Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

Create a user with a password:
create user u1 identified with 'caching_sha2_password' by '123456';

Then connect to TiDB with mysql client without a password:
mysql -h127.1 -uu1 -P4000

2. What did you expect to see? (Required)

mysql -h127.1 -uu1 -P3306
ERROR 1045 (28000): Access denied for user 'u1'@'localhost' (using password: NO)

3. What did you see instead (Required)

mysql -h127.1 -uu1 -P4000
ERROR 2027 (HY000): Malformed packet

4. What is your TiDB version? (Required)

master

mysql --version
mysql  Ver 8.0.29 for macos12.2 on x86_64 (Homebrew)