Files
codex/codex-rs/core
iceweasel-oai 8ae0c837f0 Avoid PowerShell profiles in elevated Windows sandbox (#21400)
## Why

On Windows, elevated sandboxed commands run under a dedicated sandbox
account while `HOME` / `USERPROFILE` can still point at the real user's
profile directory. For PowerShell login shells, that combination can
make the sandbox account try to load the real user's PowerShell profile
script. If the sandbox account's execution policy differs from the real
user's policy, startup can emit profile-loading errors before the
requested command runs.

For this backend, loading the profile is not a faithful user login
shell: it is cross-account profile execution. Treating these PowerShell
invocations as non-login shells avoids that invalid startup path.

## Why This Happens Late

The normal `login` decision is resolved when shell argv is created, but
that point is too early to make this Windows sandbox-specific decision.
At argv creation time we do not yet know the actual sandbox attempt that
will run the command. A turn can include sandboxed and unsandboxed
attempts, and a broad turn-level override would also affect Full Access
commands where the user's profile should remain available.

Instead, this change carries the selected `ShellType` alongside the argv
and applies the `-NoProfile` adjustment in the shell runtimes once the
`SandboxAttempt` is known. That keeps the override scoped to actual
`WindowsRestrictedToken` attempts with `WindowsSandboxLevel::Elevated`.

The runtime uses the selected shell metadata rather than re-detecting
PowerShell from argv. That avoids brittle parsing and covers PowerShell
invocation shapes such as `-EncodedCommand`.

## What Changed

- Carry selected shell metadata through `exec_command` / unified exec
requests and shell tool requests.
- Insert `-NoProfile` for PowerShell commands only when the runtime is
about to execute a sandboxed elevated Windows attempt.
- Add focused unit coverage for elevated Windows PowerShell,
`-EncodedCommand`, existing `-NoProfile`, legacy restricted-token
attempts, unsandboxed attempts, and non-PowerShell commands.

## Verification

- `cargo test -p codex-core disable_powershell_profile_tests`
- `cargo test -p codex-core test_get_command`
- `cargo clippy --fix --tests --allow-dirty --allow-no-vcs -p
codex-core`

A full `cargo test -p codex-core` run was also attempted during
development, but it still hit an unrelated stack overflow in
`agent::control` tests before reaching this area.
2026-05-13 21:37:50 +00:00
..

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 keeps the legacy default preferences read access (user-preference-read) needed for cfprefs-backed macOS behavior.

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 bundled codex-resources/bwrap binary shipped with Codex and Codex surfaces a startup warning through its normal notification path instead of printing directly from the sandbox helper. Codex also surfaces a startup warning when bubblewrap cannot create user namespaces. WSL2 uses the normal Linux bubblewrap path. WSL1 is not supported for bubblewrap sandboxing because it cannot create the required user namespaces, so Codex rejects sandboxed shell commands that would enter the bubblewrap path before invoking bwrap.

Windows

Legacy SandboxPolicy / sandbox_mode configs are still supported on Windows. Legacy read-only and workspace-write policies imply full filesystem read access; exact readable roots are represented by split filesystem policies instead.

The elevated Windows sandbox also supports:

  • legacy ReadOnly and WorkspaceWrite behavior
  • split filesystem policies that need exact readable roots, exact writable roots, or extra read-only carveouts under writable roots
  • backend-managed system read roots required for basic execution, such as C:\Windows, C:\Program Files, C:\Program Files (x86), and C:\ProgramData, when a split filesystem policy requests platform defaults

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 can be enforced directly by the selected Windows backend or round-trip through the legacy SandboxPolicy model without changing semantics. Policies that would require direct explicit unreadable carveouts (none) or reopened writable descendants under read-only carveouts 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.