From 08f529c57faad9e8bf7cb3881576d0c5fa4b984e Mon Sep 17 00:00:00 2001
From: Takashi Nakayama <tnak@chromium.org>
Date: Tue, 06 Oct 2026 00:02:02 -0700
Subject: [PATCH] ServiceWorker: Drop ServiceWorkerMainResourceHandle for CSP-sandboxed workers

When shared and dedicated worker scripts are received and started, its
PolicyContainerPolicies must be computed and checked to prevent invalid
ServiceWorker from running for the shared/dedicated worker.

This CL ensures the calculation of PolicyContainerPolicies in
DidCreateScriptLoader() and drops ServiceWorkerHandle if the worker is
sandboxed by CSP.

See the bug for details.

Bug: 41478971, 563194341
Change-Id: I8e1df63ea670b10a3bfec73dedd47036ae62dd5e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/8461264
Reviewed-by: Rakina Zata Amni <rakina@chromium.org>
Reviewed-by: Yoshisato Yanagisawa <yyanagisawa@chromium.org>
Commit-Queue: Takashi Nakayama <tnak@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1712040}
---
diff --git a/content/browser/worker_host/dedicated_worker_host.cc b/content/browser/worker_host/dedicated_worker_host.cc
index cf8c8f63..b206e6eb3 100644
--- a/content/browser/worker_host/dedicated_worker_host.cc
+++ b/content/browser/worker_host/dedicated_worker_host.cc
@@ -42,6 +42,7 @@
 #include "content/browser/worker_host/dedicated_worker_service_impl.h"
 #include "content/browser/worker_host/worker_script_fetcher.h"
 #include "content/browser/worker_host/worker_util.h"
+#include "content/common/features.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/network_service_util.h"
@@ -227,8 +228,8 @@
     mojo::PendingReceiver<blink::mojom::LockManager> receiver) {
   GetStoragePartitionImpl()->BindLockManager(
       GetWorkerStorageKey(), GetToken().value(), std::move(receiver));
-  GetStoragePartitionImpl()->GetLockManager()->AddLockObserver(GetToken().value(),
-                                                            this);
+  GetStoragePartitionImpl()->GetLockManager()->AddLockObserver(
+      GetToken().value(), this);
 }
 
 bool DedicatedWorkerHost::OnLockContention() {
@@ -546,7 +547,6 @@
     worker_client_security_state_->cross_origin_embedder_policy =
         result->main_script_load_params->response_head->parsed_headers
             ->cross_origin_embedder_policy;
-
   }
 
   // The worker global scope's document isolation policy is the same as its
@@ -609,6 +609,18 @@
   auto policy_container_host = base::MakeRefCounted<PolicyContainerHost>(
       std::move(result->policy_container_policies));
 
+  // A worker sandboxed without `allow-same-origin` has an opaque origin and
+  // is not eligible to use service workers (mirroring
+  // `NavigationRequest::CommitNavigation()`).
+  if (base::FeatureList::IsEnabled(
+          features::kServiceWorkerDropHandleForCSPSandboxedWorker) &&
+      service_worker_handle_ &&
+      (policy_container_host->policies().sandbox_flags &
+       network::mojom::WebSandboxFlags::kOrigin) ==
+          network::mojom::WebSandboxFlags::kOrigin) {
+    service_worker_handle_.reset();
+  }
+
   blink::mojom::ServiceWorkerContainerInfoForClientPtr container_info;
   blink::mojom::ControllerServiceWorkerInfoPtr controller;
   if (GetServiceWorkerClient()) {
diff --git a/content/browser/worker_host/dedicated_worker_host.h b/content/browser/worker_host/dedicated_worker_host.h
index 21a3f05..5bb43195 100644
--- a/content/browser/worker_host/dedicated_worker_host.h
+++ b/content/browser/worker_host/dedicated_worker_host.h
@@ -301,6 +301,8 @@
   }
 
  private:
+  friend class DedicatedWorkerServiceImplTest;
+
   // RenderProcessHostObserver:
   void RenderProcessExited(RenderProcessHost* render_process_host,
                            const ChildProcessTerminationInfo& info) override;
diff --git a/content/browser/worker_host/shared_worker_host.cc b/content/browser/worker_host/shared_worker_host.cc
index 4d2e7f7..dcbf9f96 100644
--- a/content/browser/worker_host/shared_worker_host.cc
+++ b/content/browser/worker_host/shared_worker_host.cc
@@ -317,12 +317,18 @@
           /*frame_tree_node=*/std::nullopt);
     }
 
