From 31c9cd197b2b1c352e0075239791ba7f0960ace8 Mon Sep 17 00:00:00 2001
From: Eugene Susla <eugenesusla@google.com>
Date: Mon, 3 Dec 2018 15:41:31 -0800
Subject: [PATCH] Intersect requestedPermissions with that of current update's
 one

Fixes: 120092266
Test: - install apk https://drive.google.com/file/d/1eh2mCz-0Ymm4TghOaf46ZHdn2-M8bm6i/view?usp=sharing
 - hardcode DefaultPermissionGrantPolicy to always run on reboot
 - adb reboot
 - ensure device bootloobs with an error from attached bug
 - apply fix
 - ensure device no longer bootloops
 - ensure no error in logcat
Change-Id: If2387e963b63231b0b99a55fdb7e75187d07bd07
---
 .../com/android/internal/util/ArrayUtils.java | 27 +++++++++++++++++++
 .../DefaultPermissionGrantPolicy.java         | 12 ++++++++-
 2 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/core/java/com/android/internal/util/ArrayUtils.java b/core/java/com/android/internal/util/ArrayUtils.java
index 4b662670f5e73..f669e94c17795 100644
--- a/core/java/com/android/internal/util/ArrayUtils.java
+++ b/core/java/com/android/internal/util/ArrayUtils.java
@@ -32,6 +32,7 @@ import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.function.IntFunction;
 
 /**
  * ArrayUtils contains some methods that you can call to find out
@@ -656,4 +657,30 @@ public class ArrayUtils {
             throw new ArrayIndexOutOfBoundsException("length=" + len + "; index=" + index);
         }
     }
+
+    /**
+     * Returns an array with values from {@code val} minus {@code null} values
+     *
+     * @param arrayConstructor typically {@code T[]::new} e.g. {@code String[]::new}
+     */
+    public static <T> T[] filterNotNull(T[] val, IntFunction<T[]> arrayConstructor) {
+        int nullCount = 0;
+        int size = size(val);
+        for (int i = 0; i < size; i++) {
+            if (val[i] == null) {
+                nullCount++;
+            }
+        }
+        if (nullCount == 0) {
+            return val;
+        }
+        T[] result = arrayConstructor.apply(size - nullCount);
+        int outIdx = 0;
+        for (int i = 0; i < size; i++) {
+            if (val[i] != null) {
+                result[outIdx++] = val[i];
+            }
+        }
+        return result;
+    }
 }
diff --git a/services/core/java/com/android/server/pm/permission/DefaultPermissionGrantPolicy.java b/services/core/java/com/android/server/pm/permission/DefaultPermissionGrantPolicy.java
index 68fe1d8a05f80..51619cf940a8b 100644
--- a/services/core/java/com/android/server/pm/permission/DefaultPermissionGrantPolicy.java
+++ b/services/core/java/com/android/server/pm/permission/DefaultPermissionGrantPolicy.java
@@ -46,7 +46,6 @@ import android.os.Environment;
 import android.os.Handler;
 import android.os.Looper;
 import android.os.Message;
-import android.os.SystemProperties;
 import android.os.UserHandle;
 import android.os.storage.StorageManager;
 import android.permission.PermissionManager;
@@ -1059,6 +1058,17 @@ public final class DefaultPermissionGrantPolicy {
             return;
         }
 
+        // Intersect the requestedPermissions for a factory image with that of its current update
+        // in case the latter one removed a <uses-permission>
+        String[] requestedByNonSystemPackage = getPackageInfo(pkg.packageName).requestedPermissions;
+        int size = requestedPermissions.length;
+        for (int i = 0; i < size; i++) {
+            if (!ArrayUtils.contains(requestedByNonSystemPackage, requestedPermissions[i])) {
+                requestedPermissions[i] = null;
+            }
+        }
+        requestedPermissions = ArrayUtils.filterNotNull(requestedPermissions, String[]::new);
+
         PackageManager pm = mContext.getPackageManager();
         final ArraySet<String> permissions = new ArraySet<>(permissionsWithoutSplits);
         ApplicationInfo applicationInfo = pkg.applicationInfo;