rpc: Fix rpcRunLater race in walletpassphrase

This commit is contained in:
João Barbosa 2020-04-01 00:22:14 +01:00
parent d2db25233c
commit 7b8e15728d

View file

@ -1918,44 +1918,52 @@ static UniValue walletpassphrase(const JSONRPCRequest& request)
},
}.Check(request);
auto locked_chain = pwallet->chain().lock();
LOCK(pwallet->cs_wallet);
int64_t nSleepTime;
{
auto locked_chain = pwallet->chain().lock();
LOCK(pwallet->cs_wallet);
if (!pwallet->IsCrypted()) {
throw JSONRPCError(RPC_WALLET_WRONG_ENC_STATE, "Error: running with an unencrypted wallet, but walletpassphrase was called.");
if (!pwallet->IsCrypted()) {
throw JSONRPCError(RPC_WALLET_WRONG_ENC_STATE, "Error: running with an unencrypted wallet, but walletpassphrase was called.");
}
// Note that the walletpassphrase is stored in request.params[0] which is not mlock()ed
SecureString strWalletPass;
strWalletPass.reserve(100);
// TODO: get rid of this .c_str() by implementing SecureString::operator=(std::string)
// Alternately, find a way to make request.params[0] mlock()'d to begin with.
strWalletPass = request.params[0].get_str().c_str();
// Get the timeout
nSleepTime = request.params[1].get_int64();
// Timeout cannot be negative, otherwise it will relock immediately
if (nSleepTime < 0) {
throw JSONRPCError(RPC_INVALID_PARAMETER, "Timeout cannot be negative.");
}
// Clamp timeout
constexpr int64_t MAX_SLEEP_TIME = 100000000; // larger values trigger a macos/libevent bug?
if (nSleepTime > MAX_SLEEP_TIME) {
nSleepTime = MAX_SLEEP_TIME;
}
if (strWalletPass.empty()) {
throw JSONRPCError(RPC_INVALID_PARAMETER, "passphrase can not be empty");
}
if (!pwallet->Unlock(strWalletPass)) {
throw JSONRPCError(RPC_WALLET_PASSPHRASE_INCORRECT, "Error: The wallet passphrase entered was incorrect.");
}
pwallet->TopUpKeyPool();
pwallet->nRelockTime = GetTime() + nSleepTime;
}
// Note that the walletpassphrase is stored in request.params[0] which is not mlock()ed
SecureString strWalletPass;
strWalletPass.reserve(100);
// TODO: get rid of this .c_str() by implementing SecureString::operator=(std::string)
// Alternately, find a way to make request.params[0] mlock()'d to begin with.
strWalletPass = request.params[0].get_str().c_str();
// Get the timeout
int64_t nSleepTime = request.params[1].get_int64();
// Timeout cannot be negative, otherwise it will relock immediately
if (nSleepTime < 0) {
throw JSONRPCError(RPC_INVALID_PARAMETER, "Timeout cannot be negative.");
}
// Clamp timeout
constexpr int64_t MAX_SLEEP_TIME = 100000000; // larger values trigger a macos/libevent bug?
if (nSleepTime > MAX_SLEEP_TIME) {
nSleepTime = MAX_SLEEP_TIME;
}
if (strWalletPass.empty()) {
throw JSONRPCError(RPC_INVALID_PARAMETER, "passphrase can not be empty");
}
if (!pwallet->Unlock(strWalletPass)) {
throw JSONRPCError(RPC_WALLET_PASSPHRASE_INCORRECT, "Error: The wallet passphrase entered was incorrect.");
}
pwallet->TopUpKeyPool();
pwallet->nRelockTime = GetTime() + nSleepTime;
// rpcRunLater must be called without cs_wallet held otherwise a deadlock
// can occur. The deadlock would happen when RPCRunLater removes the
// previous timer (and waits for the callback to finish if already running)
// and the callback locks cs_wallet.
AssertLockNotHeld(wallet->cs_wallet);
// Keep a weak pointer to the wallet so that it is possible to unload the
// wallet before the following callback is called. If a valid shared pointer
// is acquired in the callback then the wallet is still loaded.