-    // https://html.spec.whatwg.org/C/#creating-a-policy-container-from-a-fetch-response
-    // This does not parse the referrer policy, which will be
-    // updated in `SharedWorkerGlobalScope::Initialize()`.
-    PolicyContainerPolicies policies(
-        result.final_response_url,
-        result.main_script_load_params->response_head.get(), nullptr);
+    PolicyContainerPolicies policies;
+    if (base::FeatureList::IsEnabled(
+            features::kServiceWorkerDropHandleForCSPSandboxedWorker)) {
+      policies = std::move(result.policy_container_policies);
+    } else {
+      // https://html.spec.whatwg.org/C/#creating-a-policy-container-from-a-fetch-response
+      // This does not parse the referrer policy, which will be updated in
+      // `SharedWorkerGlobalScope::Initialize()`.
+      policies = PolicyContainerPolicies(
+          result.final_response_url,
+          result.main_script_load_params->response_head.get(), nullptr);
+    }
 
     // A worker context can only be secure if its creator also is.
     if (!creator_policy_container_host_->policies().is_web_secure_context) {
@@ -433,9 +439,22 @@
   result.subresource_loader_factories->set_bypass_redirect_checks(
       bypass_redirect_checks);
 
+  // A worker sandboxed without `allow-same-origin` has an opaque origin and
+  // is not eligible to use service workers (mirroring
+  // `NavigationRequest::CommitNavigation()`).
+  if (base::FeatureList::IsEnabled(
+          features::kServiceWorkerDropHandleForCSPSandboxedWorker) &&
+      service_worker_handle_ &&
+      (policy_container_host->policies().sandbox_flags &
+       network::mojom::WebSandboxFlags::kOrigin) ==
+          network::mojom::WebSandboxFlags::kOrigin) {
+    service_worker_handle_.reset();
+  }
+
   blink::mojom::ServiceWorkerContainerInfoForClientPtr container_info;
   blink::mojom::ControllerServiceWorkerInfoPtr controller;
-  if (service_worker_handle_->service_worker_client()) {
+  if (service_worker_handle_ &&
+      service_worker_handle_->service_worker_client()) {
     mojo::PendingRemote<network::mojom::CrossOriginEmbedderPolicyReporter>
         coep_reporter;
     if (coep_reporter_) {
@@ -450,7 +469,10 @@
         service_worker_handle_->scoped_service_worker_client()
             ->CommitResponseAndRelease(
                 /*rfh_id=*/std::nullopt,
-                std::move(result.policy_container_policies),
+                base::FeatureList::IsEnabled(
+                    features::kServiceWorkerDropHandleForCSPSandboxedWorker)
+                    ? policy_container_host->policies()
+                    : result.policy_container_policies,
                 std::move(coep_reporter), std::move(dip_reporter),
                 ukm_source_id());
   }
@@ -502,7 +524,8 @@
       instance_.DoesRequireCrossSiteRequestForCookies(),
       std::move(coep_reporting_observer), std::move(dip_reporting_observer),
       cross_origin_isolated);
-  if (service_worker_handle_->service_worker_client()) {
+  if (service_worker_handle_ &&
+      service_worker_handle_->service_worker_client()) {
     service_worker_handle_->service_worker_client()->SetContainerReady();
   }
 
diff --git a/content/browser/worker_host/worker_script_fetcher.cc b/content/browser/worker_host/worker_script_fetcher.cc
index 522d8c1..77f5160 100644
--- a/content/browser/worker_host/worker_script_fetcher.cc
+++ b/content/browser/worker_host/worker_script_fetcher.cc
@@ -31,6 +31,7 @@
 #include "content/browser/worker_host/network_restrictions_worker_throttle.h"
 #include "content/browser/worker_host/worker_script_loader.h"
 #include "content/browser/worker_host/worker_script_loader_factory.h"
+#include "content/common/features.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/child_process_host.h"
@@ -127,6 +128,28 @@
       /*is_for_worker_script=*/true);
 }
 
