freeslkr <freeslkr.wl6x <at> mailnull.com> writes:
Hello,
I'm trying out SELinux on Fedora 8 in permissive mode. I get AVCs
everytime postfix delivers mail to the maildir directories. It looks
like postfix doesn't have permission to create files. For example,
from /var/log/messages:
SELinux is preventing local (postfix_local_t) "link" to
./1208923427.P3686.myhost (mail_spool_t)
from /var/log/audit/audit.log:
type=AVC msg=audit(1208923427.350:95): avc: denied { link } for
pid=3686 comm="local" name="1208923427.P3686.myhost" dev=dm-3
ino=819271 scontext=system_u:system_r:postfix_local_t:s0
tcontext=system_u:object_r:mail_spool_t:s0 tclass=file
type=SYSCALL msg=audit(1208923427.350:95): arch=c000003e
syscall=86 success=yes exit=0 a0=2aaaaad599c0 a1=2aaaaad59ba0
a2=0 a3=0 items=0 ppid=2371 pid=3686 auid=4294967295 uid=0 gid=0
euid=1000 suid=0 fsuid=1000 egid=1000 sgid=0 fsgid=1000 tty=(none)
comm="local" exe="/usr/libexec/postfix/local"
subj=system_u:system_r:postfix_local_t:s0 key=(null)
Is my interpretation correct. If so, is it likely that this could be
corrected in a future policy version?
Thank you for you help
I'll first note that reverting to mbox files in /var/spool/mail works
just fine.
Blundering along here ...
file:///usr/share/doc/selinux-policy-3.0.8/html/services_postfix.html
says
allow_postfix_local_write_mail_spool
Default value: false
Description: Allow postfix_local domain full write access to mail_spool
directories
This sounds like what I need. But, it seems that it's already set.
$ getsebool allow_postfix_local_write_mail_spool
allow_postfix_local_write_mail_spool --> on
$ cd /var/spool
$ ls -Zd mail
drwxrwxr-x root mail system_u:object_r:mail_spool_t:s0 mail
$ ls -Zd mail/*
drwxrwx--- XXXX mail system_u:object_r:mail_spool_t:s0 mail/XXXX
$ ls -Zd mail/*/*
drwxrwx--- XXXX mail system_u:object_r:mail_spool_t:s0 mail/XXXX/cur
drwxrwx--- XXXX mail system_u:object_r:mail_spool_t:s0 mail/XXXX/new
drwxrwx--- XXXX mail system_u:object_r:mail_spool_t:s0 mail/XXXX/tmp
$ ls -Z mail/*/*/new
-rw------- XXXX XXXX system_u:object_r:mail_spool_t:s0
1209227463.Vfd03Ic8046M24695.myhost
To me, it _looks_ postfix should be able to create new files in
/var/spool/mail/*/*, but this is being denied.
In the selinux-policy source rpm, there are three files that seem to be
related to postfix: postfix.{fc,if,te}. Obviously, I don't understand how
all of this works, but there are no direct references to mail_spool_t or
/var/spool/mail or /var/mail in these files.
/var/spool/postfix has type postfix_spool_t, so naively I try
$ chcon --recursive --type postfix_spool_t /var/spool/mail
but that causes numerous AVC denied messages.
Using audit2allow:
$ grep -e postfix -e mail /var/log/audit/audit.log | audit2allow
#============= postfix_local_t ==============
allow postfix_local_t mail_spool_t:file link;
Now, if I can just figure out what to do with this .... Thanks to anyone
that shares some insight here.