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fix: ignore PTC votes whose slot does not match the referenced block #9425

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Merged
wemeetagain merged 1 commit into from
May 30, 2026
Merged

fix: ignore PTC votes whose slot does not match the referenced block #9425

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1 change: 1 addition & 0 deletions packages/beacon-node/src/api/impl/beacon/pool/index.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -328,6 +328,7 @@ export function getBeaconPoolApi({

chain.forkChoice.notifyPtcMessages(
toRootHex(payloadAttestationMessage.data.beaconBlockRoot),
payloadAttestationMessage.data.slot,
validatorCommitteeIndices,
payloadAttestationMessage.data.payloadPresent,
payloadAttestationMessage.data.blobDataAvailable
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1 change: 1 addition & 0 deletions packages/beacon-node/src/chain/blocks/importBlock.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -263,6 +263,7 @@ export async function importBlock(
if (ptcIndices.length > 0) {
this.forkChoice.notifyPtcMessages(
toRootHex(payloadAttestation.data.beaconBlockRoot),
payloadAttestation.data.slot,
ptcIndices,
payloadAttestation.data.payloadPresent,
payloadAttestation.data.blobDataAvailable
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1 change: 1 addition & 0 deletions packages/beacon-node/src/network/processor/gossipHandlers.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -1214,6 +1214,7 @@ function getSequentialHandlers(modules: ValidatorFnsModules, options: GossipHand
}
chain.forkChoice.notifyPtcMessages(
toRootHex(payloadAttestationMessage.data.beaconBlockRoot),
payloadAttestationMessage.data.slot,
validationResult.validatorCommitteeIndices,
payloadAttestationMessage.data.payloadPresent,
payloadAttestationMessage.data.blobDataAvailable
Expand Down
3 changes: 2 additions & 1 deletion packages/fork-choice/src/forkChoice/forkChoice.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -947,11 +947,12 @@ export class ForkChoice implements IForkChoice {
*/
notifyPtcMessages(
blockRoot: RootHex,
slot: Slot,
ptcIndices: number[],
payloadPresent: boolean,
blobDataAvailable: boolean
): void {
this.protoArray.notifyPtcMessages(blockRoot, ptcIndices, payloadPresent, blobDataAvailable);
this.protoArray.notifyPtcMessages(blockRoot, slot, ptcIndices, payloadPresent, blobDataAvailable);
}

/**
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1 change: 1 addition & 0 deletions packages/fork-choice/src/forkChoice/interface.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -194,6 +194,7 @@ export interface IForkChoice {
*/
notifyPtcMessages(
blockRoot: RootHex,
slot: Slot,
ptcIndices: number[],
payloadPresent: boolean,
blobDataAvailable: boolean
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8 changes: 8 additions & 0 deletions packages/fork-choice/src/protoArray/protoArray.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -678,6 +678,7 @@ export class ProtoArray {
*/
notifyPtcMessages(
blockRoot: RootHex,
slot: Slot,
ptcIndices: number[],
payloadPresent: boolean,
blobDataAvailable: boolean
Expand All @@ -690,6 +691,13 @@ export class ProtoArray {
return;
}

// PTC votes can only change the vote for their assigned beacon block, return early otherwise
const nodeIndex = this.getDefaultNodeIndex(blockRoot);
const node = nodeIndex !== undefined ? this.getNodeByIndex(nodeIndex) : undefined;
if (node === undefined || node.slot !== slot) {
return;
Comment on lines +697 to +698
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@chatgpt-codex-connector chatgpt-codex-connector Bot May 30, 2026

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P2 Badge Reject slot-mismatched PTC messages before side effects

When this new branch returns for data.slot != block.slot, gossip/API validation has already treated the message as valid: validatePayloadAttestationMessage() only checks that the block root is known, verifies the signature against data.slot, and then adds the validator to seenPayloadAttesters; the API/gossip handlers also insert it into the payload-attestation pool before calling here. In the skipped-slot case the local validator API can produce exactly this shape by returning the closest prior canonical block with the current slot, so the message is then silently ignored by fork choice but still consumes the validator's per-epoch dedup and can be pooled/published. Please move this slot/root check into validation before marking seen/inserting, or make this call report that the message was ignored so callers can avoid those side effects.

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@nflaig nflaig May 30, 2026

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}

for (const ptcIndex of ptcIndices) {
if (ptcIndex < 0 || ptcIndex >= PTC_SIZE) {
throw new Error(`Invalid PTC index: ${ptcIndex}, must be 0..${PTC_SIZE - 1}`);
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113 changes: 73 additions & 40 deletions packages/fork-choice/test/unit/protoArray/gloas.test.ts
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