Bug 809899 - SELinux is preventing systemd from write ac cess on the directory /
Summary: SELinux is preventing systemd from write ac cess on the directory /
Keywords:
Status: CLOSED CANTFIX
Alias: None
Product: Fedora
Classification: Fedora
Component: systemd
Version: 16
Hardware: i686
OS: Linux
unspecified
low
Target Milestone: ---
Assignee: systemd-maint
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2012-04-04 15:51 UTC by Klaus Lichtenwalder
Modified: 2012-06-07 08:33 UTC (History)
7 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2012-06-07 08:33:30 UTC
Type: Bug


Attachments (Terms of Use)
denials after boot in permissive mode (1.07 KB, text/plain)
2012-04-11 19:02 UTC, Klaus Lichtenwalder
no flags Details
denials after boot in enforcing mode (21.22 KB, text/plain)
2012-04-11 19:02 UTC, Klaus Lichtenwalder
no flags Details

Description Klaus Lichtenwalder 2012-04-04 15:51:56 UTC
Description of problem:
After resume from hibernation (if important)
time->Wed Apr  4 17:34:11 2012
type=AVC msg=audit(1333553651.616:318): avc:  denied  { write } for  pid=3858 comm="systemd" name="/" dev="sda3" ino=2 scontext=system_u:system_r:init_t:s0 tcontext=system_u:object_r:root_t:s0 tclass=dir


Version-Release number of selected component (if applicable):
klaus@acer:~$ rpm -qa selinux\*;rpm -qa systemd\*
selinux-policy-3.10.0-80.fc16.noarch
selinux-policy-targeted-3.10.0-80.fc16.noarch
systemd-37-17.fc16.i686
systemd-units-37-17.fc16.i686
systemd-sysv-37-17.fc16.i686


How reproducible:
This came after the last update

Additional info:

System uses confined users, but up to now this message did not show up

Comment 1 Michal Schmidt 2012-04-04 16:35:48 UTC
Does the AVC message have an associated SYSCALL message with the same timestamp in /var/log/audit/audit.log? If yes, could you paste it?

Comment 2 Klaus Lichtenwalder 2012-04-04 17:13:03 UTC
No, I did check. Looking into audit.log I find the following two entries with matching timestamps:

type=SERVICE_STOP msg=audit(1333553651.568:316): pid=0 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 msg=' comm="atd" exe="/bin/systemd" hostname=? addr=? terminal=? res=success'
type=ANOM_ABEND msg=audit(1333553651.615:317): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=system_u:system_r:init_t:s0 pid=3858 comm="systemd" reason="memory violation" sig=11

Comment 3 Bill Nottingham 2012-04-10 19:44:22 UTC
So, is the write access... a core dump?

Comment 4 Lennart Poettering 2012-04-11 12:53:50 UTC
Hmm, looks like you managed to get systemd to crash. I'd be really interested in getting a backtrace for that...

Comment 5 Klaus Lichtenwalder 2012-04-11 19:01:28 UTC
Hi,
yes, obviously it's a core dump, or at least trying to core dump. I tried to get all messages that I could find relevant to this.
It looks like this didn't happen since Apr 4. I don't know why, as I can't find any relevant update around this time. What I could find is:

type=SERVICE_STOP msg=audit(1333553651.568:316): pid=0 uid=0 auid=4294967295 ses
=4294967295 subj=system_u:system_r:init_t:s0 msg=' comm="atd" exe="/bin/systemd"
 hostname=? addr=? terminal=? res=success'
type=ANOM_ABEND msg=audit(1333553651.615:317): auid=4294967295 uid=0 gid=0 ses=4
294967295 subj=system_u:system_r:init_t:s0 pid=3858 comm="systemd" reason="memor
y violation" sig=11
type=AVC msg=audit(1333553651.616:318): avc:  denied  { write } for  pid=3858 comm="systemd" name="/" dev="sda3" ino=2 scontext=system_u:system_r:init_t:s0 tcontext=system_u:object_r:root_t:s0 tclass=dir

Correlating to messages:

Apr  4 17:34:11 acer dbus[867]: [system] Successfully activated service 'org.freedesktop.PackageKit'
Apr  4 17:34:11 acer dbus-daemon[867]: dbus[867]: [system] Successfully activated service 'org.freedesktop.PackageKit'
Apr  4 17:34:11 acer kernel: [ 7064.570122] systemd[1]: segfault at f11 ip 08084010 sp bfe309d0 error 6 in systemd[8048000+d8000]
Apr  4 17:34:11 acer systemd[1]: Caught <SEGV>, core dump failed.
Apr  4 17:34:11 acer systemd[1]: Freezing execution.


I guess I was running in enforcing then. I tried to recreate this with permissive, but this does not happen again at the moment, but there's a handful of new avc's. I'll add this in the attachment. Basically, systemd is not allowed to do some things at startup. There are different denials with enforcing and permissive.

Klaus

Comment 6 Klaus Lichtenwalder 2012-04-11 19:02:24 UTC
Created attachment 576841 [details]
denials after boot in permissive mode

Comment 7 Klaus Lichtenwalder 2012-04-11 19:02:53 UTC
Created attachment 576842 [details]
denials after boot in enforcing mode

Comment 8 Klaus Lichtenwalder 2012-04-11 19:04:37 UTC
Just to clarify: the original message for the bug was from thawing after hibernation, the attachment are from a fresh boot. Right now it looks like I have no denials from resuming, as far as I can tell, don't know whether I can catch all messages

Comment 9 Michal Schmidt 2012-04-12 11:50:31 UTC
The crash after hibernation could have been due to a kernel bug and the resulting memory corruption.

Comment 10 Michal Schmidt 2012-06-07 08:33:30 UTC
I'm going with the theory of memory corruption at hibernation and closing this as CANTFIX. If there were a reliable reproducer, the kernel maintainers might be able to do something about it. Otherwise there's little we can do.

If you're still seeing AVC denials during fresh boot with the latest updates, please report them against selinux-policy.


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