fix(sandbox): spawn confined argv directly (round 1)

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Hypatia May
2026-08-04 12:04:48 +08:00
parent 2eedb54849
commit e36d040d0a
34 changed files with 392 additions and 282 deletions

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@@ -2,5 +2,5 @@
# side as of the last confirmed-consistent state. Both languages carry equal authority;
# after editing either side, bring the other along and re-record with:
# pnpm run verify-translation-pairing --write .agents/notes/implemented/feature/2026-07-06-sandbox.md
2026-07-06-sandbox.md: 85c7f64d379e4fec18511b3b8566e84edb34c1a2
2026-07-06-sandbox.zh.md: 0278b6302d2647c49980b10646e3b9158356b3ec
2026-07-06-sandbox.md: c3f78c4bd05063c7c34621e6a3ec007d394b6d4c
2026-07-06-sandbox.zh.md: 984a8d71854344d41280e956b3c985659a9b066c

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@@ -36,9 +36,9 @@ Four `cordis.yml` entries turn an unconfined coding agent into the sandboxed pro
name: '@deepseek-ai/dsh-permission' # one product-facing select over both mechanism knobs
```
The swap is invisible to every consumer of `ctx.bash`: the bash tools, hook commands, and background tasks run exactly as before, spawned through the wrapped argv the provider returns. Deleting the `sandbox` and `permission` entries and replacing `bash` with `@deepseek-ai/dsh-bash-local` is the opt-out — execution is unconfined again and the escalation fields vanish from the tool schema, because they are capability-gated on the mounted executor, not on configuration. Omitting only `approval` keeps confinement but fails every escalation closed with its own error text; `permission` also requires the approval seam and a confining executor, so a partially composed preset layer fails loud at load.
The swap is invisible to every consumer of `ctx.bash`: the bash tools, hook commands, and background tasks run exactly as before by directly spawning the wrapped argv the provider returns. Deleting the `sandbox` and `permission` entries and replacing `bash` with `@deepseek-ai/dsh-bash-local` is the opt-out — execution is unconfined again and the escalation fields vanish from the tool schema, because they are capability-gated on the mounted executor, not on configuration. Omitting only `approval` keeps confinement but fails every escalation closed with its own error text; `permission` also requires the approval seam and a confining executor, so a partially composed preset layer fails loud at load.
Misconfiguration fails loud: `mode` outside the closed vocabulary is rejected at plugin load, and a host with no usable backend throws the structured `SANDBOX_UNAVAILABLE` — at `confine()` before the command ever spawns — rather than degrading to unconfined execution. `runnerCommand` on `dsh-sandbox-local` is the operator's explicit assertion of a bwrap-compatible runner (chain and probes skipped); it doubles as the deterministic fake-runner seam for keyless tests.
Misconfiguration fails loud: `mode` outside the closed vocabulary is rejected at plugin load, and a host with no usable backend throws the structured `SANDBOX_UNAVAILABLE` at `confine()` rather than degrading to unconfined execution. If the selected runner cannot spawn, the consumer reports the same infrastructure error from the spawn channel before any command starts. `runnerCommand` on `dsh-sandbox-local` is the operator's explicit assertion of a bwrap-compatible runner (chain and probes skipped); it doubles as the deterministic fake-runner seam for keyless tests.
Denied file effects return a `[sandbox: file access denied under <mode> mode]` marker and instructions not to work around the denial. A confining executor adds paired `sandbox_permissions` and `justification` fields for one approved retry that must be strictly wider than the session's effective mode. A grant widens only that retry; rejection executes nothing, returns `the user rejected escalating this command to "<mode>"`, and permits no re-ask. The owner-derived runtime context states the current file policy without replacing those enforcement boundaries. When `dsh-permission` is composed with a UI adapter, one preset selects both knob values; unmatched values fold to `custom`. The [ACP automation composition](../../../../examples/acp-agent/README.md) does not mount that UI service and selects its deployment mode explicitly.
@@ -60,17 +60,17 @@ Left open, for the phase that needs them: whether network restriction arrives as
#### Local backends and the shipped launcher
`dsh-sandbox-local` selects one platform runner per provider lifetime and caches the verdict. Linux functionally probes `bwrap` then Landlock; macOS uses Seatbelt. Unsupported platforms and unusable runners fail closed. Each wrap carries backend-specific denial signatures and runner-failure rules so `dsh-bash-sandbox` can distinguish a denied file effect from a broken sandbox. Landlock runner failure requires exit 125 plus a non-notice `landlock-run:` line; the exact partial-enforcement line is informational even when a child exits 1, 2, or 125. Outer-shell failures are separate rules scoped to the resolved/configured argv0 and shell exit 126/127. `runnerCommand` keeps its operator-facing `runnerFailureSignatures` config and maps those entries into an internal fatal rule, but missing or unexecutable commands still classify as sandbox failure and never run the payload unconfined.
