1 files changed, 50 insertions, 0 deletions
diff --git a/services/core/java/com/android/server/am/ActivityManagerService.java b/services/core/java/com/android/server/am/ActivityManagerService.java
index 23f34e6..3715620 100755
--- a/services/core/java/com/android/server/am/ActivityManagerService.java
+++ b/services/core/java/com/android/server/am/ActivityManagerService.java
@@ -219,6 +219,7 @@ import android.os.UpdateLock;
 import android.os.UserHandle;
 import android.os.UserManager;
 import android.provider.Settings;
+import android.provider.Downloads;
 import android.telecom.TelecomManager;
 import android.text.format.DateUtils;
 import android.text.format.Time;
@@ -8181,6 +8182,12 @@ public final class ActivityManagerService extends ActivityManagerNative
                     // Only inspect grants matching package
                     if (packageName == null || perm.sourcePkg.equals(packageName)
                             || perm.targetPkg.equals(packageName)) {
+                        // Hacky solution as part of fixing a security bug; ignore
+                        // grants associated with DownloadManager so we don't have
+                        // to immediately launch it to regrant the permissions
+                        if (Downloads.Impl.AUTHORITY.equals(perm.uri.uri.getAuthority())
+                                && !persistable) continue;
+
                         persistChanged |= perm.revokeModes(persistable
                                 ? ~0 : ~Intent.FLAG_GRANT_PERSISTABLE_URI_PERMISSION, true);
 
@@ -9623,6 +9630,44 @@ public final class ActivityManagerService extends ActivityManagerNative
     }
 
     /**
+     * Check if the calling UID has a possible chance at accessing the provider
+     * at the given authority and user.
+     */
+    public String checkContentProviderAccess(String authority, int userId) {
+        if (userId == UserHandle.USER_ALL) {
+            mContext.enforceCallingOrSelfPermission(
+                    Manifest.permission.INTERACT_ACROSS_USERS_FULL, TAG);
+            userId = UserHandle.getCallingUserId();
+        }
+
+        ProviderInfo cpi = null;
+        try {
+            cpi = AppGlobals.getPackageManager().resolveContentProvider(authority,
+                    STOCK_PM_FLAGS | PackageManager.GET_URI_PERMISSION_PATTERNS,
+                    userId);
+        } catch (RemoteException ignored) {
+        }
+        if (cpi == null) {
+            // TODO: make this an outright failure in a future platform release;
+            // until then anonymous content notifications are unprotected
+            //return "Failed to find provider " + authority + " for user " + userId;
+            return null;
+        }
+
+        ProcessRecord r = null;
+        synchronized (mPidsSelfLocked) {
+            r = mPidsSelfLocked.get(Binder.getCallingPid());
+        }
+        if (r == null) {
+            return "Failed to find PID " + Binder.getCallingPid();
+        }
+
+        synchronized (this) {
+            return checkContentProviderPermissionLocked(cpi, r, userId, true);
+        }
+    }
+
+    /**
      * Check if {@link ProcessRecord} has a possible chance at accessing the
      * given {@link ProviderInfo}. Final permission checking is always done
      * in {@link ContentProvider}.
@@ -21136,6 +21181,11 @@ public final class ActivityManagerService extends ActivityManagerNative
 
     private final class LocalService extends ActivityManagerInternal {
         @Override
+        public String checkContentProviderAccess(String authority, int userId) {
+            return ActivityManagerService.this.checkContentProviderAccess(authority, userId);
+        }
+
+        @Override
         public void onWakefulnessChanged(int wakefulness) {
             ActivityManagerService.this.onWakefulnessChanged(wakefulness);
         }