+// Build `PolicyContainerPolicies` from the worker script response headers or
+// inherit from the creator for local schemes.
+PolicyContainerPolicies ComputePolicyContainerPoliciesForWorker(
+    const GURL& final_response_url,
+    network::mojom::URLResponseHead* response_head,
+    const PolicyContainerPolicies* creator_policies) {
+  PolicyContainerPolicies policies;
+  if (base::FeatureList::IsEnabled(
+          features::kServiceWorkerDropHandleForCSPSandboxedWorker)) {
+    if (final_response_url.SchemeIsLocal() && creator_policies) {
+      policies = creator_policies->Clone();
+    } else if (response_head && response_head->parsed_headers) {
+      policies =
+          PolicyContainerPolicies(final_response_url, response_head, nullptr);
+    }
+  }
+  policies.connection_allowlists = GetConnectionAllowlistsForWorker(
+      final_response_url, response_head, creator_policies,
+      final_response_url.SchemeIsLocal());
+  return policies;
+}
+
 void DidCreateScriptLoader(
     WorkerScriptFetcher::CompletionCallback callback,
     std::unique_ptr<blink::PendingURLLoaderFactoryBundle>
@@ -176,14 +199,12 @@
 
   // The load succeeded iff `main_script_load_params` is not nullptr.
   if (main_script_load_params) {
-    // TODO(crbug.com/41478971): Pass the PolicyContainerPolicies. It can
-    // be built from the
-    // `main_script_load_params.response_head->parsed_headers`.
-    PolicyContainerPolicies policies;
-    policies.connection_allowlists = GetConnectionAllowlistsForWorker(
+    // Note: Unlike in the spec, the referrer policy will be lazily calculated
+    // by the renderer in `(Shared/Dedicated)WorkerGlobalScope::Initialize()`.
+    // https://html.spec.whatwg.org/C/#creating-a-policy-container-from-a-fetch-response
+    PolicyContainerPolicies policies = ComputePolicyContainerPoliciesForWorker(
         final_response_url, main_script_load_params->response_head.get(),
-        base::OptionalToPtr(creator_policies),
-        final_response_url.SchemeIsLocal());
+        base::OptionalToPtr(creator_policies));
 
     std::move(callback).Run(std::make_optional<WorkerScriptFetcherResult>(
         std::move(subresource_loader_factories),
@@ -713,6 +734,16 @@
   return initial_request_url;
 }
 
+// static
+PolicyContainerPolicies
+WorkerScriptFetcher::ComputePolicyContainerPoliciesForTesting(
+    const GURL& final_response_url,
+    network::mojom::URLResponseHead* response_head,
+    const PolicyContainerPolicies* creator_policies) {
+  return ComputePolicyContainerPoliciesForWorker(
+      final_response_url, response_head, creator_policies);
+}
+
 WorkerScriptFetcher::WorkerScriptFetcher(
     std::unique_ptr<WorkerScriptLoaderFactory> script_loader_factory,
     std::unique_ptr<network::ResourceRequest> resource_request,
diff --git a/content/browser/worker_host/worker_script_fetcher.h b/content/browser/worker_host/worker_script_fetcher.h
index 0c20572..de982a15 100644
--- a/content/browser/worker_host/worker_script_fetcher.h
+++ b/content/browser/worker_host/worker_script_fetcher.h
@@ -176,6 +176,12 @@
       const GURL& initial_request_url,
       blink::mojom::WorkerMainScriptLoadParams* main_script_load_params);
 
+  CONTENT_EXPORT static PolicyContainerPolicies
+  ComputePolicyContainerPoliciesForTesting(
+      const GURL& final_response_url,
+      network::mojom::URLResponseHead* response_head,
+      const PolicyContainerPolicies* creator_policies);
+
  private:
   // Callback invoked by this instance when the load ends, successfully or not.
   //
diff --git a/content/common/features.cc b/content/common/features.cc
index 8d0431b0..0a49092b0 100644
--- a/content/common/features.cc
+++ b/content/common/features.cc
@@ -755,6 +755,10 @@
         &kServiceWorkerBypassFetchHandlerHashStrings,
         "script_checksum_to_bypass", ""};
 
