hyperledger/fabric · error

Invalid block's channel id. Expected [%s]. Given [%s]

Error message

Invalid block's channel id. Expected [%s]. Given [%s]

What it means

VerifyBlock checks that the block's channel ID (extracted from its header/metadata) matches the channel on which the block was claimed. This error reports the expected channel vs the channel encoded in the block. It is a security check preventing cross-channel block injection via gossip.

Source

Thrown at internal/peer/gossip/mcs.go:145

// else returns error
func (s *MSPMessageCryptoService) VerifyBlock(chainID common.ChannelID, seqNum uint64, block *pcommon.Block) error {
	if block.Header == nil {
		return fmt.Errorf("Invalid Block on channel [%s]. Header must be different from nil.", chainID)
	}

	blockSeqNum := block.Header.Number
	if seqNum != blockSeqNum {
		return fmt.Errorf("Claimed seqNum is [%d] but actual seqNum inside block is [%d]", seqNum, blockSeqNum)
	}

	// - Extract channelID and compare with chainID
	channelID, err := protoutil.GetChannelIDFromBlock(block)
	if err != nil {
		return fmt.Errorf("Failed getting channel id from block with id [%d] on channel [%s]: [%s]", block.Header.Number, chainID, err)
	}

	if channelID != string(chainID) {
		return fmt.Errorf("Invalid block's channel id. Expected [%s]. Given [%s]", chainID, channelID)
	}

	// - Unmarshal medatada
	if block.Metadata == nil || len(block.Metadata.Metadata) == 0 {
		return fmt.Errorf("Block with id [%d] on channel [%s] does not have metadata. Block not valid.", block.Header.Number, chainID)
	}

	dataHash, err := protoutil.BlockDataHash(block.Data)
	if err != nil {
		return err
	}
	// - Verify that Header.DataHash is equal to the hash of block.Data
	// This is to ensure that the header is consistent with the data carried by this block
	if !bytes.Equal(dataHash, block.Header.DataHash) {
		return fmt.Errorf("Header.DataHash is different from Hash(block.Data) for block with id [%d] on channel [%s]", block.Header.Number, chainID)
	}

	return s.verifyHeaderAndMetadata(channelID, block)

View on GitHub (pinned to 2736b63f8f)

Solutions

1. Ensure the caller passes the channel ID that matches the block's origin channel
2. Check gossip membership/config — the peer may have stale state for a deleted or recreated channel
3. Inspect the block with configtxlator or a decoder to confirm its true channel

func assertChannel(b *pcommon.Block, chainID common.ChannelID) error {
    ch, err := protoutil.GetChannelIDFromBlock(b)
    if err != nil {
        return err
    }
    if ch != string(chainID) {
        return fmt.Errorf("block belongs to channel %s, expected %s", ch, chainID)
    }
    return nil
}

func belongsToChannel(b *pcommon.Block, chainID common.ChannelID) bool {
    ch, err := protoutil.GetChannelIDFromBlock(b)
    return err == nil && ch == string(chainID)
}

if !belongsToChannel(block, chainID) {
    return errors.New("block/channel mismatch, refusing verify")
}

if err := cryptoService.VerifyBlock(chainID, seqNum, block); err != nil {
    if strings.Contains(err.Error(), "Invalid block's channel id") {
        log.Errorf("possible cross-channel injection on %s: %v", chainID, err)
        return err
    }
    return err
}

When it happens

Trigger: VerifyBlock(chainID, seq, block) where block's embedded channelID differs from string(chainID) — e.g. block pulled from channel A but validated against channel B.

Common situations: Malicious or buggy peer sending blocks across channels; developer wiring wrong channel name when programmatically invoking the crypto service; channel renamed/recreated while peer still holds old blocks.

Related errors

• Failed getting channel id from block with id [%d] on channel
• chaincode %s attempted to write to the namespace of LSCC
• failed unmarshalling alive message
• failed unmarshalling stateInfo message
• wasn't able to read ledger height

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/4bf02a50167ba30e. Report an issue: GitHub.