Bug 700475 - colord causing 'sys_admin' AVC during startup
Summary: colord causing 'sys_admin' AVC during startup
Keywords:
Status: CLOSED RAWHIDE
Alias: None
Product: Fedora
Classification: Fedora
Component: colord
Version: 19
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: ---
Assignee: Richard Hughes
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2011-04-28 13:40 UTC by Tom London
Modified: 2013-10-30 15:46 UTC (History)
6 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2013-10-30 15:46:17 UTC
Type: ---


Attachments (Terms of Use)

Description Tom London 2011-04-28 13:40:58 UTC
Description of problem:
I'm noticing the following AVC on every boot.  Does colord need this capability?

#============= colord_t ==============
allow colord_t self:capability sys_admin;

Here is the raw AVC:

type=AVC msg=audit(1303995798.951:22): avc:  denied  { sys_admin } for
 pid=1161 comm="colord" capability=21
scontext=system_u:system_r:colord_t:s0-s0:c0.c1023
tcontext=system_u:system_r:colord_t:s0-s0:c0.c1023 tclass=capability
type=SYSCALL msg=audit(1303995798.951:22): arch=c000003e syscall=2
success=yes exit=19 a0=7fffe330fc50 a1=802 a2=7fffe330fc58 a3=3
items=0 ppid=1 pid=1161 auid=4294967295 uid=0 gid=0 euid=0 suid=0
fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=4294967295 comm="colord"
exe="/usr/libexec/colord"
subj=system_u:system_r:colord_t:s0-s0:c0.c1023 key=(null)

and here is the output from sealert:


SELinux is preventing /usr/libexec/colord from using the sys_admin capability.

*****  Plugin catchall (100. confidence) suggests  ***************************

If you believe that colord should have the sys_admin capability by default.
Then you should report this as a bug.
You can generate a local policy module to allow this access.
Do
allow this access for now by executing:
# grep colord /var/log/audit/audit.log | audit2allow -M mypol
# semodule -i mypol.pp

Additional Information:
Source Context                system_u:system_r:colord_t:s0-s0:c0.c1023
Target Context                system_u:system_r:colord_t:s0-s0:c0.c1023
Target Objects                Unknown [ capability ]
Source                        colord
Source Path                   /usr/libexec/colord
Port                          <Unknown>
Host                          tlondon.localhost.org
Source RPM Packages           colord-0.1.6-1.fc16
Target RPM Packages
Policy RPM                    selinux-policy-3.9.16-15.fc16
Selinux Enabled               True
Policy Type                   targeted
Enforcing Mode                Enforcing
Host Name                     tlondon.localhost.org
Platform                      Linux tlondon.localhost.org
                             2.6.39-0.rc4.git2.0.fc16.x86_64 #1 SMP Thu Apr 21
                             02:24:19 UTC 2011 x86_64 x86_64
Alert Count                   4
First Seen                    Wed 27 Apr 2011 06:37:56 AM PDT
Last Seen                     Thu 28 Apr 2011 06:03:18 AM PDT
Local ID                      013dd854-645a-4b1c-9337-f5d186a96c4f

Raw Audit Messages
type=AVC msg=audit(1303995798.952:24): avc:  denied  { sys_admin } for
 pid=1161 comm="colord" capability=21
scontext=system_u:system_r:colord_t:s0-s0:c0.c1023
tcontext=system_u:system_r:colord_t:s0-s0:c0.c1023 tclass=capability


type=SYSCALL msg=audit(1303995798.952:24): arch=x86_64 syscall=open
success=yes exit=ENODEV a0=7fffe330fc50 a1=882 a2=5 a3=7fffe330e3b0
items=0 ppid=1 pid=1161 auid=4294967295 uid=0 gid=0 euid=0 suid=0
fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=4294967295 comm=colord
exe=/usr/libexec/colord subj=system_u:system_r:colord_t:s0-s0:c0.c1023
key=(null)

Hash: colord,colord_t,colord_t,capability,sys_admin

audit2allow

#============= colord_t ==============
allow colord_t self:capability sys_admin;

audit2allow -R

Version-Release number of selected component (if applicable):
colord-0.1.6-1.fc16

How reproducible:
Every boot

Steps to Reproduce:
1. Boot
2.
3.
  
Actual results:


Expected results:


Additional info:

Comment 1 Richard Hughes 2011-04-28 13:51:19 UTC
What is 'sys_admin'? Thanks.

Comment 2 Tom London 2011-04-28 14:41:49 UTC
From previous BZ: https://bugzilla.redhat.com/show_bug.cgi?id=541217#c3

sys_admin is the catchall capability.  Not really an SELinux thing.