+// Killswitch for crbug.com/563194341
+BASE_FEATURE(kServiceWorkerDropHandleForCSPSandboxedWorker,
+             base::FEATURE_ENABLED_BY_DEFAULT);
+
 // (crbug.com/41411856): When enabled, the srcdoc iframes are controlled by the
 // same service worker that controls their parent.
 BASE_FEATURE(kServiceWorkerSrcdocSupport, base::FEATURE_ENABLED_BY_DEFAULT);
diff --git a/content/common/features.h b/content/common/features.h
index 8cddb975..76487c0d 100644
--- a/content/common/features.h
+++ b/content/common/features.h
@@ -233,6 +233,8 @@
     kServiceWorkerBypassFetchHandlerHashStrings);
 CONTENT_EXPORT extern const base::FeatureParam<std::string>
     kServiceWorkerBypassFetchHandlerBypassedHashStrings;
+CONTENT_EXPORT BASE_DECLARE_FEATURE(
+    kServiceWorkerDropHandleForCSPSandboxedWorker);
 CONTENT_EXPORT BASE_DECLARE_FEATURE(kServiceWorkerSrcdocSupport);
 CONTENT_EXPORT BASE_DECLARE_FEATURE(kServiceWorkerStaticRouterCORPCheck);
 CONTENT_EXPORT BASE_DECLARE_FEATURE(kServiceWorkerStaticRouterOpaqueCheck);
diff --git a/content/browser/worker_host/dedicated_worker_service_impl_unittest.cc b/content/browser/worker_host/dedicated_worker_service_impl_unittest.cc
index d4e3f17e..6bafa74 100644
--- a/content/browser/worker_host/dedicated_worker_service_impl_unittest.cc
+++ b/content/browser/worker_host/dedicated_worker_service_impl_unittest.cc
@@ -19,6 +19,7 @@
 #include "content/browser/storage_partition_impl.h"
 #include "content/browser/worker_host/dedicated_worker_host.h"
 #include "content/browser/worker_host/dedicated_worker_host_factory_impl.h"
+#include "content/browser/worker_host/worker_script_fetcher.h"
 #include "content/common/content_navigation_policy.h"
 #include "content/public/browser/back_forward_cache.h"
 #include "content/public/browser/storage_partition.h"
@@ -36,6 +37,8 @@
 #include "net/storage_access_api/status.h"
 #include "services/network/public/cpp/constants.h"
 #include "services/network/public/mojom/client_security_state.mojom.h"
+#include "services/network/public/mojom/parsed_headers.mojom.h"
+#include "services/network/public/mojom/url_response_head.mojom.h"
 #include "third_party/blink/public/common/storage_key/storage_key.h"
 #include "third_party/blink/public/common/tokens/tokens.h"
 #include "third_party/blink/public/common/tokens/tokens_mojom_traits.h"
@@ -71,7 +74,7 @@
     // ignored.
     auto* ancestor_rfh =
         RenderFrameHostImpl::FromID(ancestor_render_frame_host_id);
-    auto coep_reporter = std::make_unique<CrossOriginEmbedderPolicyReporter>(
+    coep_reporter_ = std::make_unique<CrossOriginEmbedderPolicyReporter>(
         ancestor_rfh->GetStoragePartition()->GetWeakPtr(), GURL(), std::nullopt,
         std::nullopt, base::UnguessableToken::Create(),
         net::NetworkAnonymizationKey());
@@ -82,7 +85,7 @@
         blink::StorageKey::CreateFirstParty(origin),
         net::IsolationInfo::CreateTransient(/*nonce=*/std::nullopt),
         network::mojom::ClientSecurityState::New(), PolicyContainerPolicies(),
-        coep_reporter->GetWeakPtr(), network::GetTestNetworkRestrictionsId());
+        coep_reporter_->GetWeakPtr(), network::GetTestNetworkRestrictionsId());
 
     auto fetch_client_settings_object =
         blink::mojom::FetchClientSettingsObject::New();
@@ -131,6 +134,7 @@
   void OnScriptLoadStartFailed() override {}
 
  private:
+  std::unique_ptr<CrossOriginEmbedderPolicyReporter> coep_reporter_;
   mojo::Receiver<blink::mojom::DedicatedWorkerHostFactoryClient> receiver_{
       this};
 
@@ -141,8 +145,7 @@
   mojo::Remote<blink::mojom::DedicatedWorkerHost> remote_host_;
 };
 
-class DedicatedWorkerServiceImplTest
-    : public RenderViewHostImplTestHarness {
+class DedicatedWorkerServiceImplTest : public RenderViewHostImplTestHarness {
  public:
   DedicatedWorkerServiceImplTest() = default;
   ~DedicatedWorkerServiceImplTest() override = default;
@@ -182,6 +185,40 @@
             ->GetDedicatedWorkerService());
   }
 
