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Fix deadlock in getOneTimePermissionUserManager().

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The OneTimePermissionUserManager constructor may acquire the package
manager lock inside, so we cannot call it while holding our permission
lock.

Fixes: 173097873
Test: presubmit
Change-Id: I7178bc0a642d6c42dfc9edf855dce72deaa1e699
This commit is contained in:
Hai Zhang
2020-11-16 10:10:29 -08:00
parent a5a96475fb
commit cd9f253cc4
1 changed files with 16 additions and 4 deletions
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20
services/core/java/com/android/server/pm/permission/PermissionManagerService.java
View File

@@ -3369,16 +3369,28 @@ public class PermissionManagerService extends IPermissionManager.Stub {
SystemConfig.getInstance().getSplitPermissions());
}
@NonNull
private OneTimePermissionUserManager getOneTimePermissionUserManager(@UserIdInt int userId) {
OneTimePermissionUserManager oneTimePermissionUserManager;
synchronized (mLock) {
oneTimePermissionUserManager =
mOneTimePermissionUserManagers.get(userId);
oneTimePermissionUserManager = mOneTimePermissionUserManagers.get(userId);
if (oneTimePermissionUserManager != null) {
return oneTimePermissionUserManager;
}
oneTimePermissionUserManager = new OneTimePermissionUserManager(
mContext.createContextAsUser(UserHandle.of(userId), /*flags*/ 0));
}
// We cannot create a new instance of OneTimePermissionUserManager while holding our own
// lock, which may lead to a deadlock with the package manager lock. So we do it in a
// retry-like way, and just discard the newly created instance if someone else managed to be
// a little bit faster than us when we dropped our own lock.
final OneTimePermissionUserManager newOneTimePermissionUserManager =
new OneTimePermissionUserManager(mContext.createContextAsUser(UserHandle.of(userId),
/*flags*/ 0));
synchronized (mLock) {
oneTimePermissionUserManager = mOneTimePermissionUserManagers.get(userId);
if (oneTimePermissionUserManager != null) {
return oneTimePermissionUserManager;
}
oneTimePermissionUserManager = newOneTimePermissionUserManager;
mOneTimePermissionUserManagers.put(userId, oneTimePermissionUserManager);
}
oneTimePermissionUserManager.registerUninstallListener();