segfault at [..] error 4 in libmariadb.so

May 13 21:23:06 xoxoxoxo kernel: [190672.236709] python3[19610]: segfault at 7fb0a802101e ip 00007fb0b7c85487 sp 00007fb0b59173e0 error 4 in libmariadb.so.3[7fb0b7c74000+23000]

May 13 21:23:06 xoxoxoxo kernel: [190672.241290] Code: 70 48 85 c0 0f 84 2b ff ff ff 8b 53 64 85 d2 0f 84 20 ff ff ff 31 c9 31 d2 eb 0c 0f 1f 84 00 00 00 00 00 48 8b 43 70 48 01 c8 <80> 78 66 00 74 04 c6 40 66 00 8b 43 64 48 83 c2 01 48 83 c1 70 48

#!/usr/bin/env python3

# pymilter  1.0.3

# mariadb   0.9.58

import Milter

import mariadb

MAIL_RATE_DB = 'mail_rate_statistics'

MAIL_RATE_TBL = 'mail_counter'

def main():

    dbconn = initialize_database()

    socketname = "/var/run/milters/mail_rate_milter.sock"

    timeout = 300

    Milter.factory = MailRateMilter

    Milter.factory.dbconn = dbconn

    Milter.set_exception_policy(Milter.CONTINUE)

    Milter.runmilter("mail_rate_milter", socketname, timeout)

def initialize_database():

    dbconn = mariadb.connect(host='localhost', database='{}'.format(MAIL_RATE_DB))

    dbconn.auto_reconnect = True

    return dbconn

class MailRateMilter(Milter.Base):

    def __init__(self):

        self.id = Milter.uniqueID()

        self.server = str()

    @Milter.noreply

    def hello(self, hostname):

        self.server = hostname

        return Milter.CONTINUE

    @Milter.noreply

    def envfrom(self, f, *str):

        self.add_addr_to_rate_db(f)

        return Milter.ACCEPT

    def add_addr_to_rate_db(self, mail_from):

        self.dbconn.ping()

        account = mail_from.strip('<>').partition('@')[0]

        domain = mail_from.strip('<>').partition('@')[2]

        dbcurs = self.dbconn.cursor()

        sql = "INSERT INTO {} VALUES (CURRENT_TIMESTAMP(3), ?, ?, ?, ?)".format(MAIL_RATE_TBL)

        dbcurs.execute(sql, (mail_from.strip('<>'), account, domain, self.server))

if __name__=="__main__":

    main()