+  void DidStartScriptLoad(DedicatedWorkerHost* host,
+                          const GURL& final_response_url,
+                          network::mojom::URLResponseHeadPtr response_head) {
+    auto main_script_load_params =
+        blink::mojom::WorkerMainScriptLoadParams::New();
+    if (!response_head) {
+      response_head = network::mojom::URLResponseHead::New();
+    }
+    if (!response_head->parsed_headers) {
+      response_head->parsed_headers = network::mojom::ParsedHeaders::New();
+    }
+    main_script_load_params->response_head = std::move(response_head);
+    mojo::ScopedDataPipeProducerHandle producer_handle;
+    mojo::ScopedDataPipeConsumerHandle consumer_handle;
+    ASSERT_EQ(MOJO_RESULT_OK,
+              mojo::CreateDataPipe(nullptr, producer_handle, consumer_handle));
+    main_script_load_params->response_body = std::move(consumer_handle);
+    auto subresource_loader_factories =
+        std::make_unique<blink::PendingURLLoaderFactoryBundle>();
+
+    PolicyContainerPolicies policies =
+        WorkerScriptFetcher::ComputePolicyContainerPoliciesForTesting(
+            final_response_url, main_script_load_params->response_head.get(),
+            /*creator_policies=*/nullptr);
+    host->DidStartScriptLoad(
+        WorkerScriptFetcherResult(std::move(subresource_loader_factories),
+                                  std::move(main_script_load_params),
+                                  std::move(policies), final_response_url));
+  }
+
+  bool HasServiceWorkerHandle(DedicatedWorkerHost* host) const {
+    return host->service_worker_handle_ != nullptr;
+  }
+
  private:
   std::unique_ptr<TestBrowserContext> browser_context_;
 };
@@ -219,16 +256,18 @@
             .second;
     DCHECK(inserted);
 
-    if (on_worker_event_callback_)
+    if (on_worker_event_callback_) {
       std::move(on_worker_event_callback_).Run();
+    }
   }
   void OnBeforeWorkerDestroyed(const blink::DedicatedWorkerToken& token,
                                DedicatedWorkerCreator creator) override {
     size_t removed = dedicated_worker_infos_.erase(token);
     DCHECK_EQ(removed, 1u);
 
-    if (on_worker_event_callback_)
+    if (on_worker_event_callback_) {
       std::move(on_worker_event_callback_).Run();
+    }
... (file diff truncated)

diff --git a/content/browser/worker_host/dedicated_worker_service_impl_unittest.cc b/content/browser/worker_host/dedicated_worker_service_impl_unittest.cc
index d4e3f17e..6bafa74 100644
--- a/content/browser/worker_host/dedicated_worker_service_impl_unittest.cc
+++ b/content/browser/worker_host/dedicated_worker_service_impl_unittest.cc
@@ -19,6 +19,7 @@
 #include "content/browser/storage_partition_impl.h"
 #include "content/browser/worker_host/dedicated_worker_host.h"
 #include "content/browser/worker_host/dedicated_worker_host_factory_impl.h"
+#include "content/browser/worker_host/worker_script_fetcher.h"
 #include "content/common/content_navigation_policy.h"
 #include "content/public/browser/back_forward_cache.h"
 #include "content/public/browser/storage_partition.h"
@@ -36,6 +37,8 @@
 #include "net/storage_access_api/status.h"
 #include "services/network/public/cpp/constants.h"
 #include "services/network/public/mojom/client_security_state.mojom.h"
+#include "services/network/public/mojom/parsed_headers.mojom.h"
+#include "services/network/public/mojom/url_response_head.mojom.h"
 #include "third_party/blink/public/common/storage_key/storage_key.h"
 #include "third_party/blink/public/common/tokens/tokens.h"
 #include "third_party/blink/public/common/tokens/tokens_mojom_traits.h"
@@ -71,7 +74,7 @@
     // ignored.
     auto* ancestor_rfh =
         RenderFrameHostImpl::FromID(ancestor_render_frame_host_id);
-    auto coep_reporter = std::make_unique<CrossOriginEmbedderPolicyReporter>(
+    coep_reporter_ = std::make_unique<CrossOriginEmbedderPolicyReporter>(
         ancestor_rfh->GetStoragePartition()->GetWeakPtr(), GURL(), std::nullopt,
         std::nullopt, base::UnguessableToken::Create(),
         net::NetworkAnonymizationKey());
@@ -82,7 +85,7 @@
         blink::StorageKey::CreateFirstParty(origin),
         net::IsolationInfo::CreateTransient(/*nonce=*/std::nullopt),
         network::mojom::ClientSecurityState::New(), PolicyContainerPolicies(),
-        coep_reporter->GetWeakPtr(), network::GetTestNetworkRestrictionsId());
+        coep_reporter_->GetWeakPtr(), network::GetTestNetworkRestrictionsId());
 
