Add feature flag to blacklist blocks (#15030)

* Add feature flag to blacklist blocks

* review and add tests

* add test

* review

* Kasey's review

---------

Co-authored-by: Radosław Kapka <rkapka@wp.pl>

beacon-chain/blockchain/error.go

@@ -32,6 +32,8 @@ var (
 	ErrNilHead = errors.New("nil head")
 	// errNotGenesisRoot is returned when the root is not the genesis block root.
 	errNotGenesisRoot = errors.New("root is not the genesis block root")
+	// errBlacklistedBlock is returned when a block is blacklisted as invalid.
+	errBlacklistedRoot = errors.New("block root is blacklisted")
 )
 
 var errMaxBlobsExceeded = errors.New("Expected commitments in block exceeds MAX_BLOBS_PER_BLOCK")

beacon-chain/blockchain/process_block.go

@@ -175,6 +175,9 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlo
 	var set *bls.SignatureBatch
 	boundaries := make(map[[32]byte]state.BeaconState)
 	for i, b := range blks {
+		if features.BlacklistedBlock(b.Root()) {
+			return errBlacklistedRoot
+		}
 		v, h, err := getStateVersionAndPayload(preState)
 		if err != nil {
 			return err

beacon-chain/blockchain/receive_block.go

@@ -16,6 +16,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/das"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/slasher/types"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/v5/config/features"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
@@ -64,6 +65,10 @@ type SlashingReceiver interface {
 func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte, avs das.AvailabilityStore) error {
 	ctx, span := trace.StartSpan(ctx, "blockChain.ReceiveBlock")
 	defer span.End()
+	// Return early if the block is blacklisted
+	if features.BlacklistedBlock(blockRoot) {
+		return errBlacklistedRoot
+	}
 	// Return early if the block has been synced
 	if s.InForkchoice(blockRoot) {
 		log.WithField("blockRoot", fmt.Sprintf("%#x", blockRoot)).Debug("Ignoring already synced block")

beacon-chain/blockchain/receive_block_test.go

@@ -12,6 +12,7 @@ import (
 	statefeed "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/feed/state"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/das"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/operations/voluntaryexits"
+	"github.com/prysmaticlabs/prysm/v5/config/features"
 	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
@@ -41,6 +42,16 @@ func TestService_ReceiveBlock(t *testing.T) {
 	bc.ShardCommitteePeriod = 0 // Required for voluntary exits test in reasonable time.
 	params.OverrideBeaconConfig(bc)
 
+	badBlock := genFullBlock(t, util.DefaultBlockGenConfig(), 101)
+	badRoot, err := badBlock.Block.HashTreeRoot()
+	require.NoError(t, err)
+	badRoots := make(map[[32]byte]struct{})
+	badRoots[badRoot] = struct{}{}
+	resetCfg := features.InitWithReset(&features.Flags{
+		BlacklistedRoots: badRoots,
+	})
+	defer resetCfg()
+
 	type args struct {
 		block *ethpb.SignedBeaconBlock
 	}
@@ -124,8 +135,14 @@ func TestService_ReceiveBlock(t *testing.T) {
 				}
 			},
 		},
+		{
+			name: "The block is blacklisted",
+			args: args{
+				block: badBlock,
+			},
+			wantedErr: errBlacklistedRoot.Error(),
+		},
 	}
-
 	wg := new(sync.WaitGroup)
 	for _, tt := range tests {
 		wg.Add(1)

beacon-chain/sync/initial-sync/BUILD.bazel

@@ -32,6 +32,7 @@ go_library(
         "//beacon-chain/sync/verify:go_default_library",
         "//beacon-chain/verification:go_default_library",
         "//cmd/beacon-chain/flags:go_default_library",
+        "//config/features:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",
         "//consensus-types/interfaces:go_default_library",

