Bug#855326: courier-imap: INTERNAL ERROR: Keyword hashtable memory corruption.

["Ralf G. R. Bergs" <Ralf+Debian@Bergs.biz>]

Package: courier-imap
Version: 4.15-1.6
Severity: normal

Dear Maintainer,

I noticed the following message in syslog:

imapd: <email-addr>: INTERNAL ERROR: Keyword hashtable memory
corruption.

I cannot recall to ever have seen this message, even though I scan my
logs on a daily basis for unusual events.

An internet search didn't turn up any meaningful explanation for this
event.

Please let me know how I can help tracking this down.

Kr,

Ralf

-- System Information:
Debian Release: 8.7
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 3.16.0-4-amd64 (SMP w/8 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: sysvinit (via /sbin/init)

Versions of packages courier-imap depends on:
ii  courier-authlib                            0.66.1-1+b1
ii  courier-base                               0.73.1-1.6
ii  debconf                                    1.5.56
ii  exim4-daemon-heavy [mail-transport-agent]  4.84.2-2+deb8u3
ii  libc6                                      2.19-18+deb8u7
ii  libgamin0 [libfam0]                        0.1.10-4.1
ii  libgdbm3                                   1.8.3-13.1

courier-imap recommends no packages.

Versions of packages courier-imap suggests:
pn  courier-doc         <none>
ii  courier-imap-ssl    4.15-1.6
ii  mutt [imap-client]  1.5.23-3

-- Configuration Files:
/etc/courier/imapd changed:
ADDRESS=0
PORT=143
MAXDAEMONS=150
MAXPERIP=40
PIDFILE=/var/run/courier/imapd.pid
TCPDOPTS="-nodnslookup -noidentlookup"
LOGGEROPTS="-name=imapd"
IMAP_CAPABILITY="IMAP4rev1 UIDPLUS CHILDREN NAMESPACE THREAD=ORDEREDSUBJECT THREAD=REFERENCES SORT QUOTA AUTH=CRAM-MD5 AUTH=CRAM-SHA1 AUTH=CRAM-SHA256 IDLE"
IMAP_KEYWORDS=1
IMAP_ACL=1
IMAP_CAPABILITY_ORIG="IMAP4rev1 UIDPLUS CHILDREN NAMESPACE THREAD=ORDEREDSUBJECT THREAD=REFERENCES SORT QUOTA AUTH=CRAM-MD5 AUTH=CRAM-SHA1 AUTH=CRAM-SHA256 IDLE"
IMAP_PROXY=0
IMAP_PROXY_FOREIGN=0
IMAP_IDLE_TIMEOUT=60
IMAP_MAILBOX_SANITY_CHECK=0
IMAP_CAPABILITY_TLS="$IMAP_CAPABILITY AUTH=PLAIN"
IMAP_CAPABILITY_TLS_ORIG="$IMAP_CAPABILITY_ORIG AUTH=PLAIN"
IMAP_DISABLETHREADSORT=0
IMAP_CHECK_ALL_FOLDERS=1
IMAP_OBSOLETE_CLIENT=0
IMAP_UMASK=022
IMAP_ULIMITD=131072
IMAP_USELOCKS=1
IMAP_ENHANCEDIDLE=1
IMAP_TRASHFOLDERNAME=Trash
IMAP_EMPTYTRASH=Trash:7
IMAP_MOVE_EXPUNGE_TO_TRASH=0
SENDMAIL=/usr/sbin/sendmail
HEADERFROM=X-IMAP-Sender
IMAP_ID_FIELDS=0
OUTBOX_MULTIPLE_SEND=1
IMAPDSTART=YES
MAILDIRPATH=Maildir

/etc/logcheck/ignore.d.server/courier-imap [Errno 13] Permission denied: u'/etc/logcheck/ignore.d.server/courier-imap'
/etc/logcheck/violations.ignore.d/courier-imap [Errno 13] Permission denied: u'/etc/logcheck/violations.ignore.d/courier-imap'

-- no debconf information