rreichel3-oai
86764af684
## Problem Codex already treated an existing top-level project `./.codex` directory as protected, but there was a gap on first creation. If `./.codex` did not exist yet, a turn could create files under it, such as `./.codex/config.toml`, without going through the same approval path as later modifications. That meant the initial write could bypass the intended protection for project-local Codex state. ## What this changes This PR closes that first-creation gap in the Unix enforcement layers: - `codex-protocol` - treat the top-level project `./.codex` path as a protected carveout even when it does not exist yet - avoid injecting the default carveout when the user already has an explicit rule for that exact path - macOS Seatbelt - deny writes to both the exact protected path and anything beneath it, so creating `./.codex` itself is blocked in addition to writes inside it - Linux bubblewrap - preserve the same protected-path behavior for first-time creation under `./.codex` - tests - add protocol regressions for missing `./.codex` and explicit-rule collisions - add Unix sandbox coverage for blocking first-time `./.codex` creation - tighten Seatbelt policy assertions around excluded subpaths ## Scope This change is intentionally scoped to protecting the top-level project `.codex` subtree from agent writes. It does not make `.codex` unreadable, and it does not change the product behavior around loading project skills from `.codex` when project config is untrusted. ## Why this shape The fix is pointed rather than broad: - it preserves the current model of “project `.codex` is protected from writes” - it closes the security-relevant first-write hole - it avoids folding a larger permissions-model redesign into this PR ## Validation - `cargo test -p codex-protocol` - `cargo test -p codex-sandboxing seatbelt` - `cargo test -p codex-exec --test all sandbox_blocks_first_time_dot_codex_creation -- --nocapture` --------- Co-authored-by: Michael Bolin <mbolin@openai.com>
codex-core
This crate implements the business logic for Codex. It is designed to be used by the various Codex UIs written in Rust.
Dependencies
Note that codex-core makes some assumptions about certain helper utilities being available in the environment. Currently, this support matrix is:
macOS
Expects /usr/bin/sandbox-exec to be present.
When using the workspace-write sandbox policy, the Seatbelt profile allows
writes under the configured writable roots while keeping .git (directory or
pointer file), the resolved gitdir: target, and .codex read-only.
Network access and filesystem read/write roots are controlled by
SandboxPolicy. Seatbelt consumes the resolved policy and enforces it.
Seatbelt also supports macOS permission-profile extensions layered on top of
SandboxPolicy:
- no extension profile provided:
keeps legacy default preferences read access (
user-preference-read). - extension profile provided with no
macos_preferencesgrant: does not add preferences access clauses. macos_preferences = "readonly": enables cfprefs read clauses anduser-preference-read.macos_preferences = "readwrite": includes readonly clauses plususer-preference-writeand cfprefs shm write clauses.macos_automation = true: enables broad Apple Events send permissions.macos_automation = ["com.apple.Notes", ...]: enables Apple Events send only to listed bundle IDs.macos_launch_services = true: enables LaunchServices lookups and open/launch operations.macos_accessibility = true: enablescom.apple.axservermach lookup.macos_calendar = true: enablescom.apple.CalendarAgentmach lookup.macos_contacts = "read_only": enables Address Book read access and Contacts read services.macos_contacts = "read_write": includes the readonly Contacts clauses plus Address Book writes and keychain/temp helpers required for writes.
Linux
Expects the binary containing codex-core to run the equivalent of codex sandbox linux (legacy alias: codex debug landlock) when arg0 is codex-linux-sandbox. See the codex-arg0 crate for details.
Legacy SandboxPolicy / sandbox_mode configs are still supported on Linux.
They can continue to use the legacy Landlock path when the split filesystem
policy is sandbox-equivalent to the legacy model after cwd resolution.
Split filesystem policies that need direct FileSystemSandboxPolicy
enforcement, such as read-only or denied carveouts under a broader writable
root, automatically route through bubblewrap. The legacy Landlock path is used
only when the split filesystem policy round-trips through the legacy
SandboxPolicy model without changing semantics. That includes overlapping
cases like /repo = write, /repo/a = none, /repo/a/b = write, where the
more specific writable child must reopen under a denied parent.
The Linux sandbox helper prefers the first bwrap found on PATH outside the
current working directory whenever it is available. If bwrap is present but
too old to support --argv0, the helper keeps using system bubblewrap and
switches to a no---argv0 compatibility path for the inner re-exec. If
bwrap is missing, it falls back to the vendored bubblewrap path compiled into
the binary and Codex surfaces a startup warning through its normal notification
path instead of printing directly from the sandbox helper.
Windows
Legacy SandboxPolicy / sandbox_mode configs are still supported on
Windows.
The elevated setup/runner backend supports legacy ReadOnlyAccess::Restricted
for read-only and workspace-write policies. Restricted read access honors
explicit readable roots plus the command cwd, and keeps writable roots
readable when workspace-write is used.
When include_platform_defaults = true, the elevated Windows backend adds
backend-managed system read roots required for basic execution, such as
C:\Windows, C:\Program Files, C:\Program Files (x86), and
C:\ProgramData. When it is false, those extra system roots are omitted.
The unelevated restricted-token backend still supports the legacy full-read
Windows model for legacy ReadOnly and WorkspaceWrite behavior. It also
supports a narrow split-filesystem subset: full-read split policies whose
writable roots still match the legacy WorkspaceWrite root set, but add extra
read-only carveouts under those writable roots.
New [permissions] / split filesystem policies remain supported on Windows
only when they round-trip through the legacy SandboxPolicy model without
changing semantics. Policies that would require direct read restriction,
explicit unreadable carveouts, reopened writable descendants under read-only
carveouts, different writable root sets, or split carveout support in the
elevated setup/runner backend still fail closed instead of running with weaker
enforcement.
All Platforms
Expects the binary containing codex-core to simulate the virtual apply_patch CLI when arg1 is --codex-run-as-apply-patch. See the codex-arg0 crate for details.