`dsh-sandbox-local` selects one platform runner per provider lifetime and caches the verdict. Linux functionally probes `bwrap` then Landlock; macOS uses Seatbelt. Unsupported platforms and unusable runners fail closed. Each wrap carries backend-specific denial signatures and runner-failure rules so `dsh-bash-sandbox` can distinguish a denied file effect from a broken sandbox. Landlock runner failure requires exit 125 plus a non-notice `landlock-run:` line; the exact partial-enforcement line is informational even when a child exits 1, 2, or 125. Bubblewrap and Seatbelt remain signature-only because neither public contract reserves a launcher-failure status. `runnerCommand` keeps its operator-facing `runnerFailureSignatures` config, requires non-empty single-line entries, and maps them into one internal fatal rule. The consumer directly spawns every returned argv, so missing or unexecutable runners fail through the spawn channel while a successfully launched child exit 126 or 127 remains ordinary. An operator-configured Bash script necessarily owns its interpreter startup before it applies its profile.
The launcher is a ~300-line C program (plain C11 over the raw Landlock UAPI — no libraries beyond a statically linked musl, so the audit surface is that one file plus the kernel's stable syscall contract): `--ro <path>` / `--rw <path>` grants, `--`, the wrapped argv; it installs the ruleset on itself and `exec`s (rulesets are inherited across `execve`, and it sets `no_new_privs` before restricting); `--probe` enforces a maximal ruleset in a short-lived child and exits 0 only when the kernel actually enforces; launcher failures exit 125 without exec'ing and print a fatal `landlock-run:` line. An older ABI prints the exact `landlock-run: partial enforcement (older Landlock ABI)` notice before it executes the child, so that line is not fatal evidence.
The launcher is a ~300-line C program (plain C11 over the raw Landlock UAPI — no libraries beyond a statically linked musl, so the audit surface is that one file plus the kernel's stable syscall contract): `--ro <path>` / `--rw <path>` grants, `--`, the wrapped argv; it installs the ruleset on itself and `exec`s (rulesets are inherited across `execve`, and it sets `no_new_privs` before restricting); `--probe` enforces a maximal ruleset in a short-lived child and exits 0 only when the kernel actually enforces; every launcher failure exits 125 without running the child and prints a fatal `landlock-run:` line. A successfully exec'd child may also return 125, so status alone is not launcher evidence. An older ABI prints the exact `landlock-run: partial enforcement (older Landlock ABI)` notice before it executes the child, so that line is not fatal evidence.
The Landlock launcher source and package workspace live at `native/landlock-run`, next to the harness consumers. The standalone [`node-addon-landlock-run`](https://github.com/deepseek-harness/node-addon-landlock-run) repository is the release mirror used to pack and publish the npm package family; `native/README.md` owns the export procedure. Platform binaries are selected by npm, and the entry package owns path resolution, probing, and CLI flags while the harness maps sandbox modes to grants. Versioning the entry point with its binaries keeps probe parsing and launch syntax aligned.
The Landlock launcher source and package workspace live at `native/landlock-run`, next to the harness consumers. The standalone [`node-addon-landlock-run`](https://github.com/deepseek-harness/node-addon-landlock-run) repository is the release mirror used to pack and publish the npm package family; `native/README.md` owns the export procedure. Platform binaries are selected by npm, and the entry package owns path resolution, probing, CLI flags, the fatal prefix, and the partial-enforcement notice while the harness maps sandbox modes to grants. Versioning the entry point with its binaries keeps probe parsing and launch syntax aligned.
Backend profiles share the mode contract but differ in necessary host grants. Landlock and Seatbelt allow only `/dev/null` in read-only mode; workspace-write also permits their required host temp roots. Each wrap carries backend-specific denial signatures. Landlock reports partial enforcement on older ABIs that cannot govern every operation, while successful bwrap and Seatbelt profiles report full enforcement.
#### The bash consumer
`dsh-bash-sandbox` extends `LocalBashExecutor` and hands `ctx.sandbox` the exact `['bash', '-c', command]` argv it is about to spawn. A denial is an orthogonal result fact, conservatively classified from the active runner's stderr dialect. Foreground and background use one runner-failure classifier that requires the rule's exit-code gate and a remaining fatal line after informational exclusions. A match outranks denial: foreground execution throws `SANDBOX_UNAVAILABLE` with that fatal line as detail; a settled `BashProcess` stamps `sandbox.runnerFailed`, and the bash producer renders it through generic `task_output`.
`dsh-bash-sandbox` extends `LocalBashExecutor`, hands `ctx.sandbox` the exact `['bash', '-c', command]` argv, and directly spawns the provider result. This leaves shell semantics and `BASH_ENV` on the inner Bash after the shipped native runner establishes confinement. A provider error propagates unchanged; a provider-argv spawn rejection becomes `SANDBOX_UNAVAILABLE` with its original detail in foreground and stamps `runnerFailed: true`, `denied: false` in background. After a process starts, foreground and background use one runner-failure classifier that requires the rule's exit-code gate and a remaining fatal line after informational exclusions. A match outranks denial: foreground execution throws `SANDBOX_UNAVAILABLE` with that fatal line as detail; a settled `BashProcess` stamps `sandbox.runnerFailed`, and the bash producer renders it through generic `task_output`.
The model sees the current effective file policy in the owner-derived `sandbox:policy` runtime context, while the static tool description explains the denial marker (`[sandbox: file access denied under <mode> mode]`), encourages attempting commands that may be denied, and forbids retrying around a denial; when the escalation fields are advertised, a denied result additionally carries the escalation hint itself, so the sanctioned same-turn retry is prompted at the decision point rather than depending on the model recalling the description (§ Escalation). [The current-policy decision](2026-07-30-current-sandbox-policy-context.md) owns the context's rationale and boundaries.