     auto fetch_client_settings_object =
         blink::mojom::FetchClientSettingsObject::New();
@@ -131,6 +134,7 @@
   void OnScriptLoadStartFailed() override {}
 
  private:
+  std::unique_ptr<CrossOriginEmbedderPolicyReporter> coep_reporter_;
   mojo::Receiver<blink::mojom::DedicatedWorkerHostFactoryClient> receiver_{
       this};
 
@@ -141,8 +145,7 @@
   mojo::Remote<blink::mojom::DedicatedWorkerHost> remote_host_;
 };
 
-class DedicatedWorkerServiceImplTest
-    : public RenderViewHostImplTestHarness {
+class DedicatedWorkerServiceImplTest : public RenderViewHostImplTestHarness {
  public:
   DedicatedWorkerServiceImplTest() = default;
   ~DedicatedWorkerServiceImplTest() override = default;
@@ -182,6 +185,40 @@
             ->GetDedicatedWorkerService());
   }
 
+  void DidStartScriptLoad(DedicatedWorkerHost* host,
+                          const GURL& final_response_url,
+                          network::mojom::URLResponseHeadPtr response_head) {
+    auto main_script_load_params =
+        blink::mojom::WorkerMainScriptLoadParams::New();
+    if (!response_head) {
+      response_head = network::mojom::URLResponseHead::New();
+    }
+    if (!response_head->parsed_headers) {
+      response_head->parsed_headers = network::mojom::ParsedHeaders::New();
+    }
+    main_script_load_params->response_head = std::move(response_head);
+    mojo::ScopedDataPipeProducerHandle producer_handle;
+    mojo::ScopedDataPipeConsumerHandle consumer_handle;
+    ASSERT_EQ(MOJO_RESULT_OK,
+              mojo::CreateDataPipe(nullptr, producer_handle, consumer_handle));
+    main_script_load_params->response_body = std::move(consumer_handle);
+    auto subresource_loader_factories =
+        std::make_unique<blink::PendingURLLoaderFactoryBundle>();
+
+    PolicyContainerPolicies policies =
+        WorkerScriptFetcher::ComputePolicyContainerPoliciesForTesting(
+            final_response_url, main_script_load_params->response_head.get(),
+            /*creator_policies=*/nullptr);
+    host->DidStartScriptLoad(
+        WorkerScriptFetcherResult(std::move(subresource_loader_factories),
+                                  std::move(main_script_load_params),
+                                  std::move(policies), final_response_url));
+  }
+
+  bool HasServiceWorkerHandle(DedicatedWorkerHost* host) const {
+    return host->service_worker_handle_ != nullptr;
+  }
+
  private:
   std::unique_ptr<TestBrowserContext> browser_context_;
 };
@@ -219,16 +256,18 @@
             .second;
     DCHECK(inserted);
 
-    if (on_worker_event_callback_)
+    if (on_worker_event_callback_) {
       std::move(on_worker_event_callback_).Run();
+    }
   }
   void OnBeforeWorkerDestroyed(const blink::DedicatedWorkerToken& token,
                                DedicatedWorkerCreator creator) override {
     size_t removed = dedicated_worker_infos_.erase(token);
     DCHECK_EQ(removed, 1u);
 
