DNS lookup failed when enabled both Early data in websocket transport and multiplexing

[socketcat]

Operating system

macOS

System version

14.4.1

Installation type

Original sing-box Command Line

If you are using a graphical client, please provide the version of the client.

No response

Version

sing-box version 1.9.0-rc.16

Environment: go1.22.2 darwin/arm64
Tags: with_gvisor,with_quic,with_dhcp,with_wireguard,with_ech,with_utls,with_reality_server,with_acme,with_clash_api
Revision: 619aad076c730b90621b6008640fe4983a0cf0e6
CGO: disabled

Description

When using V2Ray's websocket transport, enabling both Early Data and multiplexing (with smux or yamux protocol) will cause outbound name resolution to fail.
h2mux is unaffected.

Reproduction

Using the config below and start sing-box client.
Client config:

{
  "log": {
    "level": "trace"
  },
  "dns": {
    "servers": [
      {
        "tag": "alidns",
        "address": "223.5.5.5",
        "detour": "direct"
      }
    ]
  },
  "inbounds": [
    {
      "listen": "127.0.0.1",
      "listen_port": 2080,
      "tag": "mixed-in",
      "type": "mixed"
    }
  ],
  "outbounds": [
    {
      "server": "www.example.com",
      "server_port": 443,
      "tag": "www.example.com",
      "tls": {
        "enabled": true,
        "server_name": "www.example.com"
      },
      "transport": {
        "early_data_header_name": "Sec-WebSocket-Protocol",
        "headers": {
          "Host": "www.example.com"
        },
        "max_early_data": 2560,
        "path": "/",
        "type": "ws"
      },
      "type": "vless",
      "uuid": "31c72d79-18fb-495d-8e85-f2b51c7f84e4",
      "multiplex": {
        "enabled": true,
        "protocol": "smux",
        "max_connections": 4,
        "min_streams": 4,
        "padding": true
      }
    },
    {
      "type": "direct",
      "tag": "direct"
    },
    {
      "type": "dns",
      "tag": "dns-out"
    }
  ],
  "route": {
    "auto_detect_interface": true,
    "rules": [
      {
        "type": "logical",
        "mode": "or",
        "rules": [
          {
            "protocol": "dns"
          },
          {
            "port": 53
          }
        ],
        "outbound": "dns-out"
      }
    ]
  }
}

Logs

DEBUG[0001] [1864092512 9ms] dns: lookup domain www.example.com
INFO[0001] outbound/direct[direct]: outbound packet connection to 223.5.5.5:53
INFO[0001] outbound/direct[direct]: outbound packet connection to 223.5.5.5:53
DEBUG[0001] [1864092512 10ms] dns: lookup failed for www.example.com: exchange6: context canceled | exchange4: context canceled | upstream: context canceled

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Integrity requirements

• I confirm that I have read the documentation, understand the meaning of all the configuration items I wrote, and did not pile up seemingly useful options or default values.
• I confirm that I have provided the server and client configuration files and process that can be reproduced locally, instead of a complicated client configuration file that has been stripped of sensitive data.
• I confirm that I have provided the simplest configuration that can be used to reproduce the error I reported, instead of depending on remote servers, TUN, graphical interface clients, or other closed-source software.
• I confirm that I have provided the complete configuration files and logs, rather than just providing parts I think are useful out of confidence in my own intelligence.