@@ -78,7 +78,7 @@ The model sees the current effective file policy in the owner-derived `sandbox:p
`BashExecRequest.sandboxPolicy` is an optional complete per-call input; resolved specs make the field explicit. `BashExecutor.sandboxMode` remains the capability fact advertising whether the mounted executor can honor that policy, so only a confining composition exposes escalation. The seam accepts any explicit policy; the tool owns session resolution and the wider-only escalation rule. Non-sandboxing executors remain honestly unconfined.
`ctx.sandboxPolicy.resolve()` stamps the complete execution policy — explicit escalation mode > session override > configured default, with `SessionHeader.cwd` > configured fallback root — before the executor runs. `SandboxBashExecutor.resolve()` retains that policy on the spec, or supplies the deployment fallback for a direct agentless caller, so `run()`/`start()` never read mutable session state. Per-process wrap facts are keyed by the returned `BashProcess`; `onProcessDone()` classifies stderr and stamps that handle before `done` resolves, so overlapping processes retain their own modes and runner dialects.
`ctx.sandboxPolicy.resolve()` stamps the complete execution policy — explicit escalation mode > session override > configured default, with `SessionHeader.cwd` > configured fallback root — before the executor runs. `SandboxBashExecutor.resolve()` retains that policy on the spec, or supplies the deployment fallback for a direct agentless caller, so `run()`/`start()` never read mutable session state. Per-process wrap facts are keyed by the returned `BashProcess`; `onProcessDone()` receives spawn failure out of band from stderr classification and stamps that handle before `done` resolves, so overlapping processes retain their own modes and runner dialects.
When a confining executor is mounted, `bash` advertises paired `sandbox_permissions` and `justification` fields. The schema exposes the full closed escalation vocabulary because effective mode is per-session; execution rejects any target that is not strictly wider than that call's effective mode. Approval resolves before execution. `allowed-once` stamps the granted mode onto only that request, while `rejected`, `cancelled`, `unavailable`, a missing approval service, or a missing agent all fail closed with distinct results. No grant is persisted.
@@ -117,7 +117,7 @@ fs/web/todo execute in-process, so their sandbox semantics are policy at their s
### Testing
- **Unit:** pin platform selection and profiles, structured runner classification (including partial-Landlock notice-only child outcomes, fatal evidence, outer-shell failures, and foreground/background parity), per-call mode/root resolution, per-process facts, escalation validation and outcomes, permission preset folding and write-through, and runtime-context ordering and materialization.
- **Unit:** pin platform selection and profiles, direct provider-argv handoff, spawn-level failures, confined `BASH_ENV` ordering, structured runner classification (including partial-Landlock notice-only child outcomes, gated fatal evidence, child exits 126/127, and foreground/background parity), per-call mode/root resolution, per-process facts, escalation validation and outcomes, permission preset folding and write-through, and runtime-context ordering and materialization.
- **Keyless real-runner:** exercise bwrap, Landlock, and Seatbelt against real filesystem effects at provider and bash-consumer layers; one real Cordis context concurrently drives two project sessions through shipped bash and fs tools, proving own-root success and sibling-root denial. Packed-install coverage proves the registry launcher remains executable. CI rejects a silent all-skip.
- **With-key:** start the real ACP composition in read-only mode, let a model-driven bash write hit the runner's denial marker, then drive the bridge answerer and disk effect through granted and rejected workspace-write retries; unavailable credentials or runners self-skip.
- **Snapshot:** pin the atomic current-policy context and both scripted approval branches. A real ACP example scenario places its session under the user home while the deployment fallback points at `/tmp`, then pins both the workspace-write runtime-context message and a successful deployment-selected mutation; this distinguishes session-root resolution from the process fallback without depending on runner-specific denial text. A POSIX fake partial-Landlock provider pins direct bash `false` as an ordinary child result through the assembled app. Other snapshots start unconfined so unrelated fixtures remain platform-independent.
@@ -172,20 +172,20 @@ Costs and accepted limits:
- **The one-wrapper illusion is given up knowingly.** A `tools/pre-execute` wrapper plus prompt conventions does not solve sandbox approval — the correct design costs structured denials, native runner probes, per-call policy carriage, and consistent cross-family enforcement, and this design pays it.
- **`read-only` became a cross-family boundary through a follow-up.** This RFC shipped bash-only enforcement; the [cross-family fs sandbox RFC](2026-07-14-cross-family-fs-sandbox.md) extends the same mode vocabulary to the filesystem tools through a sandboxed `ctx.fs` provider and relocates the mode/root config and the `sandbox/mode` override to `ctx.sandboxPolicy` (§ In-process tools).
- **Windows has no backend.** Its chain slot is reserved empty — fail-closed, never a fallthrough; filling it is a deferred phase.
- **The Seatbelt rung leans on Apple's deprecated-but-shipped `sandbox-exec` CLI.** As darwin's sole candidate it is selected without probing, so a future removal surfaces at execution as the runner-failure classification — re-thrown `SANDBOX_UNAVAILABLE`, the command never runs; fail closed, never open.
- **The Seatbelt rung leans on Apple's deprecated-but-shipped `sandbox-exec` CLI.** As darwin's sole candidate it is selected without probing, so a future removal surfaces as a direct spawn failure and an executable refusal through its fatal signature — both become `SANDBOX_UNAVAILABLE`, and the command never runs; fail closed, never open.
