Sanity assert GetAncestor() != nullptr where appropriate

Add sanity asserts for return value of `CBlockIndex::GetAncestor()` where appropriate.

In validation.cpp `CheckSequenceLocks`, check the return value of `tip->GetAncestor(maxInputHeight)` stored into `lp->maxInputBlock`. If it ever returns `nullptr` because the ancestor isn't found, it's going to be a bad bug to keep going, since a `LockPoints` object with the `maxInputBlock` member set to `nullptr` signifies no relative lock time.

In the other places, the added asserts would prevent accidental dereferencing of a null pointer which is undefined behavior.

Co-Authored-By: Aurèle Oulès <aurele@oules.com>
Co-Authored-By: danra <danra@users.noreply.github.com>
This commit is contained in:
Adam Jonas
2019-10-21 13:17:22 -04:00
committed by Aurèle Oulès
parent b1c5991eeb
commit 308dd2e93e
5 changed files with 39 additions and 28 deletions

View File

@@ -446,16 +446,18 @@ BOOST_AUTO_TEST_CASE(CreateNewBlock_validity)
BOOST_CHECK(CheckFinalTxAtTip(m_node.chainman->ActiveChain().Tip(), CTransaction{tx})); // Locktime passes
BOOST_CHECK(!TestSequenceLocks(CTransaction{tx})); // Sequence locks fail
for (int i = 0; i < CBlockIndex::nMedianTimeSpan; i++)
m_node.chainman->ActiveChain().Tip()->GetAncestor(m_node.chainman->ActiveChain().Tip()->nHeight - i)->nTime += 512; //Trick the MedianTimePast
const int SEQUENCE_LOCK_TIME = 512; // Sequence locks pass 512 seconds later
for (int i = 0; i < CBlockIndex::nMedianTimeSpan; ++i)
m_node.chainman->ActiveChain().Tip()->GetAncestor(m_node.chainman->ActiveChain().Tip()->nHeight - i)->nTime += SEQUENCE_LOCK_TIME; // Trick the MedianTimePast
{
CBlockIndex* active_chain_tip = m_node.chainman->ActiveChain().Tip();
BOOST_CHECK(SequenceLocks(CTransaction(tx), flags, prevheights, CreateBlockIndex(active_chain_tip->nHeight + 1, active_chain_tip))); // Sequence locks pass 512 seconds later
BOOST_CHECK(SequenceLocks(CTransaction(tx), flags, prevheights, CreateBlockIndex(active_chain_tip->nHeight + 1, active_chain_tip)));
}
for (int i = 0; i < CBlockIndex::nMedianTimeSpan; i++)
m_node.chainman->ActiveChain().Tip()->GetAncestor(m_node.chainman->ActiveChain().Tip()->nHeight - i)->nTime -= 512; //undo tricked MTP
for (int i = 0; i < CBlockIndex::nMedianTimeSpan; ++i) {
CBlockIndex* ancestor{Assert(m_node.chainman->ActiveChain().Tip()->GetAncestor(m_node.chainman->ActiveChain().Tip()->nHeight - i))};
ancestor->nTime -= SEQUENCE_LOCK_TIME; // undo tricked MTP
}
// absolute height locked
tx.vin[0].prevout.hash = txFirst[2]->GetHash();
@@ -500,9 +502,11 @@ BOOST_AUTO_TEST_CASE(CreateNewBlock_validity)
// but relative locked txs will if inconsistently added to mempool.
// For now these will still generate a valid template until BIP68 soft fork
BOOST_CHECK_EQUAL(pblocktemplate->block.vtx.size(), 3U);
// However if we advance height by 1 and time by 512, all of them should be mined
for (int i = 0; i < CBlockIndex::nMedianTimeSpan; i++)
m_node.chainman->ActiveChain().Tip()->GetAncestor(m_node.chainman->ActiveChain().Tip()->nHeight - i)->nTime += 512; //Trick the MedianTimePast
// However if we advance height by 1 and time by SEQUENCE_LOCK_TIME, all of them should be mined
for (int i = 0; i < CBlockIndex::nMedianTimeSpan; ++i) {
CBlockIndex* ancestor{Assert(m_node.chainman->ActiveChain().Tip()->GetAncestor(m_node.chainman->ActiveChain().Tip()->nHeight - i))};
ancestor->nTime += SEQUENCE_LOCK_TIME; // Trick the MedianTimePast
}
m_node.chainman->ActiveChain().Tip()->nHeight++;
SetMockTime(m_node.chainman->ActiveChain().Tip()->GetMedianTimePast() + 1);