Fix a NPE in AccessiiblityManagerService.

It is possible that the accessibility windows list is null which
is treated as if there is no window information. The getWindows
method was accessing properties of the windows filed witgout a
null check.

bug:18522998

Change-Id: Ieefe678d3da3d6e8f96c0e4bedac0c55975621fa

1 files changed, 3 insertions, 0 deletions

diff --git a/services/accessibility/java/com/android/server/accessibility/AccessibilityManagerService.java b/services/accessibility/java/com/android/server/accessibility/AccessibilityManagerService.java
index 89aebe8..698d474 100644
--- a/services/accessibility/java/com/android/server/accessibility/AccessibilityManagerService.java
+++ b/services/accessibility/java/com/android/server/accessibility/AccessibilityManagerService.java
@@ -2145,6 +2145,9 @@ public class AccessibilityManagerService extends IAccessibilityManager.Stub {
                 if (!permissionGranted) {
                     return null;
                 }
+                if (mSecurityPolicy.mWindows == null) {
+                    return null;
+                }
                 List<AccessibilityWindowInfo> windows = new ArrayList<>();
                 final int windowCount = mSecurityPolicy.mWindows.size();
                 for (int i = 0; i < windowCount; i++) {