doveadm: Error: open(/proc/self/io) failed

[Sami Ketola]

> On 30 Jul 2019, at 22.53, Tom Diehl via dovecot <dovecot at dovecot.org> wrote:
> 
> On Tue, 30 Jul 2019, Reio Remma via dovecot wrote:
> 
>> On 30.07.2019 20:07, Tom Diehl via dovecot wrote:
>>> 
>>> Does anyone have an Idea how to fix this?
>> 
>> Perhaps see if there are any denials in SELinux audit log:
> 
> Selinux is in permissive.
> 
> If I do:
> (vmail1 pts9) # ll /proc/self/io -r-------- 1 root root 0 Jul 30 15:27 /proc/self/io
> (vmail1 pts9) #
> 
> It is obvious to me why I get permission denied. The problem is you
> cannot chmod on /proc. I suspect I have something mis-configured but
> the question is what?

service lmtp {
 executable = lmtp -L
 inet_listener lmtp {
   address = 127.0.0.1
   port = 24
 }
 process_min_avail = 5
 unix_listener /var/spool/postfix/private/dovecot-lmtp {
   group = postfix
   mode = 0600
   user = postfix
 }
 user = vmail
}

please remove user = vmail from here or change it to root.

for security reasons lmtp service must be started as root since version 2.2.36. lmtp will drop root privileges after initialisation but it needs to open /self/proc/io as root before that.

Sami