commit 2bd5cff7c639ed4bba2fc7ba3a545f4c764f0019
author Amith Yamasani <yamasani@google.com> Wed Jul 22 14:42:31 2015 -0700
committer Amith Yamasani <yamasani@google.com> Wed Jul 22 14:42:31 2015 -0700
tree e80bcc27bb273ffbe0a0e2d15a9fef88f551d17c
parent 1fcb6d3ae27ac95388eb036d124bd4bd0c6559cc

Avoid a deadlock between PMS and AppOpsService

Don't check for external storage access rights from MountService
for system server. Otherwise there's a case where AppOpsService
is locked and PackageManagerService calls into AppOps with its
own lock held and is unable to do an AppOps check via this path.

Bug: 22522725
Change-Id: Ib4cf914638905de391384aa5122e691c5a7140ec

services/core/java/com/android/server/MountService.java

diff --git a/services/core/java/com/android/server/MountService.java b/services/core/java/com/android/server/MountService.java
index 92b98a7..ed136e9 100644
--- a/services/core/java/com/android/server/MountService.java
+++ b/services/core/java/com/android/server/MountService.java
@@ -3431,6 +3431,11 @@
         }
 
         public boolean hasExternalStorage(int uid, String packageName) {
+            // No need to check for system uid. This avoids a deadlock between
+            // PackageManagerService and AppOpsService.
+            if (uid == Process.SYSTEM_UID) {
+                return true;
+            }
             // No locking - CopyOnWriteArrayList
             for (ExternalStorageMountPolicy policy : mPolicies) {
                 final boolean policyHasStorage = policy.hasExternalStorage(uid, packageName);