I've just enabled core dumps on the involved FreeBSD system. Let's see if it dumps something..

Il giorno dom 20 gen 2019 alle ore 19:16 Stephan Bosch <stephan@rename-it.nl> ha scritto:
Hi Giacomo,

Op 21/12/2018 om 16:16 schreef Giacomo:
> The bug happens not very often, it might need a week to get a core file.

Any luck getting a core file?

Regards,

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