Shut down if trying to connect a corrupted block

The call to CheckBlock() in ConnectBlock() is redundant with calls to it
prior to storing a block on disk. If CheckBlock() fails with an error
indicating the block is potentially corrupted, then shut down
immediately, as this is an indication that the node is experiencing
hardware issues.  (If we didn't shut down, we could go into an infinite
loop trying to reconnect this same bad block, as we're not setting the
block's status to FAILED in the case where there is potential
corruption.)

If CheckBlock() fails for some other reason, we'll end up flagging this
block as bad (perhaps some prior software version "let a bad block in",
as the comment indicates), and not trying to connect it again, so this
case should be properly handled.
This commit is contained in:
Suhas Daftuar 2018-03-05 10:42:26 -05:00 committed by Ross Nicoll
parent 51aca8e38d
commit 25dada932a

View file

@ -1768,8 +1768,27 @@ bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockIndex* pin
int64_t nTimeStart = GetTimeMicros();
// Check it again in case a previous version let a bad block in
if (!CheckBlock(block, state, !fJustCheck, !fJustCheck))
// NOTE: We don't currently (re-)invoke ContextualCheckBlock() or
// ContextualCheckBlockHeader() here. This means that if we add a new
// consensus rule that is enforced in one of those two functions, then we
// may have let in a block that violates the rule prior to updating the
// software, and we would NOT be enforcing the rule here. Fully solving
// upgrade from one software version to the next after a consensus rule
// change is potentially tricky and issue-specific (see RewindBlockIndex()
// for one general approach that was used for BIP 141 deployment).
// Also, currently the rule against blocks more than 2 hours in the future
// is enforced in ContextualCheckBlockHeader(); we wouldn't want to
// re-enforce that rule here (at least until we make it impossible for
// GetAdjustedTime() to go backward).
if (!CheckBlock(block, state, !fJustCheck, !fJustCheck)) {
if (state.CorruptionPossible()) {
// We don't write down blocks to disk if they may have been
// corrupted, so this should be impossible unless we're having hardware
// problems.
return AbortNode(state, "Corrupt block found indicating potential hardware failure; shutting down");
}
return error("%s: Consensus::CheckBlock: %s", __func__, FormatStateMessage(state));
}
// verify that the view's current state corresponds to the previous block
uint256 hashPrevBlock = pindex->pprev == NULL ? uint256() : pindex->pprev->GetBlockHash();