diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/main.cpp | 3 | ||||
| -rw-r--r-- | src/net.cpp | 2 | ||||
| -rw-r--r-- | src/timedata.cpp | 18 | ||||
| -rw-r--r-- | src/txmempool.cpp | 7 |
4 files changed, 25 insertions, 5 deletions
diff --git a/src/main.cpp b/src/main.cpp index 84178b16e2..06ce15b5b3 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -2016,7 +2016,7 @@ static CBlockIndex* FindMostWorkChain() { CBlockIndex *pindexTest = pindexNew; bool fInvalidAncestor = false; while (pindexTest && !chainActive.Contains(pindexTest)) { - if (!pindexTest->IsValid(BLOCK_VALID_TRANSACTIONS) || !(pindexTest->nStatus & BLOCK_HAVE_DATA)) { + if (pindexTest->nStatus & BLOCK_FAILED_MASK) { // Candidate has an invalid ancestor, remove entire chain from the set. if (pindexBestInvalid == NULL || pindexNew->nChainWork > pindexBestInvalid->nChainWork) pindexBestInvalid = pindexNew; @@ -2026,6 +2026,7 @@ static CBlockIndex* FindMostWorkChain() { setBlockIndexValid.erase(pindexFailed); pindexFailed = pindexFailed->pprev; } + setBlockIndexValid.erase(pindexTest); fInvalidAncestor = true; break; } diff --git a/src/net.cpp b/src/net.cpp index 329e0278ca..6c636d16b4 100644 --- a/src/net.cpp +++ b/src/net.cpp @@ -1478,7 +1478,7 @@ bool OpenNetworkConnection(const CAddress& addrConnect, CSemaphoreGrant *grantOu if (!pszDest) { if (IsLocal(addrConnect) || FindNode((CNetAddr)addrConnect) || CNode::IsBanned(addrConnect) || - FindNode(addrConnect.ToStringIPPort().c_str())) + FindNode(addrConnect.ToStringIPPort())) return false; } else if (FindNode(pszDest)) return false; diff --git a/src/timedata.cpp b/src/timedata.cpp index 8a095d26dc..6c3bd9a48d 100644 --- a/src/timedata.cpp +++ b/src/timedata.cpp @@ -49,6 +49,24 @@ void AddTimeData(const CNetAddr& ip, int64_t nTime) static CMedianFilter<int64_t> vTimeOffsets(200,0); vTimeOffsets.input(nOffsetSample); LogPrintf("Added time data, samples %d, offset %+d (%+d minutes)\n", vTimeOffsets.size(), nOffsetSample, nOffsetSample/60); + + // There is a known issue here (see issue #4521): + // + // - The structure vTimeOffsets contains up to 200 elements, after which + // any new element added to it will not increase its size, replacing the + // oldest element. + // + // - The condition to update nTimeOffset includes checking whether the + // number of elements in vTimeOffsets is odd, which will never happen after + // there are 200 elements. + // + // But in this case the 'bug' is protective against some attacks, and may + // actually explain why we've never seen attacks which manipulate the + // clock offset. + // + // So we should hold off on fixing this and clean it up as part of + // a timing cleanup that strengthens it in a number of other ways. + // if (vTimeOffsets.size() >= 5 && vTimeOffsets.size() % 2 == 1) { int64_t nMedian = vTimeOffsets.median(); diff --git a/src/txmempool.cpp b/src/txmempool.cpp index ebb1369e31..164e2741a2 100644 --- a/src/txmempool.cpp +++ b/src/txmempool.cpp @@ -602,14 +602,15 @@ void CTxMemPool::ClearPrioritisation(const uint256 hash) CCoinsViewMemPool::CCoinsViewMemPool(CCoinsView &baseIn, CTxMemPool &mempoolIn) : CCoinsViewBacked(baseIn), mempool(mempoolIn) { } bool CCoinsViewMemPool::GetCoins(const uint256 &txid, CCoins &coins) { - if (base->GetCoins(txid, coins)) - return true; + // If an entry in the mempool exists, always return that one, as it's guaranteed to never + // conflict with the underlying cache, and it cannot have pruned entries (as it contains full) + // transactions. First checking the underlying cache risks returning a pruned entry instead. CTransaction tx; if (mempool.lookup(txid, tx)) { coins = CCoins(tx, MEMPOOL_HEIGHT); return true; } - return false; + return (base->GetCoins(txid, coins) && !coins.IsPruned()); } bool CCoinsViewMemPool::HaveCoins(const uint256 &txid) { |