[Dovecot] crash on shared folders if remote user has empty $home

[Peer Heinlein]

Hi,

in seldom cirumstances it's possible that the imap-process is crashing 
without write something usefule into the logfile.

a) User foo exists, is happy and everything's alright

b) He had a shared folder given from bar

c) In our setup we have mailforwarding adresses without a valid $home in 
LDAP

c) if user bar is changed from a user with into a mailforwarding adress, 
the user foo won't have an entry for $home any more, but still exists in 
LDAP.

d) If foo logs in, dovecot's exploring the shared folders given from the 
non-existing user bar. But bar's entry in LDAP doesn't have $home any 
more. imap crashes and closes the TCP-connection immediately.

root at dobby2:/etc/dovecot# telnet xxxxxxxx 143
Escape character is '^]'.
* OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE 
IDLE ACL UIDPLUS STARTTLS AUTH=PLAIN AUTH=LOGIN AUTH=CRAM-MD5 
AUTH=DIGEST-MD5] Dovecot ready. Testing.
a LOGIN foo xxxxx
a OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE 
IDLE SORT SORT=DISPLAY THREAD=REFERENCES THREAD=REFS MULTIAPPEND 
UNSELECT CHILDREN NAMESPACE UIDPLUS LIST-EXTENDED I18NLEVEL=1 CONDSTORE 
QRESYNC ESEARCH ESORT SEARCHRES WITHIN CONTEXT=SEARCH LIST-STATUS ACL 
UIDPLUS QUOTA ACL RIGHTS=texk] Logged in
a LIST "" "*"
* BYE Internal error occurred. Refer to server log for more information.
Connection closed by foreign host.

Dec 22 21:57:41 dobby2 dovecot: master: Error: service(imap): child 
18095 killed with signal 11 (core dumps disabled)


e) This happens if mail_location=mdbox:%%h/mdbox is set in the shared 
folder namespace. If I set "mail_location=auto:" then Dovecot logs an 
error message, but is still possible to continue without any problems.

Dec 22 21:33:59 dobby2 dovecot: imap(bar): Error: Namespace 
'shared/bar/': Autodetection failed for auto: (home=/mail/foo/)

-- 

Heinlein Professional Linux Support GmbH
Linux: Akademie - Support - Hosting

http://www.heinlein-support.de
Tel: 030 / 40 50 51 - 0
Fax: 030 / 40 50 51 - 19

Zwangsangaben lt. §35a GmbHG:
HRB 93818 B / Amtsgericht Berlin-Charlottenburg,
Geschäftsführer: Peer Heinlein  -- Sitz: Berlin