Kernel panic in dovecot-ee-lmtp on Debian 8

[Michael Slusarz]

Fixed -- Publicly accessible link to commit:

https://github.com/dovecot/pigeonhole/commit/a95b0579b89c13fb3ee5700e76cbe6a4a3e898e0


> On April 25, 2016 at 10:46 AM Stephan Bosch <stephan at rename-it.nl> wrote:
> 
> 
> 
> 
> Op 25-4-2016 om 18:01 schreef Timo Sirainen:
> > On 25 Apr 2016, at 13:48, Tobi <tobster at brain-force.ch> wrote:
> >> Hi list
> >>
> >> I just realized that that I don not receive all mails in my mailbox
> >> (running dovecot-ee 2.2.23.1-1 on Debian 8). On my frontend servers
> >> (running postfix) the queue fills up with mails that cannot be delivered
> >> via lmtp to my backend servers. The error message on the frontend is
> >> "lost connection with backend while sending data"
> >> When I checked the logs on the backend server I found upon every
> >> delivery attempt kernel panics
> >>
> >> Apr 25 12:33:36 mbox1 dovecot: lmtp(REDACTED): Panic: epoll_ctl(del, 18)
> >> failed: Bad file descriptor
> >> Apr 25 12:33:36 mbox1 dovecot: lmtp(REDACTED): Error: Raw backtrace:
> > Can you get a core dump and gdb backtrace? See http://dovecot.org/bugreport.html#coredumps
> >
> >> /usr/lib/dovecot/libdovecot-sieve.so.0(program_client_run+0xe8)
> >> [0x7faa17d3b308] ->
> >> /usr/lib/dovecot/modules/sieve/lib90_sieve_extprograms_plugin.so(+0x45b8) [0x7faa15d855b8]
> >> ->
> >> /usr/lib/dovecot/libdovecot-sieve.so.0(sieve_interpreter_continue+0x7c)
> >> [0x7faa17cfa2ac] ->
> >>
> >> the weird thing is that this is not concerning all incoming mails. From
> >> time to time the frontends can deliver messages to my backends. I just
> >> tested it with a mail from work. It arrived via a frontend that has
> >> other mails in queue that could not be delivered so far.
> >>
> >> Does anyone have an idea where I could look for the root cause of this
> >> panic messages?
> > Looks like somehow caused by sieve extprograms.
> 
> Probably this bug:
> 
> https://git.dovecot.net/pigeonhole/core/commit/a95b0579b89c13fb3ee5700e76cbe6a4a3e898e0
> 
> Fixed for upcoming release.
> 
> Regards,
> 
> Stephan.