sshd Failed password

I see a log of Failed password attempt from sshd logs:

cat /var/log/auth.log | grep 'Failed password'

The ip involved are:

181.63.251.33
43.229.53.61
92.222.252.202
117.121.7.103
95.72.95.225
115.231.98.109
222.241.151.149
62.210.27.83
104.238.95.141
95.72.194.114
62.210.27.83
27.254.96.92
222.42.146.175
24.172.189.104
211.245.169.201
192.3.6.154
159.203.85.184
36.84.248.8
95.72.95.141
80.77.159.246
114.207.113.183
201.90.216.10
43.229.53.60
112.33.2.47
61.153.144.5
158.69.206.217
123.63.0.157
220.225.7.31
182.74.247.202
117.253.215.253
62.210.6.59
194.84.2.90
182.73.13.154
189.112.216.136
31.173.68.107
85.172.11.138
222.186.21.33
62.210.6.59
195.154.39.163

All blocked!

for IP in $(cat ip_list); do iptables -A INPUT -s $IP -j DROP; done

Bug for details: https://janzhou.org/bugzilla/show_bug.cgi?id=13