beacon-chain/sync/initial-sync/blocks_fetcher.go

@@ -18,6 +18,7 @@ import (
 	prysmsync "github.com/prysmaticlabs/prysm/v5/beacon-chain/sync"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/sync/verify"
 	"github.com/prysmaticlabs/prysm/v5/cmd/beacon-chain/flags"
+	"github.com/prysmaticlabs/prysm/v5/config/features"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
@@ -357,6 +358,13 @@ func (f *blocksFetcher) fetchBlocksFromPeer(
 			log.WithField("peer", p).WithError(err).Debug("invalid BeaconBlocksByRange response")
 			continue
 		}
+		if len(features.Get().BlacklistedRoots) > 0 {
+			for _, b := range robs {
+				if features.BlacklistedBlock(b.Block.Root()) {
+					return nil, p, prysmsync.ErrInvalidFetchedData
+				}
+			}
+		}
 		return robs, p, err
 	}
 	return nil, "", errNoPeersAvailable

beacon-chain/sync/validate_beacon_blocks.go

@@ -16,6 +16,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/transition"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/v5/config/features"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	consensusblocks "github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
@@ -409,6 +410,9 @@ func (s *Service) setSeenBlockIndexSlot(slot primitives.Slot, proposerIdx primit
 
 // Returns true if the block is marked as a bad block.
 func (s *Service) hasBadBlock(root [32]byte) bool {
+	if features.BlacklistedBlock(root) {
+		return true
+	}
 	s.badBlockLock.RLock()
 	defer s.badBlockLock.RUnlock()
 	_, seen := s.badBlockCache.Get(string(root[:]))

changelog/potuz_blacklist.md

@@ -0,0 +1,3 @@
+### Added
+
+- Add a feature flag `--blacklist-roots` to allow the node to specify blocks that will be treated as invalid. 

config/features/BUILD.bazel

@@ -14,6 +14,7 @@ go_library(
         "//cmd:go_default_library",
         "//cmd/beacon-chain/sync/backfill/flags:go_default_library",
         "//config/params:go_default_library",
+        "//encoding/bytesutil:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
         "@com_github_urfave_cli_v2//:go_default_library",
     ],
@@ -30,6 +31,7 @@ go_test(
     deps = [
         "//testing/assert:go_default_library",
         "//testing/require:go_default_library",
+        "@com_github_sirupsen_logrus//hooks/test:go_default_library",
         "@com_github_urfave_cli_v2//:go_default_library",
     ],
 )

config/features/config.go

@@ -27,6 +27,7 @@ import (
 
 	"github.com/prysmaticlabs/prysm/v5/cmd"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
+	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	"github.com/sirupsen/logrus"
 	"github.com/urfave/cli/v2"
 )
@@ -88,7 +89,8 @@ type Flags struct {
 	AggregateIntervals [3]time.Duration
 
 	// Feature related flags (alignment forced in the end)
-	ForceHead string // ForceHead forces the head block to be a specific block root, the last head block, or the last finalized block.
+	ForceHead        string                // ForceHead forces the head block to be a specific block root, the last head block, or the last finalized block.
+	BlacklistedRoots map[[32]byte]struct{} // BlacklistedRoots is a list of roots that are blacklisted from processing.
 }
 
 var featureConfig *Flags
@@ -282,11 +284,29 @@ func ConfigureBeaconChain(ctx *cli.Context) error {
 		cfg.ForceHead = ctx.String(forceHeadFlag.Name)
 	}
 
+	if ctx.IsSet(blacklistRoots.Name) {
+		logEnabled(blacklistRoots)
+		cfg.BlacklistedRoots = parseBlacklistedRoots(ctx.StringSlice(blacklistRoots.Name))
+	}
+
 	cfg.AggregateIntervals = [3]time.Duration{aggregateFirstInterval.Value, aggregateSecondInterval.Value, aggregateThirdInterval.Value}
 	Init(cfg)
 	return nil
 }
 