    * Allow configuration of the secure attention key
    * Allow administration of the random device
    * Allow examination and configuration of disk quotas
    * Allow configuring the kernel's syslog (printk behaviour)
    * Allow setting the domainname
    * Allow setting the hostname
    * Allow calling bdflush()
    * Allow mount() and umount(), setting up new smb connection
    * Allow some autofs root ioctls
    * Allow nfsservctl
    * Allow VM86_REQUEST_IRQ
    * Allow to read/write pci config on alpha
    * Allow irix_prctl on mips (setstacksize)
    * Allow flushing all cache on m68k (sys_cacheflush)
    * Allow removing semaphores (Used instead of CAP_CHOWN to "chown" IPC
message queues, semaphores and shared memory)
    * Allow locking/unlocking of shared memory segment
    * Allow turning swap on/off
    * Allow forged pids on socket credentials passing
    * Allow setting readahead and flushing buffers on block devices
    * Allow setting geometry in floppy driver
    * Allow turning DMA on/off in xd driver
    * Allow administration of md devices (mostly the above, but some extra
ioctls)
    * Allow tuning the ide driver
    * Allow access to the nvram device
    * Allow administration of apm_bios, serial and bttv (TV) device
    * Allow manufacturer commands in isdn CAPI support driver
    * Allow reading non-standardized portions of pci configuration space
    * Allow DDI debug ioctl on sbpcd driver
    * Allow setting up serial ports
    * Allow sending raw qic-117 commands
    * Allow enabling/disabling tagged queuing on SCSI controllers and sending
arbitrary SCSI commands
    * Allow setting encryption key on loopback filesystem
    * Allow setting zone reclaim policy

Comment 3 Daniel Walsh 2011-04-28 14:46:36 UTC
Is colord doing something with namespacing or mount?

Comment 4 Richard Hughes 2011-04-28 15:16:33 UTC
(In reply to comment #3)
> Is colord doing something with namespacing or mount?

Nope. I can't see anything in sys_admin that colord is doing.

Richard.

Comment 5 Daniel Walsh 2011-04-28 18:44:41 UTC
Maybe the kernel guys would have an idea?

Comment 6 Eric Paris 2011-04-28 18:57:49 UTC
Can you reproduce under strace?  It might give us a better idea what file it is trying to open (and why that might require cap_sys_admin)

Comment 7 Stephen Smalley 2011-04-28 19:44:44 UTC
Or retry with a syscall filter enabled so we get a PATH record, e.g.
/sbin/auditctl -w /etc/shadow -p w
and then restart.
The actual filter doesn't matter; there just needs to be at least one filter for the audit system to start collecting PATH information.

Comment 8 Daniel Walsh 2011-04-28 20:40:11 UTC
Tom could you do that on your machine all the time.

I have  

-w /etc/shadow -p w

in /etc/audit/audit.rules 

Which turns on full auditing, and will give you path  information always.

Comment 9 Tom London 2011-04-28 20:48:51 UTC
Sure.  I'll do so when I get back home later today.

I'll then run the test and report back.

Comment 10 Tom London 2011-04-29 02:03:31 UTC
Here is what I see after adding '' to /etc/audit/audit.rules and then rebooting:

type=AVC msg=audit(1304041886.295:24): avc:  denied  { sys_admin } for  pid=1193 comm="colord" capability=21  scontext=system_u:system_r:colord_t:s0-s0:c0.c1023 tcontext=system_u:system_r:colord_t:s0-s0:c0.c1023 tclass=capability
type=SYSCALL msg=audit(1304041886.295:24): arch=c000003e syscall=2 success=yes exit=19 a0=7fffee51bc80 a1=802 a2=7fffee51bc88 a3=3 items=1 ppid=1 pid=1193 auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=4294967295 comm="colord" exe="/usr/libexec/colord" subj=system_u:system_r:colord_t:s0-s0:c0.c1023 key=(null)
type=CWD msg=audit(1304041886.295:24):  cwd="/"
type=PATH msg=audit(1304041886.295:24): item=0 name="/dev/sg2" inode=7575 dev=00:05 mode=020660 ouid=0 ogid=6 rdev=15:02 obj=system_u:object_r:scsi_generic_device_t:s0

[The above was repeated 2 more times.]

For completeness:

[root@tlondon ~]# ls -l /dev/sg*
crw-rw----. 1 root disk  21, 0 Apr 28 18:51 /dev/sg0
crw-rw----+ 1 root cdrom 21, 1 Apr 28 18:51 /dev/sg1
crw-rw----. 1 root disk  21, 2 Apr 28 18:51 /dev/sg2
[root@tlondon ~]# ls -lZ /dev/sg*
crw-rw----. root disk  system_u:object_r:scsi_generic_device_t:s0 /dev/sg0
crw-rw----+ root cdrom system_u:object_r:scsi_generic_device_t:s0 /dev/sg1
crw-rw----. root disk  system_u:object_r:scsi_generic_device_t:s0 /dev/sg2
[root@tlondon ~]#

Comment 11 Tom London 2011-05-01 20:33:44 UTC
So if I unplug a FAT formatted SD card before I boot, this AVC goes away. Guessing that's what /dev/sg2 links to.

Comment 12 Daniel Walsh 2011-05-02 14:10:57 UTC
I guess we can dontaudit this for now and see if it causes any problems.

Comment 13 Fedora End Of Life 2013-04-03 17:20:21 UTC
This bug appears to have been reported against 'rawhide' during the Fedora 19 development cycle.
Changing version to '19'.

(As we did not run this process for some time, it could affect also pre-Fedora 19 development
cycle bugs. We are very sorry. It will help us with cleanup during Fedora 19 End Of Life. Thank you.)

More information and reason for this action is here:
https://fedoraproject.org/wiki/BugZappers/HouseKeeping/Fedora19

Comment 14 Richard Hughes 2013-10-30 15:46:17 UTC
colord is not loading profiles of other volumes now.


Note You need to log in before you can comment on or make changes to this bug.