- **Landlock confinement is only as complete as the running kernel's ABI.** Reported as `enforcement: 'partial'` rather than refused — the deliberate trade that keeps the fallback available on older-kernel hosts.
- **Runner attribution uses an in-band protocol.** Exit status plus stderr cannot cryptographically identify the writer, so a confined child can mimic a fatal runner line and status to cause an availability/diagnostic false attribution. The conjunction and exact notice exclusion reduce accidental matches; this is not a sandbox bypass because the child is already confined.
- **The launcher arrives as a registry dependency.** Trusted through its own repository's release pipeline (reviewed C source, native CI builders, byte-pinned publish rehearsal) plus this repo's version pin — the real-kernel e2e legs are what vouch for behavior through the installed bytes.
- **The model may over-ask.** Escalating without denial grounding, or picking `danger-full-access` where `workspace-write` suffices: the description steers and the enum forces the ladder, but the human prompt is the actual gate; the `approval/asked` reasons make over-asking auditable, and a `prepend` policy answerer can auto-reject patterns a deployment never wants.
- **The advertised target set is static while the effective mode is per-session** (schemas are registry-global) — a session already at the widest mode is still offered the fields. Harmless by construction: the strict-wider check at execution, not the enum, is the safety boundary — a non-widening request fails with its own text and never prompts anyone.
- **A granted escalation is not a working sandbox.** An unavailable backend still fails closed even for a granted escalation to a confining mode — at `confine()` when the platform has no chain or every probe fails, at execution when an unprobed sole runner refuses (classified as a sandbox failure, not a command failure) — while a granted `danger-full-access` run never touches the provider at all: there the grant, not the probe, is the authority.
- **A granted escalation is not a working sandbox.** An unavailable backend still fails closed even for a granted escalation to a confining mode — at `confine()` when the platform has no chain or every probe fails, through the spawn channel when the selected executable cannot start, or through a structured rule when a started runner refuses — while a granted `danger-full-access` run never touches the provider at all: there the grant, not the probe, is the authority.
- **Runtime-context history is append-only.** A policy switch appends a complete superseding snapshot after retained history, preserving the stable system-and-conversation prefix; unchanged state adds no message.
- **Older policy snapshots remain in history.** Each full snapshot explicitly supersedes earlier runtime-context snapshots, so replay and compaction need only retain the latest materialized message.
## FAQ
- **A command came back with `[sandbox: file access denied under read-only mode]` — did it fail?** It RAN, and the kernel refused a file effect: the denial is a result fact orthogonal to exit code. The teaching forbids retrying around it; the one sanctioned move is the same command retried once with an escalation request.
- **How is a BROKEN sandbox told apart from a failing command?** Runner failure outranks denial only when one `runnerFailureRules` entry matches both its optional exit-code gate and a fatal stderr line after exact informational exclusions. Foreground re-throws structured `SANDBOX_UNAVAILABLE` with the matched fatal line; a background task stamps `sandbox.runnerFailed` and renders its own marker. A Landlock partial-enforcement notice plus an ordinary child failure remains a command result.
- **How is a BROKEN sandbox told apart from a failing command?** A provider-argv spawn rejection proves the confined launch never started. After it starts, runner failure outranks denial only when one `runnerFailureRules` entry matches both its optional exit-code gate and a fatal stderr line after exact informational exclusions. Foreground throws structured `SANDBOX_UNAVAILABLE` with spawn or matched-line detail; a background task stamps `sandbox.runnerFailed` and renders its own marker. A Landlock partial-enforcement notice plus an ordinary child failure remains a command result.
- **What happens on a platform with no backend — Windows today?** `confine()` throws the fail-closed `SANDBOX_UNAVAILABLE` and the command never spawns; `win32` is a reserved EMPTY chain, pinned by test to fail closed identically until a Windows runner fills it (§ Deferred phases).
- **`bwrap` is installed on my host but unusable (disabled unprivileged userns, an LSM denying `mount`) — what happens?** The chain probe is functional — it builds and enforces a real profile rather than checking `--version` — so a present-but-unusable `bwrap` fails its probe, selection falls to the registry-installed Landlock launcher, and the verdict is cached for the provider's lifetime.
- **Does the sandbox restrict network or process visibility?** No — `SandboxMode` claims FILE effects only; the bwrap profile deliberately does not unshare pid, and no backend claims network. Whether network restriction becomes its own knob is left open in § The seam.