+func parseBlacklistedRoots(blacklistedRoots []string) map[[32]byte]struct{} {
+	roots := make(map[[32]byte]struct{})
+	for _, root := range blacklistedRoots {
+		r, err := bytesutil.DecodeHexWithLength(root, 32)
+		if err != nil {
+			log.WithError(err).WithField("root", root).Warn("Failed to parse blacklisted root")
+			continue
+		}
+		roots[[32]byte(r)] = struct{}{}
+	}
+	return roots
+}
+
 // ConfigureValidator sets the global config based
 // on what flags are enabled for the validator client.
 func ConfigureValidator(ctx *cli.Context) error {
@@ -398,3 +418,10 @@ func ValidateNetworkFlags(ctx *cli.Context) error {
 	}
 	return nil
 }
+
+// BlacklistedBlock returns weather the given block root belongs to the list of blacklisted roots.
+func BlacklistedBlock(r [32]byte) bool {
+	blacklisted := Get().BlacklistedRoots
+	_, ok := blacklisted[r]
+	return ok
+}

config/features/config_test.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/prysmaticlabs/prysm/v5/testing/assert"
 	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/sirupsen/logrus/hooks/test"
 	"github.com/urfave/cli/v2"
 )
 
@@ -93,3 +94,26 @@ func TestValidateNetworkFlags(t *testing.T) {
 		})
 	}
 }
+
+func Test_parseBlacklistedRoots(t *testing.T) {
+	strings := []string{"0xf98e27558ac9ba27ab7d0d3b97d5742a4a68b5e3d7f33c520eda14c39df6368c",
+		"0x31604da144e1047b250ee87c5049774870e4a140e8eb0087f38ebc4584c2e7",
+		"0x4fcf04e7e4075962360a91be0c54c1d3f67237aa2ce07d83b0479971af3f7e78",
+	}
+	hook := test.NewGlobal()
+	resCfg := InitWithReset(&Flags{
+		BlacklistedRoots: parseBlacklistedRoots(strings),
+	})
+	defer resCfg()
+
+	expected := [][32]byte{
+		{0xf9, 0x8e, 0x27, 0x55, 0x8a, 0xc9, 0xba, 0x27, 0xab, 0x7d, 0x0d, 0x3b, 0x97, 0xd5, 0x74, 0x2a, 0x4a, 0x68, 0xb5, 0xe3, 0xd7, 0xf3, 0x3c, 0x52, 0x0e, 0xda, 0x14, 0xc3, 0x9d, 0xf6, 0x36, 0x8c},
+		{0x4f, 0xcf, 0x04, 0xe7, 0xe4, 0x07, 0x59, 0x62, 0x36, 0x0a, 0x91, 0xbe, 0x0c, 0x54, 0xc1, 0xd3, 0xf6, 0x72, 0x37, 0xaa, 0x2c, 0xe0, 0x7d, 0x83, 0xb0, 0x47, 0x99, 0x71, 0xaf, 0x3f, 0x7e, 0x78},
+	}
+	require.LogsContain(t, hook, "Failed to parse blacklisted root")
+	require.LogsContain(t, hook, strings[1])
+	require.Equal(t, len(expected), len(Get().BlacklistedRoots))
+	for _, root := range expected {
+		require.Equal(t, true, BlacklistedBlock(root))
+	}
+}

config/features/flags.go

@@ -185,6 +185,12 @@ var (
 		Usage: "Forces the head of the beacon chain to a specific block root. Values can be 'head' or a block root." +
 			" The block root has to be known to the beacon node and correspond to a block newer than the current finalized checkpoint.",
 	}
+	// blacklistRoots is a flag for blacklisting block roots from gossip and
+	// downscore peers that send them.
+	blacklistRoots = &cli.StringSliceFlag{
+		Name:  "blacklist-roots",
+		Usage: "A comma-separatted list of 0x-prefixed hexstrings. Declares blocks with the given blockroots to be invalid. It downscores peers that send these blocks.",
+	}
 )
 
 // devModeFlags holds list of flags that are set when development mode is on.
@@ -244,6 +250,7 @@ var BeaconChainFlags = combinedFlags([]cli.Flag{
 	EnableDiscoveryReboot,
 	enableExperimentalAttestationPool,
 	forceHeadFlag,
+	blacklistRoots,
 }, deprecatedBeaconFlags, deprecatedFlags, upcomingDeprecation)
 
 func combinedFlags(flags ...[]cli.Flag) []cli.Flag {