Default grants: handle update system packages

If there is an app on the system image that gets default
grants but it is updated with a version that does not use
all permissions the version on the system image does, we
would wrongly try to grant a permission to the updated app
that it does not request and crash as a result. Now we
default grant permission that are requested by the system
version of the app regardless if it is updated but only if
the system app is not updated or the update also uses these
permissions.

bug:22800767

Change-Id: Ic22b62ba4976367420a56bdadc8e3824b0b9104f
diff --git a/services/core/java/com/android/server/pm/DefaultPermissionGrantPolicy.java b/services/core/java/com/android/server/pm/DefaultPermissionGrantPolicy.java
index 0d1d1ea..0cab1ec 100644
--- a/services/core/java/com/android/server/pm/DefaultPermissionGrantPolicy.java
+++ b/services/core/java/com/android/server/pm/DefaultPermissionGrantPolicy.java
@@ -165,30 +165,23 @@
 
         synchronized (mService.mPackages) {
             for (PackageParser.Package pkg : mService.mPackages.values()) {
-                if (!isSysComponentOrPersistentPlatformSignedPrivApp(pkg)
-                        || !doesPackageSupportRuntimePermissions(pkg)) {
+                if (!isSysComponentOrPersistentPlatformSignedPrivAppLPr(pkg)
+                        || !doesPackageSupportRuntimePermissions(pkg)
+                        || pkg.requestedPermissions.isEmpty()) {
                     continue;
                 }
+                Set<String> permissions = new ArraySet<>();
                 final int permissionCount = pkg.requestedPermissions.size();
                 for (int i = 0; i < permissionCount; i++) {
                     String permission = pkg.requestedPermissions.get(i);
                     BasePermission bp = mService.mSettings.mPermissions.get(permission);
                     if (bp != null && bp.isRuntime()) {
-                        final int flags = mService.getPermissionFlags(permission,
-                                pkg.packageName, userId);
-                        if ((flags & PackageManager.FLAG_PERMISSION_SYSTEM_FIXED) == 0) {
-                            mService.grantRuntimePermission(pkg.packageName, permission, userId);
-                            mService.updatePermissionFlags(permission, pkg.packageName,
-                                    PackageManager.MASK_PERMISSION_FLAGS,
-                                    PackageManager.FLAG_PERMISSION_SYSTEM_FIXED
-                                    | PackageManager.FLAG_PERMISSION_GRANTED_BY_DEFAULT, userId);
-                            if (DEBUG) {
-                                Log.i(TAG, "Granted " + permission + " to system component "
-                                        + pkg.packageName);
-                            }
-                        }
+                        permissions.add(permission);
                     }
                 }
+                if (!permissions.isEmpty()) {
+                    grantRuntimePermissionsLPw(pkg, permissions, true, userId);
+                }
             }
         }
     }
@@ -699,7 +692,7 @@
     private PackageParser.Package getSystemPackageLPr(String packageName) {
         PackageParser.Package pkg = getPackageLPr(packageName);
         if (pkg != null && pkg.isSystemApp()) {
-            return !isSysComponentOrPersistentPlatformSignedPrivApp(pkg) ? pkg : null;
+            return !isSysComponentOrPersistentPlatformSignedPrivAppLPr(pkg) ? pkg : null;
         }
         return null;
     }
@@ -716,18 +709,36 @@
 
     private void grantRuntimePermissionsLPw(PackageParser.Package pkg, Set<String> permissions,
             boolean systemFixed, boolean overrideUserChoice,  int userId) {
+        if (pkg.requestedPermissions.isEmpty()) {
+            return;
+        }
+
         List<String> requestedPermissions = pkg.requestedPermissions;
+        Set<String> grantablePermissions = null;
 
         if (pkg.isUpdatedSystemApp()) {
             PackageSetting sysPs = mService.mSettings.getDisabledSystemPkgLPr(pkg.packageName);
             if (sysPs != null) {
-                requestedPermissions = sysPs.pkg.requestedPermissions;
+                if (sysPs.pkg.requestedPermissions.isEmpty()) {
+                    return;
+                }
+                if (!requestedPermissions.equals(sysPs.pkg.requestedPermissions)) {
+                    grantablePermissions = new ArraySet<>(requestedPermissions);
+                    requestedPermissions = sysPs.pkg.requestedPermissions;
+                }
             }
         }
 
-        final int permissionCount = requestedPermissions.size();
-        for (int i = 0; i < permissionCount; i++) {
+        final int grantablePermissionCount = requestedPermissions.size();
+        for (int i = 0; i < grantablePermissionCount; i++) {
             String permission = requestedPermissions.get(i);
+
+            // If there is a disabled system app it may request a permission the updated
+            // version ot the data partition doesn't, In this case skip the permission.
+            if (grantablePermissions != null && !grantablePermissions.contains(permission)) {
+                continue;
+            }
+
             if (permissions.contains(permission)) {
                 final int flags = mService.getPermissionFlags(permission, pkg.packageName, userId);
 
@@ -763,12 +774,19 @@
         }
     }
 
-    private boolean isSysComponentOrPersistentPlatformSignedPrivApp(PackageParser.Package pkg) {
+    private boolean isSysComponentOrPersistentPlatformSignedPrivAppLPr(PackageParser.Package pkg) {
         if (UserHandle.getAppId(pkg.applicationInfo.uid) < FIRST_APPLICATION_UID) {
             return true;
         }
-        if ((pkg.applicationInfo.privateFlags & ApplicationInfo.PRIVATE_FLAG_PRIVILEGED) == 0
-                || (pkg.applicationInfo.flags & ApplicationInfo.FLAG_PERSISTENT) == 0) {
+        if (!pkg.isPrivilegedApp()) {
+            return false;
+        }
+        PackageSetting sysPkg = mService.mSettings.getDisabledSystemPkgLPr(pkg.packageName);
+        if (sysPkg != null) {
+            if ((sysPkg.pkg.applicationInfo.flags & ApplicationInfo.FLAG_PERSISTENT) == 0) {
+                return false;
+            }
+        } else if ((pkg.applicationInfo.flags & ApplicationInfo.FLAG_PERSISTENT) == 0) {
             return false;
         }
         return PackageManagerService.compareSignatures(mService.mPlatformPackage.mSignatures,