Bug 1557887 - Part 10: Prevent initial about:blank documents from escaping out of partitioned storage by using the correct storage principal when creating them; r=baku

Differential Revision: https://phabricator.services.mozilla.com/D34464

--HG--
extra : moz-landing-system : lando

docshell/base/nsDocShell.cpp

@@ -7146,14 +7146,17 @@ nsresult nsDocShell::CreateAboutBlankContentViewer(
       } else {
         principal = NullPrincipal::CreateWithInheritedAttributes(this);
       }
+      storagePrincipal = principal;
     } else {
       principal = aPrincipal;
+      storagePrincipal = aStoragePrincipal;
     }
 
     MaybeCreateInitialClientSource(principal);
 
     // generate (about:blank) document to load
-    blankDoc = nsContentDLF::CreateBlankDocument(mLoadGroup, principal, this);
+    blankDoc = nsContentDLF::CreateBlankDocument(mLoadGroup, principal,
+                                                 storagePrincipal, this);
     if (blankDoc) {
       // Hack: manually set the CSP for the new document
       // Please create an actual copy of the CSP (do not share the same

layout/build/nsContentDLF.cpp

@@ -262,7 +262,7 @@ nsContentDLF::CreateInstanceForDocument(nsISupports* aContainer,
 /* static */
 already_AddRefed<Document> nsContentDLF::CreateBlankDocument(
     nsILoadGroup* aLoadGroup, nsIPrincipal* aPrincipal,
-    nsDocShell* aContainer) {
+    nsIPrincipal* aStoragePrincipal, nsDocShell* aContainer) {
   // create a new blank HTML document
   RefPtr<Document> blankDoc;
   mozilla::Unused << NS_NewHTMLDocument(getter_AddRefs(blankDoc));
@@ -277,7 +277,7 @@ already_AddRefed<Document> nsContentDLF::CreateBlankDocument(
   if (!uri) {
     return nullptr;
   }
-  blankDoc->ResetToURI(uri, aLoadGroup, aPrincipal, aPrincipal);
+  blankDoc->ResetToURI(uri, aLoadGroup, aPrincipal, aStoragePrincipal);
   blankDoc->SetContainer(aContainer);
 
   // add some simple content structure

layout/build/nsContentDLF.h

@@ -52,7 +52,7 @@ class nsContentDLF final : public nsIDocumentLoaderFactory {
    */
   static already_AddRefed<mozilla::dom::Document> CreateBlankDocument(
       nsILoadGroup* aLoadGroup, nsIPrincipal* aPrincipal,
-      nsDocShell* aContainer);
+      nsIPrincipal* aStoragePrincipal, nsDocShell* aContainer);
 
  private:
   static nsresult EnsureUAStyleSheet();