The bug happens not very often, it might need a week to get a core file. 


Il giorno ven 21 dic 2018 alle ore 15:18 Aki Tuomi <aki.tuomi@open-xchange.com> ha scritto:

On 21.12.2018 14.49, Giacomo wrote:
> I'm running the following:
>
> # 2.3.4 (0ecbaf23d): /usr/local/etc/dovecot/dovecot.conf
> # OS: FreeBSD 11.2-RELEASE-p4 amd64  
> # FS: ZFS
>
> auth_mechanisms = plain login
> auth_username_format = %Ln
> listen = *
> mail_location = maildir:~/Maildir
> namespace inbox {
>   inbox = yes
>   location = 
>   mailbox Drafts {
>     auto = subscribe
>     special_use = \Drafts
>   }
>   mailbox Junk {
>     auto = subscribe
>     special_use = \Junk
>   }
>   mailbox Sent {
>     special_use = \Sent
>   }
>   mailbox Trash {
>     auto = subscribe
>     special_use = \Trash
>   }
>   prefix = 
> }
> passdb {
>   driver = pam
> }
> protocols = imap lmtp
> service auth {
>   unix_listener /var/spool/postfix/private/auth {
>     group = postfix
>     mode = 0666
>     user = postfix
>   }
>   user = dovecot
> }
> service imap-login {
>   inet_listener imap {
>     port = 0
>   }
> }
> service lmtp {
>   unix_listener /var/spool/postfix/private/dovecot-lmtp {
>     group = postfix
>     mode = 0600
>     user = postfix
>   }
> }
> service stats {
>   unix_listener stats-reader {
>     group = 
>     mode = 0600
>     user = 
>   }
>   unix_listener stats-writer {
>     group = $default_internal_group
>     mode = 0666
>     user = 
>   }
>   user = $default_internal_user
> }
> ssl_cert = </root/cert.pem
> ssl_key = # hidden, use -P to show it
> userdb {
>   driver = passwd
> }
>
> dmesg shows:
>
> pid 74441 (imap), uid 1002: exited on signal 6
> pid 74784 (imap), uid 1002: exited on signal 6
> pid 21471 (imap), uid 1002: exited on signal 6
> pid 21470 (imap), uid 1002: exited on signal 6
> pid 21464 (imap), uid 1002: exited on signal 6
> pid 21731 (imap), uid 1002: exited on signal 6
>
> Sometimes the dovecot process serving an user crashes. He runs mostly
> airmail on macOS and samsung mail on Android.
>
> Happens only to that particular user.
>
> The log shows the following: (maillog)
>
> Dec 16 14:52:35 mail dovecot: imap-login: Login: user=<USER>,
> method=PLAIN, rip=79.12.201.157, lip=192.168.1.28, mpid=74779, TLS,
> session=<wMQI+iN9VtRPDMmd>
> Dec 16 14:52:39 mail dovecot: imap(USER)<74441><nLa+7SN9+fhPDMmd>:
> Panic: file charset-iconv.c: line 83 (charset_to_utf8_try): assertion
> failed: (srcleft <= CHARSET_MAX_PENDING_BUF_SIZE)
> Dec 16 14:52:39 mail dovecot: imap(USER)<74441><nLa+7SN9+fhPDMmd>:
> Fatal: master: service(imap): child 74441 killed with signal 6 (core
> not dumped - https://dovecot.org/bugreport.html#coredumps - set
> service imap { drop_priv_before_exec=yes })
>
> I'm here if more info is needed.
>
> Thanks for taking a look.


Can you somehow get a core file and get backtrace from it?


Aki