Crash on opening mailbox

[Aki Tuomi]

> On August 19, 2016 at 10:00 PM Ladislav Laska <laska at kam.mff.cuni.cz> wrote:
> 
> 
> Hi! 
> 
> I'm currently experiencing a crash of dovecot 2.2.25 on Gentoo, upon opening 
> mailbox. The crash only triggers on opening inbox, other mailboxes seem to work 
> fine. It happens every time, and can be reproduced on request. I also briefly 
> tried 2.2.19, and it behaves the same.
> 
> The bug seems to be triggered by some mail, as I encountered it previously and 
> fixed by removing some spam. I guess it might be malformed header of some kind.  
> I can open the mailbox locally using mutt, but fail to do so remotely (using 
> mutt or K-9 mail on android). Unforunately, I haven't been able to isolate the 
> specific mail, as when I create a new mailbox, dovecot refuses to open it:
> 
> [CANNOT] Mailbox isn't a valid mbox file (0.000 + 0.000 secs).
> 
> I'm not really sure what's going on and will investigate further once I find 
> some time to do so.
> 
> I also experienced a similar problem on opening a specific mail, but it's much 
> harder to reproduce and I currently don't have an example. The crash looks very 
> similar, and only happens on first attempt to open a specific mail, it always 
> works later on.
> 
> I'm attaching a stack trace and dovecot -n. I'm also willing to send the binary 
> and core dump, but not publicly, as I'm not eager to share whatever's inside 
> with the whole world.
> 
> Other than what I mentioned, I'm running pretty standard setup, with postfix on 
> Gentoo x86_64, ext4 fs, quota and disk space is plentiful. The delivery agent is 
> dovecot itself, in postfix/main.cf I have:
> 
> mailbox_command = /usr/libexec/dovecot/deliver
> 
> I'm using sieve script to file my mail, but the problem manifested even before 
> when I was still using procmail to deliver my mail (I migrated because I had 
> doubts about procmail and dovecot lock cooperation)
> 
> I'll keep my mailbox corrupted for a few more days, and access the mail only 
> locally, hoping to test a potential fix. Let me know if you need any more 
> info/experimentation. Also, if you know a good way to find the mail that causes 
> the trouble out of the core, let me know, I'd be glad to forward it for testing.
> 
> Thanks and I hope we can find (and fix) the problem!
> 
> -- 
> S pozdravem Ladislav Láska                          <laska at kam.mff.cuni.cz>
> Katedra Aplikované Matematiky, MFF UK               tel.: +420 739 464 167

Hi!

Please provide

doveconf -n

relevant log files (or at least anything you care to share)

gdb /path/to/binary /path/to/core
bt full

---
Aki Tuomi
Dovecot Oy