Reject headers that build on an invalid parent #5459

1. 
   sipa commented at 12:36 PM on December 11, 2014: member

   Noticed by @gmaxwell: a node keeps downloading blocks after a local error that caused it to treat one block as invalid.

   NOT tested.

2. laanwj added the label P2P on Dec 12, 2014
3. laanwj added this to the milestone 0.10.0 on Dec 19, 2014
4. 
   laanwj commented at 12:39 PM on December 22, 2014: member

   After having applied this I've rigged my bitcoind to fail at block 10000, with

   diff --git a/src/main.cpp b/src/main.cpp
   index 235d3e6..2a9f20b 100644
   --- a/src/main.cpp
   +++ b/src/main.cpp
   @@ -1960,6 +1961,11 @@ bool static ConnectTip(CValidationState &state, CBlockIndex *pindexNew, CBlock *
            CInv inv(MSG_BLOCK, pindexNew->GetBlockHash());
            bool rv = ConnectBlock(*pblock, state, pindexNew, view);
            g_signals.BlockChecked(*pblock, state);
   +        if (chainActive.Height() == 10000)
   +        {
   +            rv = false;
   +            state.Invalid(error("height == 10000"));
   +        }
            if (!rv) {
                if (state.IsInvalid())
                    InvalidBlockFound(pindexNew, state);
   

   But it keeps downloading: see http://www.hastebin.com/retodasuje.txt for debug.log extract.

5. Reject headers that build on an invalid parent 3497022347
6. sipa force-pushed on Dec 22, 2014
7. 
   sipa commented at 2:16 PM on December 22, 2014: member

   Updated, and tested with your patch.

   It still tries to connect the same block over and over again, but that's because the validated doesn't actually mark it as invalid.

8. 
   laanwj commented at 2:29 PM on December 22, 2014: member

   Tested ACK

9. 
   gmaxwell commented at 10:29 AM on December 23, 2014: contributor

   ACK

10. laanwj merged this on Dec 23, 2014
11. laanwj closed this on Dec 23, 2014

    ---

12. laanwj referenced this in commit 4406c3e0f4 on Dec 23, 2014
13. 
    maaku commented at 10:54 AM on December 23, 2014: contributor

    ACK (tested)

14. sipa referenced this in commit 8446262597 on Dec 23, 2014
15. MarcoFalke locked this on Sep 8, 2021

Milestone
0.10.0