Fix web accessible resource checks in ShouldAllowOpenURL for M55

chrome/browser/extensions/chrome_content_browser_client_extensions_part.cc

Index: chrome/browser/extensions/chrome_content_browser_client_extensions_part.cc
diff --git a/chrome/browser/extensions/chrome_content_browser_client_extensions_part.cc b/chrome/browser/extensions/chrome_content_browser_client_extensions_part.cc
index 315fe0fd68b3d7c6628f1d74f625d7c68b820939..728147c04dc9019959591529c1ae7525ddea374f 100644
--- a/chrome/browser/extensions/chrome_content_browser_client_extensions_part.cc
+++ b/chrome/browser/extensions/chrome_content_browser_client_extensions_part.cc
@@ -9,6 +9,7 @@
 #include <set>
 
 #include "base/command_line.h"
+#include "base/metrics/histogram_macros.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_web_ui.h"
@@ -22,6 +23,7 @@
 #include "chrome/common/chrome_constants.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/extensions/extension_process_policy.h"
+#include "chrome/common/url_constants.h"
 #include "components/guest_view/browser/guest_view_message_filter.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/browser_url_handler.h"
@@ -32,6 +34,7 @@
 #include "content/public/browser/vpn_service_proxy.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/common/content_switches.h"
+#include "content/public/common/url_constants.h"
 #include "extensions/browser/api/web_request/web_request_api.h"
 #include "extensions/browser/api/web_request/web_request_api_helpers.h"
 #include "extensions/browser/bad_message.h"
@@ -82,6 +85,20 @@ enum RenderProcessHostPrivilege {
   PRIV_EXTENSION,
 };
 
+// Specifies reasons why web-accessible resource checks in ShouldAllowOpenURL
+// might fail.
+//
+// This enum backs an UMA histogram.  The order of existing values
+// should not be changed, and new values should only be added before
+// FAILURE_LAST.
+enum ShouldAllowOpenURLFailureReason {
+  FAILURE_FILE_SYSTEM_URL = 0,
+  FAILURE_BLOB_URL,
+  FAILURE_SCHEME_NOT_HTTP_OR_HTTPS_OR_EXTENSION,
+  FAILURE_RESOURCE_NOT_WEB_ACCESSIBLE,
+  FAILURE_LAST,
+};
+
 RenderProcessHostPrivilege GetPrivilegeRequiredByUrl(
     const GURL& url,
     ExtensionRegistry* registry) {
@@ -196,6 +213,11 @@ void OnHttpHeaderReceived(const std::string& header,
   }
 }
 
+void RecordShowAllowOpenURLFailure(ShouldAllowOpenURLFailureReason reason) {
+  UMA_HISTOGRAM_ENUMERATION("Extensions.ShouldAllowOpenURL.Failure", reason,
+                            FAILURE_LAST);
+}
+
 }  // namespace
 
 ChromeContentBrowserClientExtensionsPart::
@@ -496,43 +518,82 @@ bool ChromeContentBrowserClientExtensionsPart::AllowServiceWorker(
 // static
 bool ChromeContentBrowserClientExtensionsPart::ShouldAllowOpenURL(
     content::SiteInstance* site_instance,
-    const GURL& from_url,
     const GURL& to_url,
     bool* result) {
   DCHECK(result);
 
+  // Using url::Origin is important to properly handle blob: and filesystem:
+  // URLs.
+  url::Origin to_origin(to_url);
+  if (to_origin.scheme() != kExtensionScheme) {
+    // We're not responsible for protecting this resource.  Note that hosted
+    // apps fall into this category.
+    return false;
+  }
+
   // Do not allow pages from the web or other extensions navigate to
   // non-web-accessible extension resources.
-  if (to_url.SchemeIs(kExtensionScheme) &&
-      (from_url.SchemeIsHTTPOrHTTPS() || from_url.SchemeIs(kExtensionScheme))) {
-    Profile* profile = Profile::FromBrowserContext(
-        site_instance->GetProcess()->GetBrowserContext());
-    ExtensionRegistry* registry = ExtensionRegistry::Get(profile);
-    if (!registry) {
-      *result = true;
-      return true;
-    }
-    const Extension* extension =
-        registry->enabled_extensions().GetExtensionOrAppByURL(to_url);
-    if (!extension) {
-      *result = true;
-      return true;
-    }
-    const Extension* from_extension =
-        registry->enabled_extensions().GetExtensionOrAppByURL(
-            site_instance->GetSiteURL());
-    if (from_extension && from_extension->id() == extension->id()) {
-      *result = true;
-      return true;
-    }
 
-    if (!WebAccessibleResourcesInfo::IsResourceWebAccessible(
-            extension, to_url.path())) {
-      *result = false;
-      return true;
-    }
+  ExtensionRegistry* registry =
+      ExtensionRegistry::Get(site_instance->GetBrowserContext());
+  const Extension* to_extension =
+      registry->enabled_extensions().GetByID(to_origin.host());
+  if (!to_extension) {
+    *result = true;
+    return true;
   }
-  return false;
+
+  GURL site_url(site_instance->GetSiteURL());
+  const Extension* from_extension =
+      registry->enabled_extensions().GetExtensionOrAppByURL(site_url);
+  if (from_extension && from_extension == to_extension) {
+    *result = true;
+    return true;
+  }
+
+  // Blob and filesystem URLs are never considered web-accessible.  See
+  // https://crbug.com/656752.
+  if (to_url.SchemeIsFileSystem() || to_url.SchemeIsBlob()) {
+    if (to_url.SchemeIsFileSystem())
+      RecordShowAllowOpenURLFailure(FAILURE_FILE_SYSTEM_URL);
+    else
+      RecordShowAllowOpenURLFailure(FAILURE_BLOB_URL);
+
+    *result = false;
+    return true;
+  }
+
+  // Navigations from chrome:// or chrome-search:// pages need to be allowed,
+  // even if |to_url| is not web-accessible.  See https://crbug.com/662602.
+  //
+  // Note that this is intentionally done after the check for blob: and
+  // filesystem: URLs above, for consistency with the renderer-side checks
+  // which already disallow navigations from chrome URLs to blob/filesystem
+  // URLs.
+  if (site_url.SchemeIs(content::kChromeUIScheme) ||
+      site_url.SchemeIs(chrome::kChromeSearchScheme)) {
+    *result = true;
+    return true;
+  }
+
+  if (WebAccessibleResourcesInfo::IsResourceWebAccessible(to_extension,
+                                                          to_url.path())) {
+    *result = true;
+    return true;
+  }
+
+  if (!site_url.SchemeIsHTTPOrHTTPS() && !site_url.SchemeIs(kExtensionScheme)) {
+    // Previous version of this function skipped the web-accessible
+    // resource checks in this case.  Collect data to see how often this
+    // happened.
+    RecordShowAllowOpenURLFailure(
+        FAILURE_SCHEME_NOT_HTTP_OR_HTTPS_OR_EXTENSION);
+  } else {
+    RecordShowAllowOpenURLFailure(FAILURE_RESOURCE_NOT_WEB_ACCESSIBLE);
+  }
+
+  *result = false;
+  return true;
 }
 
 // static