Bug 1004705

Summary: SELinux is preventing /usr/sbin/useradd from 'write' accesses on the file /dev/null.
Product: [Fedora] Fedora Reporter: Igor Gnatenko <ignatenko>
Component: livecd-toolsAssignee: Brian Lane <bcl>
Status: CLOSED CURRENTRELEASE QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 20CC: adam.stokes, bcl, bruno, dhuff, dominick.grift, dwalsh, ignatenko, Jasper.Hartline, katzj, lvrabec, mgrepl
Target Milestone: ---   
Target Release: ---   
Hardware: x86_64   
OS: Unspecified   
Whiteboard: abrt_hash:1fd377e4c768db22fb85d65482ea5cab105604ca68c0e86d514804c1c6de956f
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2014-01-14 19:18:53 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:

Description Igor Gnatenko 2013-09-05 09:52:12 UTC
Description of problem:
SELinux is preventing /usr/sbin/useradd from 'write' accesses on the file /dev/null.

*****  Plugin leaks (86.2 confidence) suggests   *****************************

If you want to ignore useradd trying to write access the null file, because you believe it should not need this access.
Then you should report this as a bug.  
You can generate a local policy module to dontaudit this access.
Do
# grep /usr/sbin/useradd /var/log/audit/audit.log | audit2allow -D -M mypol
# semodule -i mypol.pp

*****  Plugin catchall (14.7 confidence) suggests   **************************

If you believe that useradd should be allowed write access on the null file 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 useradd /var/log/audit/audit.log | audit2allow -M mypol
# semodule -i mypol.pp

Additional Information:
Source Context                unconfined_u:unconfined_r:useradd_t:s0-s0:c0.c1023
Target Context                unconfined_u:object_r:device_t:s0
Target Objects                /dev/null [ file ]
Source                        useradd
Source Path                   /usr/sbin/useradd
Port                          <Unknown>
Host                          (removed)
Source RPM Packages           shadow-utils-4.1.5.1-8.fc20.x86_64
Target RPM Packages           
Policy RPM                    selinux-policy-3.12.1-75.fc20.noarch
Selinux Enabled               True
Policy Type                   targeted
Enforcing Mode                Permissive
Host Name                     (removed)
Platform                      Linux (removed) 3.11.0-3.fc20.x86_64 #1 SMP Tue
                              Sep 3 21:52:28 UTC 2013 x86_64 x86_64
Alert Count                   4
First Seen                    2013-09-05 13:50:53 MSK
Last Seen                     2013-09-05 13:51:23 MSK
Local ID                      37be374f-05af-42d0-850b-84af99029b5d

Raw Audit Messages
type=AVC msg=audit(1378374683.421:907): avc:  denied  { write } for  pid=13760 comm="useradd" path="/dev/null" dev="sda2" ino=3943313 scontext=unconfined_u:unconfined_r:useradd_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:device_t:s0 tclass=file


type=SYSCALL msg=audit(1378374683.421:907): arch=x86_64 syscall=execve success=yes exit=0 a0=16c3d00 a1=16c2a60 a2=16c0340 a3=7ffffb925020 items=0 ppid=13753 pid=13760 auid=1000 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 ses=5 tty=pts0 comm=useradd exe=/usr/sbin/useradd subj=unconfined_u:unconfined_r:useradd_t:s0-s0:c0.c1023 key=(null)

Hash: useradd,useradd_t,device_t,file,write

Additional info:
reporter:       libreport-2.1.6
hashmarkername: setroubleshoot
kernel:         3.11.0-3.fc20.x86_64
type:           libreport

Potential duplicate: bug 861281

Comment 1 Igor Gnatenko 2013-09-05 09:53:12 UTC
$ sudo livecd-iso-to-disk --format --efi Fedora-19-x86_64-netinst.iso /dev/sdb

Comment 2 Daniel Walsh 2013-09-05 13:19:01 UTC
Why is livecd-iso-to-disk executing useradd?  And why is /dev/null mislabeled?

Comment 3 Brian Lane 2013-09-05 23:40:41 UTC
I have no idea. litd doesn't call useradd directly and I can't think of any reason for the format or efi paths to be using it indirectly.

Is it possible for the reporter to try and debug this a bit more?

Comment 4 Igor Gnatenko 2013-09-06 04:33:24 UTC
(In reply to Brian C. Lane from comment #3)
> I have no idea. litd doesn't call useradd directly and I can't think of any
> reason for the format or efi paths to be using it indirectly.
> 
> Is it possible for the reporter to try and debug this a bit more?
Sure. Let me discover what I should to do.

Comment 5 Lukas Vrabec 2013-10-11 11:03:30 UTC
*** Bug 1004706 has been marked as a duplicate of this bug. ***

Comment 6 Brian Lane 2014-01-14 19:18:53 UTC
This is working fine for me on F20 with the host in Enforcing mode (see bug 1051523)