When running walletpassphrase on a large wallet.dat (ie about 300,000 segwit P2SH addresses) the command sometimes takes a very long time, and if command is run multiple times at once (while running slow) it causes bitcoin core to freeze (stops syncing and requires kill -9 to stop/restart)

During the locked up walletpassphrase commands being run the following messages start to appear in the debug.log:

`018-01-24 01:01:04 socket sending timeout: 1201s`

Note that this problem is intermittent, so sometimes the command runs instantly, other times it takes a few minutes, and other times it completely freezes the node.
{
                strErr = "Error reading wallet database: CPubKey corrupt";
                return false;
            }
            CKey key;
            CPrivKey pkey;
            uint256 hash;
            wss.nKeys++;
            ssValue >> pkey;
            ssValue >> hash;
            
            std::vector<unsigned char> to_hash;
            to_hash.reserve(pubkey.size() + pkey.size());
            to_hash.insert(to_hash.end(), pubkey.begin(), pubkey.end());
            to_hash.insert(to_hash.end(), pkey.begin(), pkey.end());
            if (Hash(to_hash.begin(), to_hash.end()) != hash)
            {
                strErr = "Error reading wallet database: CPubKey/CPrivKey corrupt";
                return false;
            }
            if (!key.Load(pkey, pubkey, true))
            {
                strErr = "Error reading wallet database: CPrivKey corrupt";
                return false;
            }
            wss.m_descriptor_keys.insert(std::make_pair(std::make_pair(desc_id, pubkey.GetID()), key));
        } else if (strType == DBKeys::WALLETDESCRIPTORCKEY) {
            uint256 desc_id;
            CPubKey pubkey;
            ssKey >> desc_id;