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@@ -36,9 +36,9 @@ harness 是一个 SDK,因此约束必须是开发者可组合的能力:是
name: '@deepseek-ai/dsh-permission' # one product-facing select over both mechanism knobs
```
这一替换对 `ctx.bash` 的所有消费方透明:bash 工具、钩子命令和后台任务照常运行,通过提供方返回的包装 argv spawn。删除 `sandbox` 和 `permission` 条目、将 `bash` 替换为 `@deepseek-ai/dsh-bash-local` 即为退出——执行恢复为无约束,升级字段从工具 schema 中消失,因为它们是基于已挂载执行器的能力门控,而非基于配置。仅省略 `approval` 则保留约束但以自身错误文本关闭每次升级;`permission` 还要求 approval seam 和约束执行器同时存在,因此部分组合的 preset 层在加载时即大声失败。
这一替换对 `ctx.bash` 的所有消费方透明:bash 工具、钩子命令和后台任务照常运行,直接 spawn 提供方返回的已包装 argv。删除 `sandbox` 和 `permission` 条目、将 `bash` 替换为 `@deepseek-ai/dsh-bash-local` 即为退出——执行恢复为无约束,升级字段从工具 schema 中消失,因为它们是基于已挂载执行器的能力门控,而非基于配置。仅省略 `approval` 则保留约束但以自身错误文本关闭每次升级;`permission` 还要求 approval seam 和约束执行器同时存在,因此部分组合的 preset 层在加载时即大声失败。
配置错误大声失败:`mode` 不在封闭词汇中时在插件加载时被拒绝;主机上没有可用后端时在 `confine()` 阶段(命令 spawn 之前)抛出结构化的 `SANDBOX_UNAVAILABLE`,而非降级为无约束执行。`dsh-sandbox-local` 上的 `runnerCommand` 是运维人员对一个 bwrap 兼容 runner 的显式断言(跳过链和探测);它同时充当 keyless 测试的确定性 fake-runner seam。
配置错误大声失败:`mode` 不在封闭词汇中时在插件加载时被拒绝;主机上没有可用后端时在 `confine()` 阶段抛出结构化的 `SANDBOX_UNAVAILABLE`,而非降级为无约束执行。如果所选 runner 无法 spawn,消费方会在任何命令开始前通过 spawn 通道报告同一基础设施错误。`dsh-sandbox-local` 上的 `runnerCommand` 是运维人员对一个 bwrap 兼容 runner 的显式断言(跳过链和探测);它同时充当 keyless 测试的确定性 fake-runner seam。
被拒绝的文件操作返回 `[sandbox: file access denied under <mode> mode]` 标记,并附带不要绕过拒绝的指令。约束执行器添加配对的 `sandbox_permissions` 和 `justification` 字段,用于一次经批准的重试,该重试必须严格宽于会话的有效模式。授权仅放宽该次重试;拒绝则不执行任何内容,返回 `the user rejected escalating this command to "<mode>"`,且不允许再次请求。由归属方派生的运行时上下文会说明当前文件策略,但不会取代这些强制执行边界。当 `dsh-permission` 与某个 UI 适配器一起组合时,一个 preset 同时选定两个旋钮值;不匹配的组合折叠为 `custom`。[ACP 自动化组合](../../../../examples/acp-agent/README.md)不挂载该 UI 服务,而是显式选定其部署模式。
@@ -60,17 +60,17 @@ OS 子进程约束适用于 bash 执行器(包括钩子命令),后续还
#### 本地后端与随附 launcher
`dsh-sandbox-local` 在提供方生命周期内选择一个平台 runner 并缓存结论。Linux 功能性探测 `bwrap` 然后 Landlock;macOS 使用 Seatbelt。不支持的平台和不可用的 runner 失败关闭。每次包装携带后端特定的拒绝签名和 runner 失败规则,以便 `dsh-bash-sandbox` 区分被拒绝的文件操作与损坏的沙箱。Landlock runner 失败需要退出码 125,加上一行不是通知的 `landlock-run:` 诊断;即使子进程以 1、2 或 125 退出,精确匹配的部分强制执行通知仍只是信息。外层 shell 失败使用独立规则,并限定为解析后或配置的 argv0 与 shell 退出码 126/127。`runnerCommand` 保留面向运维人员的 `runnerFailureSignatures` 配置,并将这些条目映射到一条内部致命规则;但命令缺失或不可执行时,仍归类为沙箱失败,绝不无约束地运行负载。
`dsh-sandbox-local` 在提供方生命周期内选择一个平台 runner 并缓存结论。Linux 功能性探测 `bwrap` 然后 Landlock;macOS 使用 Seatbelt。不支持的平台和不可用的 runner 失败关闭。每次包装携带后端特定的拒绝签名和 runner 失败规则,以便 `dsh-bash-sandbox` 区分被拒绝的文件操作与损坏的沙箱。Landlock runner 失败需要退出码 125,加上一行不是通知的 `landlock-run:` 诊断;即使子进程以 1、2 或 125 退出,精确匹配的部分强制执行通知仍只是信息。Bubblewrap 和 Seatbelt 仍仅依据签名,因为两者的公开契约均未保留 launcher 失败状态。`runnerCommand` 保留面向运维人员的 `runnerFailureSignatures` 配置,要求其中条目均为非空单行,并将它们映射为一条内部致命规则。消费方会直接 spawn 每个返回的 argv,因此 runner 缺失或不可执行时会通过 spawn 通道失败,而成功启动的子进程以 126 或 127 退出时仍按普通结果处理。运维人员配置的 Bash 脚本必然要先启动解释器,再应用自身 profile。
