Hello,
I've been trying to set up dovecot to support passwd-file + passwd/PAM auth.
I made an unusual config (passwd-file as userdb failed to work for me), which
uses static as userdb:
===============
passdb {
driver = passwd-file
args = username_format=%u scheme=CRYPT /etc/dovecot/users
}
userdb {
driver = static
default_fields = uid=vmail gid=vmail home=/var/spool/mail/%d/%n
}
passdb {
driver = pam
}
userdb {
driver = passwd
}
===============
While passwd-file+static worked well, passwd/PAM caused trouble:
$ doveadm user xxx
doveadm(root): Error: userdb lookup(xxx): Disconnected unexpectedly
field value
If passwd-file had the user, check went fine; otherwise it segfaulted.
The crash has been accompanied by a syslog message:
kernel: auth[9788]: segfault at 18 ip 0000000000416391 sp 00007fffd11a3d90
error 4 in auth[400000+44000]
Translating address lead me to:
0000000000416390 :
416390: 53 push %rbx
416391: 48 83 7f 18 00 cmpq $0x0,0x18(%rdi)
I was using packages from http://packages.atrpms.net/dist/el6/dovecot/
To be precise, dovecot-2.2.10-1_14.el6.x86_64.rpm
I tampered with the src.rpm, upgraded spec&sources to match 2.2.12.
It didn't help, so I tries to "workaround" this.
The bug has gone when in src/auth/auth-fields.c:210 I added check if the field
ptr is not null. As it's a userdb query, it seems that for some reason
(static?) in src/auth/auth-request.c:1058 the function auth_fields_rollback is
called with null request->userdb_reply
Now it works fine:
$ doveadm user xxx
field value
uid 1000
gid 100
home /home/xxx
mail maildir:~/.maildir
system_groups_user xxx
$ doveadm user jkonczak@ast...
field value
uid 103
gid 103
home /var/spool/mail/ast.../jkonczak
mail maildir:~/.maildir
So now virtual users get vmail uid/gid, system users get their uid/gid, home
is fine etc.
Below I attach the patch + full config.
Regards,
Jan Kończak
===============================================
$ cat SOURCES/dovecot-2.2.12-auth_fields_rollback-nullptr_check.patch
--- src/auth/auth-fields.c.orig 2014-05-11 16:17:49.755258666 +0200
+++ src/auth/auth-fields.c 2014-05-11 16:18:24.704946586 +0200
@@ -207,6 +207,7 @@
void auth_fields_rollback(struct auth_fields *fields)
{
+ if (fields==NULL) return;
if (array_is_created(&fields->snapshot_fields)) {
array_clear(&fields->fields);
array_append_array(&fields->fields, &fields->snapshot_fields);
===============================================
$ dovecot --version
2.2.12
$ doveconf # passdb/userdb/auth related
passdb {
args = username_format=%u scheme=CRYPT /etc/dovecot/users
default_fields =
deny = no
driver = passwd-file
master = no
override_fields =
pass = no
result_failure = continue
result_internalfail = continue
result_success = return-ok
skip = never
}
passdb {
args =
default_fields =
deny = no
driver = pam
master = no
override_fields =
pass = no
result_failure = continue
result_internalfail = continue
result_success = return-ok
skip = never
}
service auth {
chroot =
client_limit = 0
drop_priv_before_exec = no
executable = auth
extra_groups =
group =
idle_kill = 0
privileged_group =
process_limit = 1
process_min_avail = 0
protocol =
service_count = 0
type =
unix_listener /var/spool/postfix/private/auth {
group = postfix
mode = 0660
user = postfix
}
unix_listener auth-client {
group =
mode = 0600
user = $default_internal_user
}
unix_listener auth-login {
group =
mode = 0600
user = $default_internal_user
}
unix_listener auth-master {
group =
mode = 0600
user =
}
unix_listener auth-userdb {
group =
mode = 0666
user = $default_internal_user
}
unix_listener login/login {
group =
mode = 0666
user =
}
unix_listener token-login/tokenlogin {
group =
mode = 0666
user =
}
user = $default_internal_user
vsz_limit = 18446744073709551615 B
}
userdb {
args =
default_fields = uid=vmail gid=vmail home=/var/spool/mail/%d/%n
driver = static
override_fields =
result_failure = continue
result_internalfail = continue
result_success = return-ok
skip = never
}
userdb {
args =
default_fields =
driver = passwd
override_fields =
result_failure = continue
result_internalfail = continue
result_success = return-ok
skip = never
}
===============================================