Hello,

We’re running a cluster of dovecot servers for a large amount of users. It’s been working pretty well except we are seeing occasional fatal error messages.

Here is a sample error message that we are seeing: Nov 20 19:51:29 ip-10-238-11-11 dovecot: imap(): Fatal: master: service(imap): child 796 killed with signal 11 (core dumped)

We are running dovecot 2.2.9 installed from apt-get on Ubuntu 14.04.

I’ve checked out the core dump and here is the stack trace:

Core was generated by `dovecot/imap [e22a36135b5f40'. Program terminated with signal SIGSEGV, Segmentation fault. #0 0x00007f83d63aa757 in mail_transaction_log_view_mark (view=0x7f83d804f8c0) at mail-transaction-log-view.c:794 794 mail-transaction-log-view.c: No such file or directory. (gdb) bt #0 0x00007f83d63aa757 in mail_transaction_log_view_mark (view=0x7f83d804f8c0) at mail-transaction-log-view.c:794 #1 0x00007f83d63a3796 in view_sync_have_expunges (view=0x7f83d804f7e0) at mail-index-view-sync.c:223 #2 mail_index_view_sync_begin (view=0x7f83d804f7e0, flags=flags@entry=MAIL_INDEX_VIEW_SYNC_FLAG_NOEXPUNGES) at mail-index-view-sync.c:583 #3 0x00007f83d6382168 in index_mailbox_sync_init (box=box@entry=0x7f83d8049f80, flags=flags@entry=(MAILBOX_SYNC_FLAG_FAST | MAILBOX_SYNC_FLAG_NO_EXPUNGES), failed=<optimized out>) at index-sync.c:226 #4 0x00007f83d632983b in maildir_storage_sync_init (box=0x7f83d8049f80, flags=(MAILBOX_SYNC_FLAG_FAST | MAILBOX_SYNC_FLAG_NO_EXPUNGES)) at maildir-sync.c:1120 #5 0x00007f83d6356cf9 in mailbox_sync_init (box=box@entry=0x7f83d8049f80, flags=flags@entry=(MAILBOX_SYNC_FLAG_FAST | MAILBOX_SYNC_FLAG_NO_EXPUNGES)) at mail-storage.c:1668 #6 0x00007f83d6835e5e in imap_sync_init (client=client@entry=0x7f83d8046b60, box=<optimized out>, imap_flags=(unknown: 0), flags=(MAILBOX_SYNC_FLAG_FAST | MAILBOX_SYNC_FLAG_NO_EXPUNGES)) at imap-sync.c:230 #7 0x00007f83d6836af0 in cmd_sync_client (sync_cmd=0x7f83d8047760) at imap-sync.c:739 #8 cmd_sync_delayed_real (client=0x7f83d8046b60) at imap-sync.c:877 #9 cmd_sync_delayed (client=client@entry=0x7f83d8046b60) at imap-sync.c:885 #10 0x00007f83d682db61 in client_handle_input (client=client@entry=0x7f83d8046b60) at imap-client.c:906 #11 0x00007f83d682de35 in client_input (client=0x7f83d8046b60) at imap-client.c:933 #12 0x00007f83d608c247 in io_loop_call_io (io=0x7f83d8047660) at ioloop.c:388 #13 0x00007f83d608cfd7 in io_loop_handler_run (ioloop=ioloop@entry=0x7f83d8030760) at ioloop-epoll.c:220 #14 0x00007f83d608bde8 in io_loop_run (ioloop=0x7f83d8030760) at ioloop.c:412 #15 0x00007f83d603cc93 in master_service_run (service=0x7f83d80305f0, callback=<optimized out>) at master-service.c:566 #16 0x00007f83d68222f4 in main (argc=2, argv=0x7f83d8030390) at main.c:400

Here are the settings we’re running (I’ve removed our domain and path information):

# 2.2.9: /etc/dovecot/dovecot.conf # OS: Linux 3.13.0-24-generic x86_64 Ubuntu 14.04.1 LTS auth_mechanisms = plain login base_dir = /var/run/dovecot/ default_client_limit = 1024 default_process_limit = 256 default_vsz_limit = 1 G disable_plaintext_auth = no mail_privileged_group = mail namespace inbox { inbox = yes location = mailbox Drafts { special_use = \Drafts } mailbox Junk { special_use = \Junk } mailbox Sent { special_use = \Sent } mailbox "Sent Messages" { special_use = \Sent } mailbox Trash { special_use = \Trash } prefix = } passdb { args = /etc/dovecot/dovecot-sql.conf driver = sql } protocols = " imap lmtp pop3" service auth { unix_listener /var/spool/postfix/private/auth { group = postfix mode = 0666 user = postfix } } service imap-login { inet_listener imap { port = 143 } process_min_avail = 4 service_count = 0 vsz_limit = 128 M } service imap-postlogin { executable = script-login /real/location/to/the/script.sh user = vmail } service imap { client_limit = 1 executable = imap imap-postlogin process_limit = 65536 } service lmtp { unix_listener /var/spool/postfix/private/dovecot-lmtp { group = postfix mode = 0600 user = postfix } } service pop3-login { inet_listener pop3 { port = 110 } service_count = 0 } ssl = no userdb { args = /etc/dovecot/dovecot-sql.conf driver = sql } verbose_proctitle = yes protocol lmtp { hostname = real.domain.here postmaster_address = postmaster@real.domain.here }

This seems like some sort of bug within dovecot since we’re seeing a seg fault, but any help would be appreciated. Thanks!