-    if (on_worker_event_callback_)
+    if (on_worker_event_callback_) {
       std::move(on_worker_event_callback_).Run();
+    }
   }
   void OnFinalResponseURLDetermined(const blink::DedicatedWorkerToken& token,
                                     const GURL& url) override {}
@@ -852,4 +891,52 @@
   host->CreateBlobUrlStoreProvider(remote.BindNewPipeAndPassReceiver());
   EXPECT_TRUE(remote.is_bound());
 }
+
+// Tests that DedicatedWorkerHost::DidStartScriptLoad drops the
+// ServiceWorkerMainResourceHandle when the worker script response has a CSP
+// sandbox directive without allow-same-origin.
+TEST_F(DedicatedWorkerServiceImplTest,
+       ServiceWorkerHandleDroppedWhenCSPSandboxed) {
+  TestDedicatedWorkerServiceObserver observer;
+  base::ScopedObservation<DedicatedWorkerService,
+                          DedicatedWorkerService::Observer>
+      scoped_observation(&observer);
+  scoped_observation.Observe(GetDedicatedWorkerService());
+
+  const GURL kUrl("https://example.com/");
+  std::unique_ptr<TestWebContents> web_contents = CreateWebContents(kUrl);
+  TestRenderFrameHost* render_frame_host = web_contents->GetPrimaryMainFrame();
+  const ChildProcessId render_process_host_id =
+      render_frame_host->GetProcess()->GetID();
+  const auto origin = url::Origin::Create(kUrl);
+  auto mock_dedicated_worker = std::make_unique<MockDedicatedWorker>(
+      render_process_host_id, render_frame_host->GetGlobalId(), origin);
+  observer.RunUntilWorkerEvent();
+  ASSERT_EQ(observer.dedicated_worker_infos().size(), 1u);
+  const blink::DedicatedWorkerToken worker_token =
+      observer.dedicated_worker_infos().begin()->first;
+  DedicatedWorkerHost* host =
+      GetDedicatedWorkerServiceImpl()->GetDedicatedWorkerHostFromToken(
+          worker_token);
+  ASSERT_TRUE(host);
+  EXPECT_TRUE(HasServiceWorkerHandle(host));
+
+  // Simulate receiving a worker script response with `Content-Security-Policy:
+  // sandbox` (which sets `WebSandboxFlags::kOrigin`).
+  auto response_head = network::mojom::URLResponseHead::New();
+  response_head->parsed_headers = network::mojom::ParsedHeaders::New();
+  auto csp = network::mojom::ContentSecurityPolicy::New();
+  csp->self_origin = network::mojom::CSPSource::New();
+  csp->header = network::mojom::ContentSecurityPolicyHeader::New();
+  csp->sandbox = network::mojom::WebSandboxFlags::kOrigin;
+  response_head->parsed_headers->content_security_policy.push_back(
+      std::move(csp));
+
+  // Verify that the service worker handle is dropped when script load starts.
+  DidStartScriptLoad(host, GURL("https://example.com/worker.js"),
+                     std::move(response_head));
+  EXPECT_FALSE(HasServiceWorkerHandle(host));
+  EXPECT_FALSE(host->GetServiceWorkerClient());
+}
+
 }  // namespace content
diff --git a/content/browser/worker_host/shared_worker_host_unittest.cc b/content/browser/worker_host/shared_worker_host_unittest.cc
index f3b491c..687761e 100644
--- a/content/browser/worker_host/shared_worker_host_unittest.cc
+++ b/content/browser/worker_host/shared_worker_host_unittest.cc
@@ -169,22 +169,25 @@
     host->SetServiceWorkerHandle(std::move(service_worker_handle));
 
     TestContentBrowserClient client;
-    host->Start(std::move(factory),
-                blink::mojom::FetchClientSettingsObject::New(
-                    []() {
-                      auto policies =
-                          blink::mojom::PolicyContainerPolicies::New();
-                      policies->referrer_policy =
-                          network::mojom::ReferrerPolicy::kDefault;
-                      return policies;
-                    }(),
-                    /*outgoing_referrer=*/GURL(),
-                    blink::mojom::InsecureRequestsPolicy::kDoNotUpgrade),
-                &client,
-                WorkerScriptFetcherResult(
-                    std::move(subresource_loader_factories),
-                    std::move(main_script_load_params),
-                    PolicyContainerPolicies(), final_response_url));
+    PolicyContainerPolicies policies =
+        WorkerScriptFetcher::ComputePolicyContainerPoliciesForTesting(
+            final_response_url, main_script_load_params->response_head.get(),
+            /*creator_policies=*/nullptr);
+    host->Start(
+        std::move(factory),
+        blink::mojom::FetchClientSettingsObject::New(
+            []() {
+              auto policies = blink::mojom::PolicyContainerPolicies::New();
+              policies->referrer_policy =
+                  network::mojom::ReferrerPolicy::kDefault;
+              return policies;
+            }(),
+            /*outgoing_referrer=*/GURL(),
+            blink::mojom::InsecureRequestsPolicy::kDoNotUpgrade),
+        &client,
+        WorkerScriptFetcherResult(std::move(subresource_loader_factories),
+                                  std::move(main_script_load_params),
+                                  std::move(policies), final_response_url));
   }
 
