From 567f2357f9fda4eb40594f52342b85540b817287 Mon Sep 17 00:00:00 2001
From: Rubin Xu <rubinxu@google.com>
Date: Fri, 15 Mar 2019 11:38:36 +0000
Subject: [PATCH] DO NOT MERGE Make a copy of data stored in
 LockSettingsStorage cache

In general the cache should store copies of the original data
to prevent the caller from accidentally corrupting the cache after
the data is cached. This wasn't an issue until recently when
LockSettingsService starts to aggressively zeroize buffers,
which caused some unit test failures.

Bug: 120484642
Test: atest frameworks/base/services/tests/servicestests/src/com/android/server/locksettings/
Change-Id: I8cc61789f19613cca8ed36ca34aa42fe6b2ad674
(cherry picked from commit 4728d2114cae96127211637aea682ea89ceb7e24)
---
 .../server/locksettings/LockSettingsStorage.java     | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/services/core/java/com/android/server/locksettings/LockSettingsStorage.java b/services/core/java/com/android/server/locksettings/LockSettingsStorage.java
index 98f1740aa9860..2ede384f3edfa 100644
--- a/services/core/java/com/android/server/locksettings/LockSettingsStorage.java
+++ b/services/core/java/com/android/server/locksettings/LockSettingsStorage.java
@@ -29,7 +29,6 @@ import android.database.sqlite.SQLiteOpenHelper;
 import android.os.Environment;
 import android.os.UserHandle;
 import android.os.UserManager;
-import android.os.storage.StorageManager;
 import android.util.ArrayMap;
 import android.util.Log;
 import android.util.Slog;
@@ -49,6 +48,7 @@ import java.io.File;
 import java.io.IOException;
 import java.io.RandomAccessFile;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
 
@@ -808,7 +808,7 @@ class LockSettingsStorage {
         }
 
         byte[] peekFile(String fileName) {
-            return (byte[]) peek(CacheKey.TYPE_FILE, fileName, -1 /* userId */);
+            return copyOf((byte[]) peek(CacheKey.TYPE_FILE, fileName, -1 /* userId */));
         }
 
         boolean hasFile(String fileName) {
@@ -816,11 +816,11 @@ class LockSettingsStorage {
         }
 
         void putFile(String key, byte[] value) {
-            put(CacheKey.TYPE_FILE, key, value, -1 /* userId */);
+            put(CacheKey.TYPE_FILE, key, copyOf(value), -1 /* userId */);
         }
 
         void putFileIfUnchanged(String key, byte[] value, int version) {
-            putIfUnchanged(CacheKey.TYPE_FILE, key, value, -1 /* userId */, version);
+            putIfUnchanged(CacheKey.TYPE_FILE, key, copyOf(value), -1 /* userId */, version);
         }
 
         void setFetched(int userId) {
@@ -868,6 +868,10 @@ class LockSettingsStorage {
             mVersion++;
         }
 
+        private byte[] copyOf(byte[] data) {
+            return data != null ? Arrays.copyOf(data, data.length) : null;
+        }
+
         synchronized void purgePath(String path) {
             for (int i = mCache.size() - 1; i >= 0; i--) {
                 CacheKey entry = mCache.keyAt(i);