[Dovecot] imap-login: memory corruption

[Ralf Hildebrandt]

* Timo Sirainen <tss at iki.fi>:

> How soon after upgrading to 1.1.8 did this happen? 

it always happened, even befor 1.1.8 :)

> There was one login process change done for 1.1.8, but it was supposed
> to fix a crash. And I don't really see how it could cause memory
> corruption. I guess you haven't seen these with older versions?

Yes, I have seen those with older versions.

> > > Do you use SSL?
> > Yes.
> 
> Did you happen to upgrade OpenSSL also?

It's the Debian Package, no.

> > login_process_per_connection = no
> 
> That makes it more difficult to debug. I was thinking about ways to see
> if the crashes happens because one specific user is trying to log in or
> if they're completely different users. Adding %p to
> login_log_format_elements would log PIDs of users that successfully log
> in, but if the crash happens before logging in that doesn't really help
> (and with login_process_per_connection=no it's even more useless).

I tried "login_process_per_connection = yes" but that gives me problems:

Jan 14 16:59:05 postamt dovecot: Dovecot v1.1.8 starting up
Jan 14 16:59:07 postamt dovecot: Fatal: imap-login: epoll_create(): Too many open files
Jan 14 16:59:07 postamt dovecot: Temporary failure in creating login processes, slowing down for now
Jan 14 16:59:07 postamt dovecot: child 17937 (login) returned error 89 (Fatal failure)
Jan 14 16:59:07 postamt dovecot: child 17938 (login) returned error 89 (Fatal failure)
Jan 14 16:59:07 postamt dovecot: Fatal: imap-login: epoll_create(): Too many open files
Jan 14 17:00:07 postamt dovecot: Created login processes successfully, unstalling
Jan 14 17:00:07 postamt dovecot: child 20033 (login) returned error 89 (Fatal failure)
Jan 14 17:00:07 postamt dovecot: child 20037 (login) returned error 89 (Fatal failure)
Jan 14 17:00:07 postamt dovecot: child 20038 (login) returned error 89 (Fatal failure)
Jan 14 17:00:07 postamt dovecot: child 20040 (login) returned error 89 (Fatal failure)
Jan 14 17:00:07 postamt dovecot: child 20041 (login) returned error 89 (Fatal failure)
Jan 14 17:00:07 postamt dovecot: child 20042 (login) returned error 89 (Fatal failure)
Jan 14 17:00:07 postamt dovecot: child 20043 (login) returned error 89 (Fatal failure)
Jan 14 17:00:07 postamt dovecot: child 20044 (login) returned error 89 (Fatal failure)
Jan 14 17:00:07 postamt dovecot: child 20045 (login) returned error 89 (Fatal failure)
Jan 14 17:00:07 postamt dovecot: child 20046 (login) returned error 89 (Fatal failure)
Jan 14 17:00:07 postamt dovecot: child 20047 (login) returned error 89 (Fatal failure)
Jan 14 17:00:07 postamt dovecot: child 20048 (login) returned error 89 (Fatal failure)
Jan 14 17:00:07 postamt dovecot: Fatal: imap-login: epoll_create(): Too many open files
Jan 14 17:00:07 postamt dovecot: Temporary failure in creating login processes, slowing down for now
Jan 14 17:00:07 postamt dovecot: Fatal: imap-login: epoll_create(): Too many open files
Jan 14 17:01:07 postamt dovecot: Created login processes successfully, unstalling
Jan 14 17:01:07 postamt dovecot: child 21758 (login) returned error 89 (Fatal failure)
Jan 14 17:01:07 postamt dovecot: Fatal: imap-login: epoll_create(): Too many open files
Jan 14 17:01:07 postamt dovecot: Temporary failure in creating login processes, slowing down for now
Jan 14 17:01:07 postamt dovecot: Fatal: imap-login: epoll_create(): Too many open files
Jan 14 17:01:07 postamt dovecot: child 21757 (login) returned error 89 (Fatal failure)
Jan 14 17:01:07 postamt dovecot: Fatal: imap-login: epoll_create(): Too many open files

> I was also thinking about adding some code that would attach IP address
> to the "killed with signal n" error (with
> login_process_per_connection=no it would be the last IP that started
> logging in).



-- 
Ralf Hildebrandt (Ralf.Hildebrandt at charite.de)          snickebo at charite.de
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