Panic: file smtp-client-connection.c: line 1142 (smtp_client_connection_established)

[Stephan Bosch]

On 19/11/2019 13:25, Dirk via dovecot wrote:
> I'm using dovecot in a multi server setup. Two directors forward pop3, 
> imap and smtp to  backend dovecots with their central storage on NFS.
> Yesterday I stumbled upon these log lines:
>
> 2019-11-18 20:17:51 lmtp(17274): Info: Connect from 172.22.1.6
> 2019-11-18 20:17:51 lmtp(17274): Panic: file smtp-client-connection.c: 
> line 1142 (smtp_client_connection_established): assertion failed: 
> (!conn->connect_succeeded)
> 2019-11-18 20:17:51 lmtp(17274): Fatal: master: service(lmtp): child 
> 17274 killed with signal 6 (core not dumped - 
> https://dovecot.org/bugreport.html#coredumps - set 
> /proc/sys/fs/suid_dumpable to 2)
>
> Is a core dump required to find the source of that error?
>

This bug is known (DOV-3600), fixed and currently scheduled for release 
in 2.3.10.

Regards,

Stephan.

> Thanks for any help!
>
>
> $ doveconf -n
> # 2.3.4.1 (f79e8e7e4): /etc/dovecot/dovecot.conf
> # OS: Linux 4.9.0-8-amd64 x86_64
> # Hostname: m03.company.com <http://m03.company.com>
> auth_cache_negative_ttl = 65 secs
> auth_cache_ttl = 3 mins
> auth_cache_verify_password_with_worker = yes
> auth_mechanisms = plain login
> auth_verbose = yes
> debug_log_path = /dev/stdout
> default_client_limit = 10400
> default_process_limit = 1024
> default_vsz_limit = 1 G
> deliver_log_format = msgid=%m: %s %{session_time} %$
> director_mail_servers = 10.10.10.2 10.10.10.3
> director_servers = 10.10.1.2 10.10.1.3
> imap_id_log = *
> imap_max_line_length = 2 M
> import_environment = TZ CORE_OUTOFMEM CORE_ERROR
> info_log_path = /dev/stdout
> instance_name = dovecot_director
> listen = 10.10.1.3,::
> lmtp_proxy = yes
> log_path = /dev/stderr
> log_timestamp = "%Y-%m-%d %H:%M:%S "
> login_log_format_elements = user=<%u> method=%m rip=%r lip=%l mpid=%e 
> %c %k session=<%{session}>
> mail_max_userip_connections = 250
> passdb {
>   args = /etc/dovecot/sql/dovecot-dict-sql-passdb.conf
>   driver = sql
>   result_failure = return-fail
>   result_internalfail = return-fail
>   result_success = continue-ok
> }
> passdb {
>   args = proxy=y starttls=any-cert master=director at m03.company.com 
> <mailto:master=director at m03.company.com> pass=#hidden_use-P_to_show# 
> nopassword=y
>   driver = static
>   skip = unauthenticated
> }
> pop3_logout_format = top=%t/%p, retr=%r/%b, del=%d/%m, size=%s, uidl=%u
> protocols = imap lmtp pop3
> service auth-worker {
>   user = $default_internal_user
> }
> service director {
>   fifo_listener login/proxy-notify {
>     mode = 0600
>     user = $default_login_user
>   }
>   inet_listener {
>     port = 9090
>   }
>   unix_listener director-userdb {
>     mode = 0600
>     user = vmail
>   }
>   unix_listener login/director {
>     mode = 0666
>   }
> }
> service imap-login {
>   executable = imap-login director
>   process_min_avail = 2
>   vsz_limit = 1 G
> }
> service lmtp {
>   inet_listener lmtp {
>     port = 24
>   }
>   process_min_avail = 2
>   unix_listener lmtp {
>     mode = 00
>   }
>   user = vmail
>   vsz_limit = 1 G
> }
> service log {
>   user = dovenull
> }
> service pop3-login {
>   executable = pop3-login director
>   process_min_avail = 2
>   vsz_limit = 1 G
> }
> service pop3 {
>   user = vmail
> }
> ssl_cert = </etc/ssl/mail/cert.pem
> ssl_client_ca_dir = /etc/ssl/certs/
> ssl_dh = # hidden, use -P to show it
> ssl_key = # hidden, use -P to show it
> ssl_prefer_server_ciphers = yes
> submission_host = postfix:588
> protocol lmtp {
>   auth_socket_path = director-userdb
> }