From bb108a18393edde0e767d882dceef70a9fb1839e Mon Sep 17 00:00:00 2001
From: Jon Spivack <spivack@google.com>
Date: Fri, 13 Mar 2020 20:45:18 -0700
Subject: ServiceManager: Check guaranteeClient before unregistering services

If tryUnregisterService is called while a service has set guaranteeClient to true, it should not succeed. The flag means that a client exists and is about to be counted. Not checking this flag can lead to a race.

Bug: 151485917
Test: aidl_lazy_test
Change-Id: If7ef7a5c7521ea40521bd351385fb8bd650aba08
---
 cmds/servicemanager/ServiceManager.cpp | 5 +++++
 1 file changed, 5 insertions(+)

(limited to 'cmds/servicemanager/ServiceManager.cpp')

diff --git a/cmds/servicemanager/ServiceManager.cpp b/cmds/servicemanager/ServiceManager.cpp
index abe64365f3..0154620efb 100644
--- a/cmds/servicemanager/ServiceManager.cpp
+++ b/cmds/servicemanager/ServiceManager.cpp
@@ -522,6 +522,11 @@ Status ServiceManager::tryUnregisterService(const std::string& name, const sp<IB
         return Status::fromExceptionCode(Status::EX_ILLEGAL_STATE);
     }
 
+    if (serviceIt->second.guaranteeClient) {
+        LOG(INFO) << "Tried to unregister " << name << ", but there is about to be a client.";
+        return Status::fromExceptionCode(Status::EX_ILLEGAL_STATE);
+    }
+
     int clients = handleServiceClientCallback(name, false);
 
     // clients < 0: feature not implemented or other error. Assume clients.
-- 
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