launcher 是一个约 300 行的 C 程序(纯 C11,直接使用 Landlock UAPI——除静态链接的 musl 外无其他库,因此审计面仅为该文件加内核的稳定 syscall 契约):`--ro <path>` / `--rw <path>` 授权,`--`,被包装的 argv;它在自身上安装规则集并 `exec`(规则集跨 `execve` 继承,且它在限制前设置 `no_new_privs`);`--probe` 在一个短生命周期子进程中强制最大规则集,仅当内核确实强制时才以 0 退出;launcher 失败以 125 退出且不 exec,并打印一行致命的 `landlock-run:` 诊断。较旧的 ABI 会在执行子进程之前打印精确的 `landlock-run: partial enforcement (older Landlock ABI)` 通知,因此该行不是致命证据。
launcher 是一个约 300 行的 C 程序(纯 C11,直接使用 Landlock UAPI——除静态链接的 musl 外无其他库,因此审计面仅为该文件加内核的稳定 syscall 契约):`--ro <path>` / `--rw <path>` 授权,`--`,被包装的 argv;它在自身上安装规则集并 `exec`(规则集跨 `execve` 继承,且它在限制前设置 `no_new_privs`);`--probe` 在一个短生命周期子进程中强制最大规则集,仅当内核确实强制时才以 0 退出;所有 launcher 失败都会以 125 退出且不运行子进程,并打印一行致命的 `landlock-run:` 诊断。成功完成 exec 的子进程也可能返回 125,因此仅凭退出状态不能作为 launcher 失败的证据。较旧的 ABI 会在执行子进程之前打印精确的 `landlock-run: partial enforcement (older Landlock ABI)` 通知,因此该行不是致命证据。
Landlock launcher 源码和包工作区位于 `native/landlock-run`,与 harness 消费方同仓。独立的 [`node-addon-landlock-run`](https://github.com/deepseek-harness/node-addon-landlock-run) 仓库是用于打包并发布 npm 包族的发布镜像;导出流程归 `native/README.md` 所有。平台二进制由 npm 选择,入口包拥有路径解析、探测和 CLI flag,而 harness 将沙箱模式映射为授权。将入口点与其二进制一起版本化,使探测解析和启动语法保持对齐。
Landlock launcher 源码和包工作区位于 `native/landlock-run`,与 harness 消费方同仓。独立的 [`node-addon-landlock-run`](https://github.com/deepseek-harness/node-addon-landlock-run) 仓库是用于打包并发布 npm 包族的发布镜像;导出流程归 `native/README.md` 所有。平台二进制由 npm 选择,入口包拥有路径解析、探测、CLI flag、致命前缀和部分强制执行通知,而 harness 将沙箱模式映射为授权。将入口点与其二进制一起版本化,使探测解析和启动语法保持对齐。
后端 profile 共享模式契约但在必要的主机授权上有所不同。Landlock 和 Seatbelt 在 read-only 模式下仅允许 `/dev/null`;workspace-write 还允许各自所需的主机临时目录根。每次包装携带后端特定的拒绝签名。Landlock 在较旧的 ABI 无法管控所有操作时报告 partial enforcement,而成功的 bwrap 和 Seatbelt profile 报告 full enforcement。
#### bash 消费方
`dsh-bash-sandbox` 扩展 `LocalBashExecutor`,并把即将 spawn 的确切 `['bash', '-c', command]` argv 交给 `ctx.sandbox`。拒绝是与其他结果正交的事实,依据当前 runner 的 stderr 方言保守分类。前台与后台共用一个 runner 失败分类器:先排除信息性行,再要求规则的退出码门控与余下的一行致命诊断同时匹配。匹配结果优先于拒绝:前台执行抛出 `SANDBOX_UNAVAILABLE`,并以该致命行作为详细信息;结算后的 `BashProcess` 会盖章 `sandbox.runnerFailed`,bash 生产者再通过通用 `task_output` 渲染它。
`dsh-bash-sandbox` 扩展 `LocalBashExecutor`,把精确的 `['bash', '-c', command]` argv 交给 `ctx.sandbox`,并直接 spawn 提供方返回的 argv。这样,随附的原生 runner 建立约束后,shell 语义与 `BASH_ENV` 仍由内层 Bash 处理。提供方错误原样传播;spawn 提供方 argv 遭拒时,前台会将其转为 `SANDBOX_UNAVAILABLE` 并附上原始详细信息,后台则盖章 `runnerFailed: true`、`denied: false`。进程启动后,前台与后台共用一个 runner 失败分类器:先排除信息性行,再要求规则的退出码门控与余下的一行致命诊断同时匹配。匹配结果优先于拒绝:前台执行抛出 `SANDBOX_UNAVAILABLE`,并以该致命行作为详细信息;结算后的 `BashProcess` 会盖章 `sandbox.runnerFailed`,bash 生产者再通过通用 `task_output` 渲染它。
