Check underlying intent as well as intent selector

When checking if an intent can be forwarded across profiles, the
selector action is checked rather than the intent itself.
This means badIntents can be spoofed with a different selector and
launched across profiles.

Bug: 376674080
Test: manually tested
Flag: EXEMPT bugfix
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:85ef51a7a91de0e51dd65ce5f09badcd96835817)
Merged-In: I744d0d7f89e35665405a14a814d4e0861082a106
Change-Id: I744d0d7f89e35665405a14a814d4e0861082a106

1 files changed, 25 insertions, 10 deletions

diff --git a/java/src/com/android/intentresolver/IntentForwarderActivity.java b/java/src/com/android/intentresolver/IntentForwarderActivity.java
index 5e8945f1..edb85ec9 100644
--- a/java/src/com/android/intentresolver/IntentForwarderActivity.java
+++ b/java/src/com/android/intentresolver/IntentForwarderActivity.java
@@ -309,31 +309,46 @@ public class IntentForwarderActivity extends Activity  {
      * Check whether the intent can be forwarded to target user. Return the intent used for
      * forwarding if it can be forwarded, {@code null} otherwise.
      */
-    static Intent canForward(Intent incomingIntent, int sourceUserId, int targetUserId,
-            IPackageManager packageManager, ContentResolver contentResolver)  {
+
+    public static Intent canForward(Intent incomingIntent, int sourceUserId, int targetUserId,
+            IPackageManager packageManager, ContentResolver contentResolver) {
         Intent forwardIntent = new Intent(incomingIntent);
         forwardIntent.addFlags(
                 Intent.FLAG_ACTIVITY_FORWARD_RESULT | Intent.FLAG_ACTIVITY_PREVIOUS_IS_TOP);
         sanitizeIntent(forwardIntent);
 
-        Intent intentToCheck = forwardIntent;
-        if (Intent.ACTION_CHOOSER.equals(forwardIntent.getAction())) {
+        if (!canForwardInner(forwardIntent, sourceUserId, targetUserId, packageManager,
+                contentResolver)) {
             return null;
         }
+
         if (forwardIntent.getSelector() != null) {
-            intentToCheck = forwardIntent.getSelector();
+            sanitizeIntent(forwardIntent.getSelector());
+
+            if (!canForwardInner(forwardIntent.getSelector(), sourceUserId, targetUserId,
+                    packageManager, contentResolver)) {
+                return null;
+            }
         }
-        String resolvedType = intentToCheck.resolveTypeIfNeeded(contentResolver);
-        sanitizeIntent(intentToCheck);
+        return forwardIntent;
+    }
+
+    private static boolean canForwardInner(Intent intent, int sourceUserId, int targetUserId,
+            IPackageManager packageManager, ContentResolver contentResolver) {
+        if (Intent.ACTION_CHOOSER.equals(intent.getAction())) {
+            return false;
+        }
+
+        String resolvedType = intent.resolveTypeIfNeeded(contentResolver);
         try {
             if (packageManager.canForwardTo(
-                    intentToCheck, resolvedType, sourceUserId, targetUserId)) {
-                return forwardIntent;
+                    intent, resolvedType, sourceUserId, targetUserId)) {
+                return true;
             }
         } catch (RemoteException e) {
             Slog.e(TAG, "PackageManagerService is dead?");
         }
-        return null;
+        return false;
     }
 
     /**