Added nullchecks to prevent page crash

Author: itskartike910

src/components/action_url/content/browser/content_action_url_driver.cc

@@ -29,6 +29,10 @@ class ActionUrlHandlerAndroid;
 namespace {
 
 bool IsRenderFrameHostSupported(content::RenderFrameHost* rfh) {
+  if (!rfh) {
+    return false;
+  }
+  
   if (rfh->GetLifecycleState() ==
       content::RenderFrameHost::LifecycleState::kPendingCommit) {
     return true;
@@ -46,13 +50,21 @@ bool IsRenderFrameHostSupported(content::RenderFrameHost* rfh) {
 ContentActionUrlDriver::ContentActionUrlDriver(
     content::RenderFrameHost* render_frame_host)
     : render_frame_host_(render_frame_host) {
+  if (!render_frame_host_) {
+    LOG(ERROR) << "AMIT ContentActionUrlDriver: render_frame_host is null!";
+    return;
+  }
   static unsigned next_free_id = 0;
   id_ = next_free_id++;
   handler_processing_remaining_ = 0;
   action_block_draw_remaining_ = 0;
   requested_for_header_ = false;
 
-  LOG(INFO) << "AMIT ContentActionUrlDriver constructor before get interface";
+  if (!render_frame_host_->GetRemoteAssociatedInterfaces()) {
+    LOG(ERROR) << "AMIT ContentActionUrlDriver: RemoteAssociatedInterfaces is null!";
+    return;
+  }
+  
   render_frame_host_->GetRemoteAssociatedInterfaces()->GetInterface(
       &action_url_agent_);
   LOG(INFO) << "AMIT action_url_agent_ is bound: " << action_url_agent_.is_bound();
@@ -64,12 +76,23 @@ ContentActionUrlDriver::~ContentActionUrlDriver() = default;
 void ContentActionUrlDriver::BindPendingReceiver(
     mojo::PendingAssociatedReceiver<action_url::mojom::ActionUrlDriver>
         pending_receiver) {
+  if (!render_frame_host_) {
+    LOG(ERROR) << "AMIT BindPendingReceiver: render_frame_host_ is null!";
+    return;
+  }
+  
   if (IsRenderFrameHostSupported(render_frame_host_)) {
     action_url_receiver_.Bind(std::move(pending_receiver));
   }
 }
 
 void ContentActionUrlDriver::DidNavigate() {
+  if (!render_frame_host_) {
+    LOG(ERROR) << "AMIT DidNavigate: render_frame_host_ is null!";
+    action_url_receiver_.reset();
+    return;
+  }
+  
   if (!IsRenderFrameHostSupported(render_frame_host_)) {
     action_url_receiver_.reset();
   }
@@ -83,6 +106,11 @@ int ContentActionUrlDriver::GetId() const {
 void ContentActionUrlDriver::AllAnchorsParsed(
     const std::vector<action_url::AnchorData>& anchors_data) {
 
+  if (!render_frame_host_) {
+    LOG(ERROR) << "AMIT AllAnchorsParsed: render_frame_host_ is null!";
+    return;
+  }
+
   Profile* profile = Profile::FromBrowserContext(render_frame_host_->GetBrowserContext());
   if (!profile->GetPrefs()->GetBoolean(action_url::prefs::kBlinksEnabled)) {
     LOG(INFO) << "AMIT Blinks are disabled";
@@ -165,6 +193,11 @@ void ContentActionUrlDriver::ActionUrlFetched(action_url::AnchorData anchor,
 void ContentActionUrlDriver::ProcessActionUrl(GURL action_url,
                                               action_url::AnchorData anchor,
                                               std::string tag) {
+  if (!render_frame_host_) {
+    LOG(ERROR) << "AMIT ProcessActionUrl: render_frame_host_ is null!";
+    return;
+  }
+
   std::unique_ptr<network::ResourceRequest> request =
       std::make_unique<network::ResourceRequest>();
   request->url = action_url;
@@ -228,6 +261,12 @@ void ContentActionUrlDriver::OnDownloadedJson(
 const mojo::AssociatedRemote<action_url::mojom::ActionUrlAgent>&
 ContentActionUrlDriver::GetActionUrlAgent() {
   LOG(INFO) << "AMIT GetActionUrlAgent";
+  
+  if (!render_frame_host_) {
+    LOG(ERROR) << "AMIT GetActionUrlAgent: render_frame_host_ is null!";
+    return action_url_agent_unbound_;
+  }
+  
   CHECK_NE(render_frame_host_->GetLifecycleState(),
            content::RenderFrameHost::LifecycleState::kPendingCommit);
   LOG(INFO) << "AMIT GetActionUrlAgent 2";