模型会在归属方派生的 `sandbox:policy` 运行时上下文中看到当前有效的文件策略;静态工具描述则解释拒绝标记(`[sandbox: file access denied under <mode> mode]`),鼓励尝试可能被拒绝的命令,并禁止绕过拒绝重试。当升级字段被公布时,被拒绝的结果还会携带升级提示本身,使被认可的同轮次重试在决策点获得提示,而非依赖模型回忆描述(§ 升级机制)。[当前策略决策](2026-07-30-current-sandbox-policy-context.md)负责该上下文的理由与边界。
@@ -78,7 +78,7 @@ Landlock launcher 源码和包工作区位于 `native/landlock-run`,与 harnes
`BashExecRequest.sandboxPolicy` 是可选的完整按调用输入;解析后的 spec 使该字段显式。`BashExecutor.sandboxMode` 仍是公布已挂载执行器能否兑现该策略的能力事实,因此只有约束组合才暴露升级。seam 接受任何显式策略;工具拥有会话解析和「仅更宽」的升级规则。非沙箱执行器诚实地保持无约束。
`ctx.sandboxPolicy.resolve()` 在执行器运行前盖章完整执行策略——显式升级模式 > 会话覆盖 > 配置默认值,且 `SessionHeader.cwd` > 配置的后备根目录。`SandboxBashExecutor.resolve()` 在 spec 上保留该策略,或为直接的无 agent 调用方提供部署后备值,使 `run()`/`start()` 永不读取可变会话状态。每进程包装事实以返回的 `BashProcess` 为键;`onProcessDone()` 在 `done` 结算前分类 stderr 并给该句柄盖章,因此重叠进程各自保留自己的模式和 runner 方言。
`ctx.sandboxPolicy.resolve()` 在执行器运行前盖章完整执行策略——显式升级模式 > 会话覆盖 > 配置默认值,且 `SessionHeader.cwd` > 配置的后备根目录。`SandboxBashExecutor.resolve()` 在 spec 上保留该策略,或为直接的无 agent 调用方提供部署后备值,使 `run()`/`start()` 永不读取可变会话状态。每进程包装事实以返回的 `BashProcess` 为键;`onProcessDone()` 会通过 stderr 分类之外的通道接收 spawn 失败,并在 `done` 结算前给该句柄盖章,因此重叠进程各自保留自己的模式和 runner 方言。
当约束执行器被挂载时,`bash` 公布配对的 `sandbox_permissions` 和 `justification` 字段。schema 暴露完整的封闭升级词汇,因为有效模式是按会话的;执行拒绝任何不严格宽于该调用有效模式的目标。批准在执行之前解析。`allowed-once` 仅将授权模式盖章到该请求上,而 `rejected`、`cancelled`、`unavailable`、缺失的 approval 服务或缺失的 agent 都以各自不同的结果文本失败关闭。授权不持久化。
@@ -117,7 +117,7 @@ fs/web/todo 在进程内执行,因此它们的沙箱语义是各自 seam 层
### 测试
- **单元测试:** 固定平台选择和 profile、结构化 runner 分类(包括只有部分强制执行通知的子进程结果、致命证据、外层 shell 失败,以及前台/后台一致性)、按调用的模式/根目录解析、按进程事实、升级验证和结果、权限 preset fold 和写入透传,以及运行时上下文排序与具体化。
- **单元测试:** 固定平台选择和 profile、直接交接提供方返回的 argv、spawn 层失败、受约束的 `BASH_ENV` 求值顺序、结构化 runner 分类(包括只有部分强制执行通知的子进程结果、带门控的致命证据、子进程退出码 126/127,以及前台/后台一致性)、按调用的模式/根目录解析、按进程事实、升级验证和结果、权限 preset fold 和写入透传,以及运行时上下文排序与具体化。
- **Keyless 真实 runner:** 在提供方和 bash 消费方层面对 bwrap、Landlock 和 Seatbelt 执行真实文件系统效果测试;一个真实 Cordis 上下文通过已交付的 bash 和 fs 工具并发驱动两个项目会话,证明在自身根目录写入成功、在兄弟根目录写入被拒绝。Packed-install 覆盖率证明注册表 launcher 保持可执行。CI 拒绝静默全跳过。
- **With-key:** 以只读模式启动真实 ACP 组合,让模型驱动的 bash 写入命中 runner 的拒绝标记,再通过已授权与被拒绝的 workspace-write 重试驱动 bridge 应答器和磁盘效果;不可用的凭证或 runner 自动跳过。
- **快照:** 固定原子化的当前策略上下文和两个脚本化的 approval 分支。一个真实 ACP 示例场景把会话放在用户主目录下,同时让部署后备根目录指向 `/tmp`,然后固定 workspace-write 运行时上下文消息与一次成功的、由部署选定的变更;这能区分会话根目录解析与进程后备值,而不依赖 runner 特定的拒绝文本。一个模拟 Landlock 部分强制执行行为的 POSIX 提供方会在组装后的应用中固定直接执行 bash `false` 时仍得到普通子进程结果。其他快照以无约束启动,使无关 fixture(测试前置数据)保持平台无关。
@@ -172,20 +172,20 @@ fs/web/todo 在进程内执行,因此它们的沙箱语义是各自 seam 层
- **单一包装的幻觉被有意放弃。**`tools/pre-execute` 包装加提示词约定无法解决沙箱批准——正确的设计需要结构化拒绝、原生 runner 探测、按调用策略承载和一致的跨工具族强制,本设计为此付出了代价。
- **`read-only` 通过后续设计成为跨工具族边界。** 本 Agent Note 最初只交付 bash 强制;[跨工具族 fs 沙箱 Agent Note](2026-07-14-cross-family-fs-sandbox.md) 通过沙箱化的 `ctx.fs` 提供方把同一模式词汇扩展到文件系统工具,并将 mode/root 配置和 `sandbox/mode` 覆盖迁移到 `ctx.sandboxPolicy`(§ 进程内工具)。
