From 9ed97d606aaaf79776b0e19a73ba30d8ad0685b5 Mon Sep 17 00:00:00 2001
From: Ben Turner <bent.mozilla@gmail.com>
Date: Tue, 26 May 2015 17:27:01 -0400
Subject: [PATCH] Bug 1163109 - Restrict the resource:// weirdness in workers
 to loads from a system principal. r=bzbarsky, a=lizzard

--HG--
extra : transplant_source : sQUdu%7C%ED%84%CA%5B%91%89/%1B2%25%CFY%B0%C3
---
 dom/workers/ScriptLoader.cpp | 37 ++++++++++++++++---------------------
 1 file changed, 16 insertions(+), 21 deletions(-)

diff --git a/dom/workers/ScriptLoader.cpp b/dom/workers/ScriptLoader.cpp
index 0dfe625..3335c3e 100644
--- a/dom/workers/ScriptLoader.cpp
+++ b/dom/workers/ScriptLoader.cpp
@@ -509,22 +509,6 @@ private:
       rv = ssm->GetChannelPrincipal(channel, getter_AddRefs(channelPrincipal));
       NS_ENSURE_SUCCESS(rv, rv);
 
-      // See if this is a resource URI. Since JSMs usually come from resource://
-      // URIs we're currently considering all URIs with the URI_IS_UI_RESOURCE
-      // flag as valid for creating privileged workers.
-      if (!nsContentUtils::IsSystemPrincipal(channelPrincipal)) {
-        bool isResource;
-        rv = NS_URIChainHasFlags(finalURI,
-                                 nsIProtocolHandler::URI_IS_UI_RESOURCE,
-                                 &isResource);
-        NS_ENSURE_SUCCESS(rv, rv);
-
-        if (isResource) {
-          rv = ssm->GetSystemPrincipal(getter_AddRefs(channelPrincipal));
-          NS_ENSURE_SUCCESS(rv, rv);
-        }
-      }
-
       // If the load principal is the system principal then the channel
       // principal must also be the system principal (we do not allow chrome
       // code to create workers with non-chrome scripts). Otherwise this channel
@@ -532,14 +516,25 @@ private:
       // here in case redirects changed the location of the script).
       if (nsContentUtils::IsSystemPrincipal(loadPrincipal)) {
         if (!nsContentUtils::IsSystemPrincipal(channelPrincipal)) {
-          return NS_ERROR_DOM_BAD_URI;
+          // See if this is a resource URI. Since JSMs usually come from
+          // resource:// URIs we're currently considering all URIs with the
+          // URI_IS_UI_RESOURCE flag as valid for creating privileged workers.
+          bool isResource;
+          rv = NS_URIChainHasFlags(finalURI,
+                                   nsIProtocolHandler::URI_IS_UI_RESOURCE,
+                                   &isResource);
+          NS_ENSURE_SUCCESS(rv, rv);
+
+          if (isResource) {
+            // Assign the system principal to the resource:// worker only if it
+            // was loaded from code using the system principal.
+            channelPrincipal = loadPrincipal;
+          } else {
+            return NS_ERROR_DOM_BAD_URI;
+          }
         }
       }
       else  {
-        nsCString scheme;
-        rv = finalURI->GetScheme(scheme);
-        NS_ENSURE_SUCCESS(rv, rv);
-
         // We exempt data urls and other URI's that inherit their
         // principal again.
         if (NS_FAILED(loadPrincipal->CheckMayLoad(finalURI, false, true))) {
-- 
2.4.3