Bitcoin ABC Large Block ZeroDay Vulnerability - 01

gistfile1.txt

static bool ConnectBlock(const Config &config, const CBlock &block,
                         CValidationState &state, CBlockIndex *pindex,
                         CCoinsViewCache &view, bool fJustCheck = false) {
    ==> AssertLockHeld(cs_main);


	// ...

    ==> if (!control.Wait()) {
        return state.DoS(100, false, REJECT_INVALID, "blk-bad-inputs", false,
                         "parallel script check failed");
    }



bool SendMessages(const Config &config, CNode *pto, CConnman &connman,
                  const std::atomic<bool> &interruptMsgProc) {

	// ....

    ==> TRY_LOCK(cs_main, lockMain);

    if (!lockMain) {
        return true;
    }

Multi threading 101: get & hold lock, do stuff, release lock. Seems that's not how Bcash understood this.