src/components/action_url/content/renderer/action_url_agent.cc

@@ -54,6 +54,13 @@ mojom::ActionUrlDriver& ActionUrlAgent::GetActionUrlDriver() {
   //   return *deferring_password_manager_driver_;
   // }
   LOG(INFO) << "AMIT GetActionUrlDriver";
+  if (!render_frame()) {
+    LOG(ERROR) << "AMIT GetActionUrlDriver: render_frame() is null!";
+    // Return a static unbound driver to prevent crash
+    static mojo::AssociatedRemote<mojom::ActionUrlDriver> unbound_driver_;
+    return *unbound_driver_;
+  }
+  
   // Lazily bind this interface.
   if (!action_url_driver_) {
     LOG(INFO) << "AMIT GetActionUrlDriver 1";
@@ -70,12 +77,23 @@ void ActionUrlAgent::Reset() {
   action_block_counter_ = 1;
   renderer_anchor_cache_.clear();
   buffer_for_anchors_.clear();
-  GetActionUrlDriver().Reset();
+  
+  if (render_frame()) {
+    GetActionUrlDriver().Reset();
+  } else {
+    LOG(ERROR) << "AMIT Reset: render_frame() is null!";
+  }
 }
 
 // mojom::ActionUrlAgent:
 void ActionUrlAgent::SetUpHeader() {
   LOG(INFO) << "Unfurling :: " << __func__;
+  
+  if (!render_frame()) {
+    LOG(ERROR) << "AMIT SetUpHeader: render_frame() is null!";
+    return;
+  }
+  
   render_frame()->GetWebFrame()->GetDocument().SetUpActionUrlHeader();
 }
 
@@ -107,6 +125,12 @@ void ActionUrlAgent::ReplaceUrL(const std::string& json,
 void ActionUrlAgent::SetUpScriptBlock() {
   LOG(INFO)<< "AMIT Setting up action url script block in action url agent";
   LOG(INFO) << "Unfurling :: " << __func__;
+  
+  if (!render_frame()) {
+    LOG(ERROR) << "AMIT SetUpScriptBlock: render_frame() is null!";
+    return;
+  }
+  
   render_frame()->GetWebFrame()->GetDocument().SetUpActionUrlScriptBlock();
 }
 
@@ -127,6 +151,12 @@ void ActionUrlAgent::DidCommitProvisionalLoad(ui::PageTransition transition) {
 
 void ActionUrlAgent::DidCreateDocumentElement() {
   Reset();
+  
+  if (!render_frame()) {
+    LOG(ERROR) << "AMIT DidCreateDocumentElement: render_frame() is null!";
+    return;
+  }
+  
   render_frame()->GetWebFrame()->GetDocument().ResetScriptState();
 }
 
@@ -135,6 +165,12 @@ void ActionUrlAgent::DidDispatchDOMContentLoadedEvent() {
   // Parse the content and find all anchor elements
   LOG(INFO) << "Unfurling :: " << __func__;
   is_dom_content_loaded_ = true;
+  
+  if (!render_frame()) {
+    LOG(ERROR) << "AMIT DidDispatchDOMContentLoadedEvent: render_frame() is null!";
+    return;
+  }
+  
   render_frame()->GetWebFrame()->GetDocument().ResetScriptState();
   FindAnchorElementsOnPage(false);
 }
@@ -158,10 +194,23 @@ void ActionUrlAgent::WaitTillDynamicChangeTimer(base::OneShotTimer& timer) {
 
 // Top-level wrapper call to trigger DOM traversal to find anchor element.
 void ActionUrlAgent::FindAnchorElementsOnPage(bool is_dynamic) {
+  if (!render_frame()) {
+    LOG(ERROR) << "AMIT FindAnchorElementsOnPage: render_frame() is null!";
+    return;
+  }
+  
   const blink::WebDocument doc = render_frame()->GetWebFrame()->GetDocument();
   if (doc.IsNull() || doc.Body().IsNull()) {
     return;
   }
+
+  // Enabling only for x.com pages
+  GURL page_url = GURL(doc.Url());
+  if (!page_url.is_valid() || page_url.host() != "x.com") {
+    LOG(INFO) << "AMIT Skipping non-x.com page";
+    return;
+  }
+
   WebVector<WebAnchorElement> anchor_elements;
   if (is_dynamic) {
     buffer_mu_.Acquire();
@@ -405,6 +454,12 @@ void ActionUrlAgent::OnJsonParsed(WebAnchorElement anchor,
 void ActionUrlAgent::ActionBlockDrawCompleted() {
   LOG(INFO) << "Unfurling :: " << __func__;
   LOG(INFO) << "AMIT Action block draw completed";
+  
+  if (!render_frame()) {
+    LOG(ERROR) << "AMIT ActionBlockDrawCompleted: render_frame() is null!";
+    return;
+  }
+  
   GetActionUrlDriver().OnBlockDrawCompleted();
 }