mirror of https://github.com/pchuan98/codex.git synced 2026-07-01 00:31:56 +08:00

Files

T

Eric Traut 4e0cf945b7 Terminate stdio MCP servers on shutdown to avoid process leaks (#19753 )

## Why

Several bug reports describe thread shutdown (including subagent
threads) leaving stdio MCP server processes behind. These reports all
point at the same lifecycle gap: Codex launches stdio MCP servers, but
the session-level shutdown path does not explicitly close MCP clients or
terminate the server process tree.

Fixes #12491
Fixes #12976
Fixes #18881
Fixes #19469

## History

This is best understood as a regression/coverage gap in MCP session
lifecycle management, not as stdio MCP cleanup being absent all along.
#10710 added process-group cleanup for stdio MCP servers, but that
cleanup only runs when the `RmcpClient`/transport is dropped. The older
reports (#12491 and #12976) came after that cleanup existed, which
suggests the remaining problem was that some higher-level shutdown paths
kept the MCP manager alive or replaced it without explicitly draining
clients. The newer reports (#18881 and #19469) exposed the same family
around manager replacement and shutdown.

## What changed

- Added an explicit stdio MCP process handle in `codex-rmcp-client` so
local MCP servers terminate their process group and executor-backed MCP
servers call the executor process terminator.
- Added `RmcpClient::shutdown()` and manager-level MCP shutdown draining
so session shutdown, channel-close fallback, MCP refresh, and connector
probing stop owned MCP clients.
- Added regression coverage that starts a stdio MCP server, begins an
in-flight blocking tool call, shuts down the client, and asserts the
server process exits.

## Verification

- `cargo test -p codex-rmcp-client`
- `cargo test -p codex-mcp`
- `just fix -p codex-rmcp-client`
- `just fix -p codex-mcp`
- `just fix -p codex-core`

- Manual before/after validation with a temporary repro script:
- Pre-fix binary from `HEAD^` (`fed0a8f4fa`): reproduced the leak with
surviving MCP server and child PIDs, `survivors=[77583, 77592]`,
`leaked=true`.
- Post-fix binary from this branch (`67e318148b`): verified both MCP
processes were gone after interrupting `codex exec`, `survivors=[]`,
`leaked=false`.

4e0cf945b7 · 2026-04-28 09:29:57 -07:00

History

src

Terminate stdio MCP servers on shutdown to avoid process leaks (#19753 )

2026-04-28 09:29:57 -07:00

templates

chore: split memories part 1 (#19818 )

2026-04-27 16:01:05 +02:00

tests

feat: split memories part 2 (#19860 )

2026-04-28 13:03:28 +02:00

BUILD.bazel

test: increase core-all-test shard count to 16 (#19727 )

2026-04-26 23:10:26 +00:00

Cargo.toml

feat: split memories part 2 (#19860 )

2026-04-28 13:03:28 +02:00

config.schema.json

feat(tui): add configurable keymap support (#18593 )

2026-04-28 12:52:25 -03:00

gpt_5_1_prompt.md

Assemble sandbox/approval/network prompts dynamically (#8961 )

2026-01-12 23:12:59 +00:00

gpt_5_2_prompt.md

Assemble sandbox/approval/network prompts dynamically (#8961 )

2026-01-12 23:12:59 +00:00

gpt_5_codex_prompt.md

Assemble sandbox/approval/network prompts dynamically (#8961 )

2026-01-12 23:12:59 +00:00

gpt-5.1-codex-max_prompt.md

Assemble sandbox/approval/network prompts dynamically (#8961 )

2026-01-12 23:12:59 +00:00

gpt-5.2-codex_prompt.md

Assemble sandbox/approval/network prompts dynamically (#8961 )

2026-01-12 23:12:59 +00:00

hierarchical_agents_message.md

Add hierarchical agent prompt (#8996 )

2026-01-09 13:47:37 -08:00

prompt_with_apply_patch_instructions.md

Assemble sandbox/approval/network prompts dynamically (#8961 )

2026-01-12 23:12:59 +00:00

README.md

permissions: remove legacy read-only access modes (#19449 )

2026-04-24 17:16:58 -07:00

review_prompt.md

docs: Fix markdown list item spacing in codex-rs/core/review_prompt.md (#4144 )

2025-10-30 17:39:21 -07:00

README.md

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 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. 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.