On 27. Aug 2025, at 12.30, pelzi--- via dovecot <dovecot@dovecot.org> wrote:
Found out what triggers the crashes: it is *not* the lexicographically lowest someotheruser, it is a someotheruser with a group acl active on its INBOX. If you manually remove the group acl from the affected mailbox's acl file, access is possible as granted to users in the remaining acl lines.
This can be tested just by dovecot acl debug - it crashes the same way as the imap process and is much easier to debug. To provoke crashing, just issue something like:
$ doveadm acl add -u someuser shared/someotheruser/INBOX group=somegroup lookup
This command will try to rmdir someotheruser's inbox file, then crash, plus any subsequent calls like
I can reproduce the crash, but not the rmdir() error. Not really sure where it's coming from. Can you get a gdb backtrace to it as well? Maybe:
gdb --args doveadm acl add -u someuser shared/someotheruser/INBOX group=somegroup lookup b rmdir run
Or if that doesn't work for some reason, you should be able to get a core dump from all errors with:
log_core_filter = category=error