   MessagePortChannel AddClient(
@@ -201,6 +204,10 @@
     return local_port;
   }
 
+  bool HasServiceWorkerHandle(SharedWorkerHost* host) const {
+    return host->service_worker_handle_ != nullptr;
+  }
+
   void RunNormalTest(bool extended_lifetime) {
     base::WeakPtr<SharedWorkerHost> host = CreateHostWithExtendedLifetime(
         /*extended_lifetime=*/extended_lifetime);
@@ -771,4 +778,24 @@
             host_none->GetNetworkAnonymizationKey());
 }
 
+TEST_F(SharedWorkerHostTest, ServiceWorkerHandleDroppedWhenCSPSandboxed) {
+  base::WeakPtr<SharedWorkerHost> host = CreateHost();
+  mojo::PendingRemote<blink::mojom::SharedWorkerFactory> factory;
+  MockSharedWorkerFactory factory_impl(
+      factory.InitWithNewPipeAndPassReceiver());
+
+  auto response_head = network::mojom::URLResponseHead::New();
+  response_head->parsed_headers = network::mojom::ParsedHeaders::New();
+  auto csp = network::mojom::ContentSecurityPolicy::New();
+  csp->self_origin = network::mojom::CSPSource::New();
+  csp->header = network::mojom::ContentSecurityPolicyHeader::New();
+  csp->sandbox = network::mojom::WebSandboxFlags::kOrigin;
+  response_head->parsed_headers->content_security_policy.push_back(
+      std::move(csp));
+
+  StartWorker(host.get(), std::move(factory),
+              GURL("https://www.example.com/w.js"), std::move(response_head));
+  EXPECT_FALSE(HasServiceWorkerHandle(host.get()));
+}
+
 }  // namespace content
diff --git a/content/browser/worker_host/worker_script_fetcher_unittest.cc b/content/browser/worker_host/worker_script_fetcher_unittest.cc
index b32dc0b..c86dcb8 100644
--- a/content/browser/worker_host/worker_script_fetcher_unittest.cc
+++ b/content/browser/worker_host/worker_script_fetcher_unittest.cc
@@ -6,6 +6,8 @@
 
 #include <vector>
 
+#include "base/test/scoped_feature_list.h"
+#include "content/common/features.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/blink/public/mojom/worker/worker_main_script_load_params.mojom.h"
 #include "url/gurl.h"
@@ -94,4 +96,58 @@
   }
 }
 
+TEST(WorkerScriptFetcherTest, ComputePolicyContainerPolicies_NetworkResponse) {
+  auto response_head = network::mojom::URLResponseHead::New();
+  response_head->parsed_headers = network::mojom::ParsedHeaders::New();
+  auto csp = network::mojom::ContentSecurityPolicy::New();
+  csp->self_origin = network::mojom::CSPSource::New();
+  csp->header = network::mojom::ContentSecurityPolicyHeader::New();
+  csp->sandbox = network::mojom::WebSandboxFlags::kOrigin;
+  response_head->parsed_headers->content_security_policy.push_back(
+      std::move(csp));
+
+  PolicyContainerPolicies policies =
+      WorkerScriptFetcher::ComputePolicyContainerPoliciesForTesting(
+          GURL("https://example.com/worker.js"), response_head.get(),
+          /*creator_policies=*/nullptr);
+  EXPECT_EQ(network::mojom::WebSandboxFlags::kOrigin,
+            policies.sandbox_flags & network::mojom::WebSandboxFlags::kOrigin);
+}
+
+TEST(WorkerScriptFetcherTest, ComputePolicyContainerPolicies_LocalScheme) {
+  auto response_head = network::mojom::URLResponseHead::New();
+  response_head->parsed_headers = network::mojom::ParsedHeaders::New();
+
+  PolicyContainerPolicies creator_policies;
+  creator_policies.sandbox_flags = network::mojom::WebSandboxFlags::kOrigin;
+
+  PolicyContainerPolicies policies =
+      WorkerScriptFetcher::ComputePolicyContainerPoliciesForTesting(
+          GURL("blob:https://example.com/uuid"), response_head.get(),
+          &creator_policies);
... (truncated)