Merge #18814: rpc: Relock wallet only if most recent callback

9f59dde974 rpc: Relock wallet only if most recent callback (João Barbosa)
a2e6db5c4f rpc: Add mutex to guard deadlineTimers (João Barbosa)

Pull request description:

  This PR fixes an early relocking race condition from #18811 where old relock callback runs after new wallet unlock code and nRelockTime update but before rpcRunLater call, causing early relock and incorrect nRelockTime time

  Issue introduced in #18487.
  Fixes #18811.

ACKs for top commit:
  MarcoFalke:
    ACK 9f59dde974
  ryanofsky:
    Code review ACK 9f59dde974. No changes since last review except squashing commits.
  jonatack:
    ACK 9f59dde974

Tree-SHA512: 2f7fc03e5ab6037337f2d82dfad432495cc337c77d07c968ee2355105db6292f24543c03456f5402e0e759577a4327758f9372f7ea29de6d56dc3695fda9b379
This commit is contained in:
fanquake
2020-05-13 17:29:10 +08:00
3 changed files with 14 additions and 4 deletions

View File

@@ -1892,6 +1892,9 @@ static UniValue walletpassphrase(const JSONRPCRequest& request)
}.Check(request);
int64_t nSleepTime;
int64_t relock_time;
// Prevent concurrent calls to walletpassphrase with the same wallet.
LOCK(pwallet->m_unlock_mutex);
{
LOCK(pwallet->cs_wallet);
@@ -1929,6 +1932,7 @@ static UniValue walletpassphrase(const JSONRPCRequest& request)
pwallet->TopUpKeyPool();
pwallet->nRelockTime = GetTime() + nSleepTime;
relock_time = pwallet->nRelockTime;
}
// rpcRunLater must be called without cs_wallet held otherwise a deadlock
@@ -1940,9 +1944,11 @@ static UniValue walletpassphrase(const JSONRPCRequest& request)
// wallet before the following callback is called. If a valid shared pointer
// is acquired in the callback then the wallet is still loaded.
std::weak_ptr<CWallet> weak_wallet = wallet;
pwallet->chain().rpcRunLater(strprintf("lockwallet(%s)", pwallet->GetName()), [weak_wallet] {
pwallet->chain().rpcRunLater(strprintf("lockwallet(%s)", pwallet->GetName()), [weak_wallet, relock_time] {
if (auto shared_wallet = weak_wallet.lock()) {
LOCK(shared_wallet->cs_wallet);
// Skip if this is not the most recent rpcRunLater callback.
if (shared_wallet->nRelockTime != relock_time) return;
shared_wallet->Lock();
shared_wallet->nRelockTime = 0;
}