From fc2ddae9655ba7680495c90ec296c333570db7b9 Mon Sep 17 00:00:00 2001 From: Tsvetomir Dimitrov Date: Tue, 22 Feb 2022 18:45:45 +0200 Subject: [PATCH] Use only fresh DisputeStatement-s for dispute spam detection (#4921) (#4957) handle_import_statements() from Dispute-Coordinator does spam detection by counting unconfirmed dispute statements from each validator. This patch adjusts the logic so that only fresh dispute statements are counted. Fresh dispute statement in this case means a statement which was not loaded from overlay db. --- .../core/dispute-coordinator/src/real/initialized.rs | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/polkadot/node/core/dispute-coordinator/src/real/initialized.rs b/polkadot/node/core/dispute-coordinator/src/real/initialized.rs index d9d71c67e9..8123aaada4 100644 --- a/polkadot/node/core/dispute-coordinator/src/real/initialized.rs +++ b/polkadot/node/core/dispute-coordinator/src/real/initialized.rs @@ -831,6 +831,9 @@ impl Initialized { .find(|(_, index)| controlled_indices.contains(index)) .is_some(); + // Indexes of the validators issued 'invalid' statements. Will be used to populate spam slots. + let mut fresh_invalid_statement_issuers = Vec::new(); + // Update candidate votes. for (statement, val_index) in &statements { if validators @@ -876,6 +879,7 @@ impl Initialized { continue } + fresh_invalid_statement_issuers.push(*val_index); votes_changed = true; self.metrics.on_invalid_vote(); }, @@ -892,17 +896,17 @@ impl Initialized { byzantine_threshold(n_validators); // Potential spam: - if !is_confirmed { + if !is_confirmed && !fresh_invalid_statement_issuers.is_empty() { let mut free_spam_slots_available = true; // Only allow import if all validators voting invalid, have not exceeded // their spam slots: - for (statement, index) in statements.iter() { + for index in fresh_invalid_statement_issuers { // Disputes can only be triggered via an invalidity stating vote, thus we only // need to increase spam slots on invalid votes. (If we did not, we would also // increase spam slots for backing validators for example - as validators have to // provide some opposing vote for dispute-distribution). - free_spam_slots_available &= statement.statement().indicates_validity() || - self.spam_slots.add_unconfirmed(session, candidate_hash, *index); + free_spam_slots_available &= + self.spam_slots.add_unconfirmed(session, candidate_hash, index); } // Only validity stating votes or validator had free spam slot? if !free_spam_slots_available {