Repository: electron/electron
Pull request: fix: re-entrancy issues in `webContents.loadURL()`

Backport of #48004

See that PR for details.


Notes: Fixed a crash possible when calling `webContents.loadURL()` from a failed `webContents.loadURL()` call's catch handler.

Changed files:
filename: shell/browser/api/electron_api_web_contents.cc
patch: @@ -2002,16 +2002,21 @@ SkRegion* WebContents::draggable_region() {
 
 void WebContents::DidStartNavigation(
     content::NavigationHandle* navigation_handle) {
+  base::AutoReset<bool> resetter(&is_safe_to_delete_, false);
   EmitNavigationEvent("did-start-navigation", navigation_handle);
 }
 
 void WebContents::DidRedirectNavigation(
     content::NavigationHandle* navigation_handle) {
+  base::AutoReset<bool> resetter(&is_safe_to_delete_, false);
   EmitNavigationEvent("did-redirect-navigation", navigation_handle);
 }
 
 void WebContents::ReadyToCommitNavigation(
     content::NavigationHandle* navigation_handle) {
+  base::AutoReset<bool> resetter(&is_safe_to_delete_, false);
+  EmitNavigationEvent("-ready-to-commit-navigation", navigation_handle);
+
   // Don't focus content in an inactive window.
   if (!owner_window())
     return;
@@ -2354,7 +2359,7 @@ void WebContents::LoadURL(const GURL& url,
   // http://crbug.com/347742.
   auto& ctrl_impl = static_cast<content::NavigationControllerImpl&>(
       web_contents()->GetController());
-  if (ctrl_impl.in_navigate_to_pending_entry()) {
+  if (!is_safe_to_delete_ || ctrl_impl.in_navigate_to_pending_entry()) {
     Emit("did-fail-load", static_cast<int>(net::ERR_FAILED),
          net::ErrorToShortString(net::ERR_FAILED), url.possibly_invalid_spec(),
          true);

filename: shell/browser/api/electron_api_web_contents.h
patch: @@ -856,6 +856,9 @@ class WebContents final : public ExclusiveAccessContext,
   const scoped_refptr<base::TaskRunner> print_task_runner_;
 #endif
 
+  // Track navigation state in order to avoid potential re-entrancy crashes.
+  bool is_safe_to_delete_ = true;
+
   // Stores the frame that's currently in fullscreen, nullptr if there is none.
   raw_ptr<content::RenderFrameHost> fullscreen_frame_ = nullptr;
 

filename: spec/api-web-contents-spec.ts
patch: @@ -484,7 +484,7 @@ describe('webContents module', () => {
       }
     });
 
-    it('fails if loadURL is called inside a non-reentrant critical section', (done) => {
+    it('fails if loadURL is called inside did-start-loading', (done) => {
       w.webContents.once('did-fail-load', (_event, _errorCode, _errorDescription, validatedURL) => {
         expect(validatedURL).to.contain('blank.html');
         done();
@@ -497,6 +497,49 @@ describe('webContents module', () => {
       w.loadURL('data:text/html,<h1>HELLO</h1>');
     });
 
+    it('fails if loadurl is called after the navigation is ready to commit', () => {
+      w.webContents.once('did-fail-load', (_event, _errorCode, _errorDescription, validatedURL) => {
+        expect(validatedURL).to.contain('blank.html');
+      });
+
+      // @ts-expect-error internal-only event.
+      w.webContents.once('-ready-to-commit-navigation', () => {
+        w.loadURL(`file://${fixturesPath}/pages/blank.html`);
+      });
+
+      w.loadURL('data:text/html,<h1>HELLO</h1>');
+    });
+
+    it('fails if loadURL is called inside did-redirect-navigation', (done) => {
+      const server = http.createServer((req, res) => {
+        if (req.url === '/302') {
+          res.statusCode = 302;
+          res.setHeader('Location', '/200');
+          res.end();
+        } else if (req.url === '/200') {
+          res.end('ok');
+        } else {
+          res.end();
+        }
+      });
+
+      w.webContents.once('did-fail-load', (_event, _errorCode, _errorDescription, validatedURL) => {
+        expect(validatedURL).to.contain('blank.html');
+        server.close();
+        done();
+      });
+
+      listen(server).then(({ url }) => {
+        w.webContents.once('did-redirect-navigation', () => {
+          w.loadURL(`file://${fixturesPath}/pages/blank.html`);
+        });
+        w.loadURL(`${url}/302`);
+      }).catch(e => {
+        server.close();
+        done(e);
+      });
+    });
+
     it('sets appropriate error information on rejection', async () => {
       let err: any;
       try {