Checklist

• 1. I have searched related issues but cannot get the expected help.
• 2. The bug has not been fixed in the latest version.
• 3. Please note that if the bug-related issue you submitted lacks corresponding environment info and a minimal reproducible demo, it will be challenging for us to reproduce and resolve the issue, reducing the likelihood of receiving feedback.
• 4. If the issue you raised is not a bug but a question, please raise a discussion at https://github.com/sgl-project/sglang/discussions/new/choose Otherwise, it will be closed.
• 5. Please use English, otherwise it will be closed.

Describe the bug

When my request body is illegal json, it directly returns a 500 error, not a JSON structure.

root@kebe-dev:~# curl 127.0.0.1:30000/v1/chat/completions  -H "Content-Type: application/json"     -d '{"model": "model", "messages": [{"role": "user", "content": "13x^2 + 5x - 102 = 0, x = ? "}],"temperature": 0.7, "stream": true, x}'  // x is invalid
Internal Server Error

Reproduction

root@kebe-dev:~# curl 127.0.0.1:30000/v1/chat/completions  -H "Content-Type: application/json"     -d '{"model": "model", "messages": [{"role": "user", "content": "13x^2 + 5x - 102 = 0, x = ? "}],"temperature": 0.7, "stream": true, x}'  // x is invalid
Internal Server Error

Environment

N/A