LBRYCommunity/lbrycrd
1
0
Fork 0
Code Issues 29 Pull requests 1 Projects Releases 32 Packages Wiki Activity

Longer term workaround for chainstate corruption from negative versions.

Browse source 
This also makes negative transaction versions non-standard.

This avoids an issue triggered in block 256818 where transactions with
negative version numbers were incorrectly serialized into the UTXO set.

On restart nodes detect the inconsistency and refuse to start so long as
a block with these transactions is inside the self-consistency check
window, logging "coin database inconsistencies found". The software
recommends reindexing, but reindexing does not correct the problem.

This should be fixed by changing the chainstate serialization, but
working around it seems harmless for now because the version is not
used by any network rule currently.

A patch free workaround is to start with -checklevel=2 which skips
the consistency checks, but the IsStandard change is important for
miners in order to protect unpatched nodes.
This commit is contained in:
Gregory Maxwell 2013-09-09 02:11:11 -07:00
parent 4c723841e2
commit f8b7aa8625
1 changed files with 6 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

7
src/main.cpp
View file

@ -466,7 +466,7 @@ unsigned int LimitOrphanTxSize(unsigned int nMaxOrphans)
bool IsStandardTx(const CTransaction& tx, string& reason) bool IsStandardTx(const CTransaction& tx, string& reason)
{ {
if (tx.nVersion > CTransaction::CURRENT_VERSION) { if (tx.nVersion > CTransaction::CURRENT_VERSION || tx.nVersion < 1) {
reason = "version"; reason = "version";
return false; return false;
} }
@ -1778,6 +1778,11 @@ bool DisconnectBlock(CBlock& block, CValidationState& state, CBlockIndex* pindex
CCoins &outs = view.GetCoins(hash); CCoins &outs = view.GetCoins(hash);
CCoins outsBlock = CCoins(tx, pindex->nHeight); CCoins outsBlock = CCoins(tx, pindex->nHeight);
// The CCoins serialization does not serialize negative numbers.
// No network rules currently depend on the version here, so an inconsistency is harmless
// but it must be corrected before txout nversion ever influences a network rule.
if (outsBlock.nVersion < 0)
outs.nVersion = outsBlock.nVersion;
if (outs != outsBlock) if (outs != outsBlock)
fClean = fClean && error("DisconnectBlock() : added transaction mismatch? database corrupted"); fClean = fClean && error("DisconnectBlock() : added transaction mismatch? database corrupted");