jackc/pgx · error

Received an invalid size for an inet

Error message

Received an invalid size for an inet: %d

What it means

A binary inet/cidr value must be exactly 8 bytes (IPv4) or 20 bytes (IPv6); the server sent a different length. The malformed inet binary representation is at fault, indicating protocol corruption or a non-inet value decoded as inet.

Solutions

  1. Treat as protocol/data corruption — verify the column is inet/cidr
  2. Check for driver/server version mismatch or wire tampering
Defensive patterns

Strategy: validation

When it happens

Trigger: Thrown at pgtype/inet.go:156 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of jackc/pgx@ec1a0befd2 (2026-08-04). Data as JSON: /api/errors/c9a77cc99ce2ece8. Report an issue: GitHub.

Appendix: source

Thrown at pgtype/inet.go:156

	if !prefix.IsValid() {
		return nil, nil
	}

	return prefix, nil
}

type scanPlanBinaryInetToNetipPrefixScanner struct{}

func (scanPlanBinaryInetToNetipPrefixScanner) Scan(src []byte, dst any) error {
	scanner := (dst).(NetipPrefixScanner)

	if src == nil {
		return scanner.ScanNetipPrefix(netip.Prefix{})
	}

	if len(src) != 8 && len(src) != 20 {
		return fmt.Errorf("Received an invalid size for an inet: %d", len(src))
	}

	// ignore family
	bits := src[1]
	// ignore is_cidr
	// ignore addressLength - implicit in length of message

	addr, ok := netip.AddrFromSlice(src[4:])
	if !ok {
		return errors.New("netip.AddrFromSlice failed")
	}

	return scanner.ScanNetipPrefix(netip.PrefixFrom(addr, int(bits)))
}

type scanPlanTextAnyToNetipPrefixScanner struct{}

func (scanPlanTextAnyToNetipPrefixScanner) Scan(src []byte, dst any) error {

View on GitHub (pinned to ec1a0befd2)