- **Windows 没有后端。** 其链槽保留为空——失败关闭,绝不穿透;填充它是延迟阶段。
- **Seatbelt 层级依赖 Apple 已弃用但仍交付的 `sandbox-exec` CLI。** 作为 darwin 的唯一候选,它无需探测即被选中,因此未来移除会在执行时作为 runner 失败分类浮现——重新抛出 `SANDBOX_UNAVAILABLE`,命令从未运行;失败关闭,绝不开放。
- **Seatbelt 层级依赖 Apple 已弃用但仍交付的 `sandbox-exec` CLI。** 作为 darwin 的唯一候选,它无需探测即被选中,因此未来移除会表现为直接 spawn 失败,可执行文件拒绝则通过其致命签名体现——两者都会变为 `SANDBOX_UNAVAILABLE`,且命令绝不会运行;失败关闭,绝不开放。
- **Landlock 约束的完整度取决于运行内核的 ABI。** 报告为 `enforcement: 'partial'` 而非拒绝——这是有意的权衡,使备选在旧内核主机上仍可用。
- **Runner 归因使用带内协议。** 退出状态与 stderr 无法以密码学方式识别写入者,因此受限子进程可以模仿 runner 的致命诊断行和状态,造成可用性或诊断误归因。多项证据的合取与精确通知排除减少了意外匹配;这不是沙箱绕过,因为子进程已经受到限制。
- **launcher 作为注册表依赖到达。** 通过其自身仓库的发布流水线(经审查的 C 源码、原生 CI 构建器、字节固定的发布演练)加上本仓库的版本固定获得信任——真实内核 e2e 测试腿是通过安装字节为行为背书的。
- **模型可能过度请求。** 在没有拒绝依据的情况下升级,或在 `workspace-write` 足够时选择 `danger-full-access`:描述引导且枚举强制阶梯,但人的提示词是实际门控;`approval/asked` 原因使过度请求可审计,且 `prepend` 策略应答器可以自动拒绝部署永远不想要的模式。
- **公布的目标集是静态的,而有效模式是按会话的**(schema 是注册表全局的)——已处于最宽模式的会话仍被提供这些字段。构造上无害:执行时的严格放宽检查(而非枚举)是安全边界——非放宽请求以自身文本失败且不提示任何人。
- **授权的升级不等于可工作的沙箱。** 不可用的后端即使对授权升级到约束模式也仍然失败关闭——在平台没有链或所有探测失败时于 `confine()` 阶段,在未探测的唯一 runner 拒绝时于执行阶段(归类为沙箱失败而非命令失败)——而授权的 `danger-full-access` 运行根本不触及提供方:此时授权(而非探测)是权威。
- **授权的升级不等于可工作的沙箱。** 不可用的后端即使对授权升级到约束模式也仍然失败关闭——平台没有链或所有探测失败时在 `confine()` 阶段失败,所选可执行文件无法启动时通过 spawn 通道失败,已启动的 runner 拒绝时则通过结构化规则失败——而授权的 `danger-full-access` 运行根本不触及提供方:此时授权(而非探测)是权威。
- **运行时上下文历史仅追加。** 策略切换会在保留的历史之后追加一份用于取代先前快照的完整快照,从而保留稳定的系统与对话前缀;状态不变时不添加消息。
- **旧策略快照仍保留在历史中。** 每份完整快照都会明确取代更早的运行时上下文快照,因此回放与压缩(compaction)只需保留最新具体化的消息。
## FAQ
- **一个命令返回了 `[sandbox: file access denied under read-only mode]`——它失败了吗?** 它运行了,内核拒绝了一个文件操作:拒绝是与退出码正交的结果事实。教学禁止绕过它重试;唯一被认可的动作是以升级请求重试同一命令一次。
- **如何区分损坏的沙箱与失败的命令?** 只有当 `runnerFailureRules` 中某一条目同时匹配其可选退出码门控,以及排除整行精确信息性行后的一行致命 stderr 诊断时,runner 失败才会优先于拒绝。前台重新抛出结构化的 `SANDBOX_UNAVAILABLE` 并附带匹配到的致命行;后台任务盖章 `sandbox.runnerFailed` 并渲染自己的标记。Landlock 部分强制执行通知加上普通子进程失败时,仍返回命令结果。
- **如何区分损坏的沙箱与失败的命令?** spawn 提供方 argv 遭拒证明受限启动从未开始。进程启动后,只有当 `runnerFailureRules` 中某一条目同时匹配其可选退出码门控,以及排除整行精确信息性行后的一行致命 stderr 诊断时,runner 失败才会优先于拒绝。前台抛出结构化的 `SANDBOX_UNAVAILABLE`,并附带 spawn 错误或匹配行作为详细信息;后台任务盖章 `sandbox.runnerFailed` 并渲染自己的标记。Landlock 部分强制执行通知加上普通子进程失败时,仍返回命令结果。
- **在没有后端的平台上会发生什么——今天的 Windows?** `confine()` 抛出失败关闭的 `SANDBOX_UNAVAILABLE`,命令永不 spawn;`win32` 是保留的空链,由测试固定为同样失败关闭,直到 Windows runner 填充它(§ 延迟阶段)。
- **`bwrap` 已安装在我的主机上但不可用(禁用了非特权 userns、LSM 拒绝 `mount`)——会发生什么?** 链探测是功能性的——它构建并强制一个真实 profile 而非检查 `--version`——因此存在但不可用的 `bwrap` 探测失败,选择落到注册表安装的 Landlock launcher,结论在提供方生命周期内缓存。
- **沙箱限制网络或进程可见性吗?** 不——`SandboxMode` 仅声称文件操作;bwrap profile 刻意不 unshare pid,没有后端声称网络。网络限制是否成为自己的旋钮留在 § seam 中开放。