Fatal Error after upgrade to 2:2.3.19-2+debian11

[Timo Sirainen]

On 16. May 2022, at 14.09, Sebastian Kroczek <skroczek at wavecon.de> wrote:
> 
> Hello all,
> 
> I updated the server tonight and with it Dovecot from 2.2.27 to 2:2.3.19-2+debian11. However, there seems to be a problem with the ACLs, because since then fatal errors are logged (see core dump). I suspect that some outdated configuration is causing this behavior, but so far I couldn't figure out which one it could be. I also have no clue right now how to debug this further.
> Thank you very much for your help. If more information are needed, I will of course be happy to provide them.
..
>                #0  0x00007f5db938c17c acl_mailbox_get_aclobj (lib01_acl_plugin.so + 0xf17c)
>                #1  0x00007f5db93776ed n/a (lib02_imap_acl_plugin.so + 0x36ed)

It looks like one of the IMAP ACL commands causes the crash, but other than that this isn't enough information and I can't easily reproduce. Can you install dovecot-dbg package and see if you can get a gdb backtrace? :

gdb /usr/lib/dovecot/imap /path/to/core
bt full