Merge #12561: Check for block corruption in ConnectBlock()

0e7c52d Shut down if trying to connect a corrupted block (Suhas Daftuar)

Pull request description:

  (Updated OP after reworking the approach)

  Shut down if a corrupted block is found in ConnectBlock().  This prevents an infinite loop trying to connect such a block, and alerts the node operator that there may be potential hardware failure.

Tree-SHA512: f20d56aa9d36d6eeff4c3d13c0fbd14f06a57701bd13c2416d36f0cc4235f81f752139e336a073617e8e803782c5096c960108af122b19a51227de512e9095ee

src/validation.cpp

@@ -1793,8 +1793,15 @@ bool CChainState::ConnectBlock(const CBlock& block, CValidationState& state, CBl
     // 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, chainparams.GetConsensus(), !fJustCheck, !fJustCheck))
+    if (!CheckBlock(block, state, chainparams.GetConsensus(), !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 == nullptr ? uint256() : pindex->pprev->GetBlockHash();