Compare with nil before invoking IsNil() on an interface (#14431)

* Compare with nil before invoking `IsNil()` on an interface

* changelog

* review

CHANGELOG.md

@@ -46,6 +46,7 @@ The format is based on Keep a Changelog, and this project adheres to Semantic Ve
 - E2E: fixed gas limit at genesis
 - Light client support: use LightClientHeader instead of BeaconBlockHeader.
 - Core: Fix process effective balance update to safe copy validator for Electra.
+- `== nil` checks before calling `IsNil()` on interfaces to prevent panics.
 
 ### Security
 

beacon-chain/blockchain/execution_engine.go

@@ -39,7 +39,7 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *fcuConfig) (*
 	ctx, span := trace.StartSpan(ctx, "blockChain.notifyForkchoiceUpdate")
 	defer span.End()
 
-	if arg.headBlock.IsNil() {
+	if arg.headBlock == nil || arg.headBlock.IsNil() {
 		log.Error("Head block is nil")
 		return nil, nil
 	}

beacon-chain/blockchain/pow_block.go

@@ -46,7 +46,7 @@ func (s *Service) validateMergeBlock(ctx context.Context, b interfaces.ReadOnlyS
 	if err != nil {
 		return err
 	}
-	if payload.IsNil() {
+	if payload == nil || payload.IsNil() {
 		return errors.New("nil execution payload")
 	}
 	ok, err := canUseValidatedTerminalBlockHash(b.Block().Slot(), payload)

beacon-chain/execution/engine_client.go

@@ -526,7 +526,7 @@ func (s *Service) ReconstructFullBellatrixBlockBatch(
 func fullPayloadFromPayloadBody(
 	header interfaces.ExecutionData, body *pb.ExecutionPayloadBody, bVersion int,
 ) (interfaces.ExecutionData, error) {
-	if header.IsNil() || body == nil {
+	if header == nil || header.IsNil() || body == nil {
 		return nil, errors.New("execution block and header cannot be nil")
 	}
 

beacon-chain/execution/payload_body.go

@@ -67,7 +67,7 @@ func (r *blindedBlockReconstructor) addToBatch(b interfaces.ReadOnlySignedBeacon
 	if err != nil {
 		return err
 	}
-	if header.IsNil() {
+	if header == nil || header.IsNil() {
 		return errors.New("execution payload header in blinded block was nil")
 	}
 	r.orderedBlocks = append(r.orderedBlocks, &blockWithHeader{block: b, header: header})

beacon-chain/rpc/prysm/v1alpha1/validator/proposer_bellatrix.go

@@ -198,7 +198,7 @@ func (vs *Server) getPayloadHeaderFromBuilder(ctx context.Context, slot primitiv
 	if err != nil {
 		return nil, err
 	}
-	if signedBid.IsNil() {
+	if signedBid == nil || signedBid.IsNil() {
 		return nil, errors.New("builder returned nil bid")
 	}
 	fork, err := forks.Fork(slots.ToEpoch(slot))
@@ -217,7 +217,7 @@ func (vs *Server) getPayloadHeaderFromBuilder(ctx context.Context, slot primitiv
 	if err != nil {
 		return nil, errors.Wrap(err, "could not get bid")
 	}
-	if bid.IsNil() {
+	if bid == nil || bid.IsNil() {
 		return nil, errors.New("builder returned nil bid")
 	}
 
@@ -309,14 +309,14 @@ func validateBuilderSignature(signedBid builder.SignedBid) error {
 	if err != nil {
 		return err
 	}
-	if signedBid.IsNil() {
+	if signedBid == nil || signedBid.IsNil() {
 		return errors.New("nil builder bid")
 	}
 	bid, err := signedBid.Message()
 	if err != nil {
 		return errors.Wrap(err, "could not get bid")
 	}
-	if bid.IsNil() {
+	if bid == nil || bid.IsNil() {
 		return errors.New("builder returned nil bid")
 	}
 	return signing.VerifySigningRoot(bid, bid.Pubkey(), signedBid.Signature(), d)

beacon-chain/rpc/prysm/v1alpha1/validator/status.go

@@ -402,16 +402,13 @@ func statusForPubKey(headState state.ReadOnlyBeaconState, pubKey []byte) (ethpb.
 
 func assignmentStatus(beaconState state.ReadOnlyBeaconState, validatorIndex primitives.ValidatorIndex) ethpb.ValidatorStatus {
 	validator, err := beaconState.ValidatorAtIndexReadOnly(validatorIndex)
-	if err != nil {
+	if err != nil || validator.IsNil() {
 		return ethpb.ValidatorStatus_UNKNOWN_STATUS
 	}
+
 	currentEpoch := time.CurrentEpoch(beaconState)
 	farFutureEpoch := params.BeaconConfig().FarFutureEpoch
 	validatorBalance := validator.EffectiveBalance()
-
-	if validator.IsNil() {
-		return ethpb.ValidatorStatus_UNKNOWN_STATUS
-	}
 	if currentEpoch < validator.ActivationEligibilityEpoch() {
 		return depositStatus(validatorBalance)
 	}

beacon-chain/sync/validate_beacon_blocks.go

@@ -345,7 +345,7 @@ func (s *Service) validateBellatrixBeaconBlock(ctx context.Context, parentState
 	if err != nil {
 		return err
 	}
-	if payload.IsNil() {
+	if payload == nil || payload.IsNil() {
 		return errors.New("execution payload is nil")
 	}
 	if payload.Timestamp() != uint64(t.Unix()) {

consensus-types/blocks/getters.go

@@ -276,7 +276,7 @@ func (b *SignedBeaconBlock) ToBlinded() (interfaces.ReadOnlySignedBeaconBlock, e
 }
 
 func (b *SignedBeaconBlock) Unblind(e interfaces.ExecutionData) error {
-	if e.IsNil() {
+	if e == nil || e.IsNil() {
 		return errors.New("cannot unblind with nil execution data")
 	}
 	if !b.IsBlinded() {

testing/endtoend/evaluators/validator.go

@@ -233,7 +233,7 @@ func validatorsSyncParticipation(_ *types.EvaluationContext, conns ...*grpc.Clie
 			return errors.Wrapf(err, "block type doesn't exist for block at epoch %d", lowestBound)
 		}
 
-		if b.IsNil() {
+		if b == nil || b.IsNil() {
 			return errors.New("nil block provided")
 		}
 		forkStartSlot, err := slots.EpochStart(params.BeaconConfig().AltairForkEpoch)
@@ -274,7 +274,7 @@ func validatorsSyncParticipation(_ *types.EvaluationContext, conns ...*grpc.Clie
 			return errors.Wrapf(err, "block type doesn't exist for block at epoch %d", lowestBound)
 		}
 
-		if b.IsNil() {
+		if b == nil || b.IsNil() {
 			return errors.New("nil block provided")
 		}
 		forkSlot, err := slots.EpochStart(params.BeaconConfig().AltairForkEpoch)