core: tighten unified exec sandbox setup

Refine unified exec sandbox initialization while preserving the requested process workdir.

Co-authored-by: Codex <noreply@openai.com>

codex-rs/core/src/tools/runtimes/unified_exec.rs

@@ -216,10 +216,6 @@ impl Approvable<UnifiedExecRequest> for UnifiedExecRuntime<'_> {
 }
 
 impl<'a> ToolRuntime<UnifiedExecRequest, UnifiedExecProcess> for UnifiedExecRuntime<'a> {
-    fn sandbox_cwd<'b>(&self, req: &'b UnifiedExecRequest) -> Option<&'b AbsolutePathBuf> {
-        Some(&req.cwd)
-    }
-
     fn network_approval_spec(
         &self,
         req: &UnifiedExecRequest,
@@ -361,7 +357,10 @@ impl<'a> ToolRuntime<UnifiedExecRequest, UnifiedExecProcess> for UnifiedExecRunt
 mod tests {
     use super::*;
     use crate::exec::DEFAULT_EXEC_COMMAND_TIMEOUT_MS;
+    use crate::tools::sandboxing::ToolRuntime;
+    use codex_exec_server::Environment;
     use std::time::Duration;
+    use tempfile::tempdir;
 
     #[test]
     fn unified_exec_options_combines_default_timeout_with_network_denial_cancellation() {
@@ -384,4 +383,35 @@ mod tests {
             other => panic!("expected timeout-or-cancellation expiration, got {other:?}"),
         }
     }
+
+    #[tokio::test]
+    async fn unified_exec_keeps_sandbox_policy_anchored_to_turn_cwd() {
+        let dir = tempdir().expect("create temp dir");
+        let cwd = AbsolutePathBuf::try_from(dir.path().to_path_buf()).expect("absolute temp dir");
+        let manager = UnifiedExecProcessManager::default();
+        let runtime = UnifiedExecRuntime::new(&manager, UnifiedExecShellMode::Direct);
+        let request = UnifiedExecRequest {
+            command: vec!["pwd".to_string()],
+            hook_command: "pwd".to_string(),
+            process_id: 1000,
+            cwd,
+            environment: Arc::new(Environment::default_for_tests()),
+            env: HashMap::new(),
+            exec_server_env_config: None,
+            explicit_env_overrides: HashMap::new(),
+            network: None,
+            tty: false,
+            sandbox_permissions: SandboxPermissions::UseDefault,
+            additional_permissions: None,
+            #[cfg(unix)]
+            additional_permissions_preapproved: false,
+            justification: None,
+            exec_approval_requirement: ExecApprovalRequirement::Skip {
+                bypass_sandbox: false,
+                proposed_execpolicy_amendment: None,
+            },
+        };
+
+        assert_eq!(runtime.sandbox_cwd(&request), None);
+    }
 }

codex-rs/core/src/unified_exec/process_manager.rs

@@ -1010,7 +1010,9 @@ impl UnifiedExecProcessManager {
                 approval_policy: context.turn.approval_policy.value(),
                 permission_profile: context.turn.permission_profile(),
                 file_system_sandbox_policy: &file_system_sandbox_policy,
-                sandbox_cwd: cwd.as_path(),
+                // The process cwd may be model-controlled, but policy resolution
+                // must stay anchored to the trusted turn cwd.
+                sandbox_cwd: context.turn.cwd.as_path(),
                 sandbox_permissions: if request.additional_permissions_preapproved {
                     crate::sandboxing::SandboxPermissions::UseDefault
                 } else {