Comment 9 for bug 997217

I'm sorry to say, that there is no simple test case.

The problem cannot be reproduced with simple instructions. You need to run saslauthd -a rimap for a few days in front of nginx-extras+dovecot IMAP and do a lot of imap logins to trigger the bug. But the bug is already fixed by the newer patch version of 0034-fix_dovecot_authentication.patch in 2.1.25.dfsg1-17.

Some more system information:

Precise nginx:

mail01:~# dpkg -l "nginx*" |grep ^ii
ii nginx-common 1.1.19-1ubuntu0.4 small, but very powerful and efficient web server (common files)
ii nginx-extras 1.1.19-1ubuntu0.4 nginx web server with full set of core modules and extras

Self-compiled known-to-be-working stable dovecot release 2.1.16:

mail01:~# doveconf -n |head -2
# 2.1.16: /etc/dovecot/dovecot.conf
# OS: Linux 3.2.0-56-generic x86_64 Ubuntu 12.04.3 LTS

Saslauthd ist running with following parameters, where 10.10.10.10 is the remote dovecot imap server:

/usr/sbin/saslauthd -a rimap -O 10.10.10.10 -r -c -t 60 -m /var/run/saslauthd -n 5

In the meanwhile I took 0034-fix_dovecot_authentication.patch from the saucy package https://launchpad.net/ubuntu/saucy/amd64/sasl2-bin/2.1.25.dfsg1-17, updated the patch
0034-fix_dovecot_authentication.patch in the precise package and installed it on our servers.

I'll run for a few days (or weeks) now, and see if the CPU problem goes away.

If you want to test an official package update for precise, we can do so on one of the machines.

Regards
Daniel