net: Restrict period when cs_vNodes mutex is locked

Author: hebasto

src/init.cpp

@@ -200,20 +200,7 @@ void Shutdown(NodeContext& node)
     // Because these depend on each-other, we make sure that neither can be
     // using the other before destroying them.
     if (node.peerman) UnregisterValidationInterface(node.peerman.get());
-    // Follow the lock order requirements:
-    // * CheckForStaleTipAndEvictPeers locks cs_main before indirectly calling GetExtraFullOutboundCount
-    //   which locks cs_vNodes.
-    // * ProcessMessage locks cs_main and g_cs_orphans before indirectly calling ForEachNode which
-    //   locks cs_vNodes.
-    // * CConnman::Stop calls DeleteNode, which calls FinalizeNode, which locks cs_main and calls
-    //   EraseOrphansFor, which locks g_cs_orphans.
-    //
-    // Thus the implicit locking order requirement is: (1) cs_main, (2) g_cs_orphans, (3) cs_vNodes.
-    if (node.connman) {
-        node.connman->StopThreads();
-        LOCK2(::cs_main, ::g_cs_orphans);
-        node.connman->StopNodes();
-    }
+    if (node.connman) node.connman->Stop();
 
     StopTorControl();
 

src/net.cpp

@@ -2636,22 +2636,22 @@ void CConnman::StopNodes()
     }
 
     // Close sockets
-    LOCK(cs_vNodes);
-    for (CNode* pnode : vNodes)
+    std::vector<CNode*> nodes;
+    WITH_LOCK(cs_vNodes, nodes.swap(vNodes));
+    for (CNode* pnode : nodes)
         pnode->CloseSocketDisconnect();
     for (ListenSocket& hListenSocket : vhListenSocket)
         if (hListenSocket.socket != INVALID_SOCKET)
             if (!CloseSocket(hListenSocket.socket))
                 LogPrintf("CloseSocket(hListenSocket) failed with error %s\n", NetworkErrorString(WSAGetLastError()));
 
     // clean up some globals (to help leak detection)
-    for (CNode* pnode : vNodes) {
+    for (CNode* pnode : nodes) {
         DeleteNode(pnode);
     }
     for (CNode* pnode : vNodesDisconnected) {
         DeleteNode(pnode);
     }
-    vNodes.clear();
     vNodesDisconnected.clear();
     vhListenSocket.clear();
     semOutbound.reset();

src/test/fuzz/process_message.cpp

@@ -100,7 +100,6 @@ void fuzz_target(FuzzBufferType buffer, const std::string& LIMIT_TO_MESSAGE_TYPE
         g_setup->m_node.peerman->SendMessages(&p2p_node);
     }
     SyncWithValidationInterfaceQueue();
-    LOCK2(::cs_main, g_cs_orphans); // See init.cpp for rationale for implicit locking order requirement
     g_setup->m_node.connman->StopNodes();
 }
 

src/test/fuzz/process_messages.cpp

@@ -80,6 +80,5 @@ FUZZ_TARGET_INIT(process_messages, initialize_process_messages)
         }
     }
     SyncWithValidationInterfaceQueue();
-    LOCK2(::cs_main, g_cs_orphans); // See init.cpp for rationale for implicit locking order requirement
     g_setup->m_node.connman->StopNodes();
 }