentional
- updated Linux helper call sites and tests for the split-policy bwrap
path
## Verification
- added protocol coverage for root carveouts staying scoped
- added core coverage that root-write plus deny carveouts still requires
a platform sandbox
- added bwrap unit coverage for reapplying blocked carveouts after
writable binds
- added Linux integration coverage for explicit split-policy carveouts
under bubblewrap
- validated the final branch state with `cargo test -p
codex-linux-sandbox`, `cargo clippy -p codex-linux-sandbox --all-targets
-- -D warnings`, and the PR CI reruns
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/13453).
* __->__ #13453
* #13452
* #13451
* #13449
* #13448
* #13445
* #13440
* #13439
---------
Co-authored-by: viyatb-oai <viyatb@openai.com>
## Why
The Linux sandbox helper still only accepted the legacy `SandboxPolicy`
payload.
That meant the runtime could compute split filesystem and network
policies, but the helper would immediately collapse them back to the
compatibility projection before applying seccomp or staging the
bubblewrap inner command.
## What changed
- added hidden `--file-system-sandbox-policy` and
`--network-sandbox-policy` flags alongside the legacy `--sandbox-policy`
flag so the helper can migrate incrementally
- updated the core-side Landlock wrapper to pass the split policies
explicitly when launching `codex-linux-sandbox`
- added helper-side resolution logic that accepts either the legacy
policy alone or a complete split-policy pair and normalizes that into
one effective configuration
- switched Linux helper network decisions to use `NetworkSandboxPolicy`
directly
- added `FromStr` support for the split policy types so the helper can
parse them from CLI JSON
## Verification
- added helper coverage in `linux-sandbox/src/linux_run_main_tests.rs`
for split-policy flags and policy resolution
- added CLI argument coverage in `core/src/landlock.rs`
- verified the current PR state with `just clippy`
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/13449).
* #13453
* #13452
* #13451
* __->__ #13449
* #13448
* #13445
* #13440
* #13439
---------
Co-authored-by: viyatb-oai <viyatb@openai.com>
## Summary
- always pass `--unshare-user` in the Linux bubblewrap argv builders
- stop relying on bubblewrap's auto-userns behavior, which is skipped
for `uid 0`
- update argv expectations in tests and document the explicit user
namespace behavior
The installed Codex binary reproduced the same issue with:
- `codex -c features.use_linux_sandbox_bwrap=true sandbox linux -- true`
- `bwrap: Creating new namespace failed: Operation not permitted`
This happens because Codex asked bubblewrap for mount/pid/network
namespaces without explicitly asking for a user namespace. In a
root-inside-container environment without ambient `CAP_SYS_ADMIN`, that
fails. Adding `--unshare-user` makes bubblewrap create the user
namespace first and then the remaining namespaces succeed.
Michael Bolin ·
viyatb-oai ·