Bug 951819 - SELinux is preventing /usr/bin/bash from using the 'transition' accesses on a process.
Summary: SELinux is preventing /usr/bin/bash from using the 'transition' accesses on a...
Alias: None
Product: Fedora
Classification: Fedora
Component: selinux-policy
Version: 18
Hardware: x86_64
OS: Unspecified
Target Milestone: ---
Assignee: Miroslav Grepl
QA Contact: Fedora Extras Quality Assurance
Whiteboard: abrt_hash:1f113abaef8325a956f8e251352...
Depends On:
TreeView+ depends on / blocked
Reported: 2013-04-13 12:39 UTC by Mads Kiilerich
Modified: 2013-04-20 01:02 UTC (History)
4 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Last Closed: 2013-04-20 01:02:31 UTC

Attachments (Terms of Use)

Description Mads Kiilerich 2013-04-13 12:39:03 UTC
Description of problem:
Trying to build a livecd I got this error.

I was launching livecd-creator from a sh script in my home directory, launching it with sudo.

It is m understanding that it should work with SE enabled - or at least give a hint and option for making it work.
SELinux is preventing /usr/bin/bash from using the 'transition' accesses on a process.

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

If you believe that bash should be allowed transition access on processes labeled rpm_script_t by default.
Then you should report this as a bug.
You can generate a local policy module to allow this access.
allow this access for now by executing:
# grep sh /var/log/audit/audit.log | audit2allow -M mypol
# semodule -i mypol.pp

Additional Information:
Source Context                unconfined_u:system_r:livecd_t:s0-s0:c0.c1023
Target Context                unconfined_u:system_r:rpm_script_t:s0-s0:c0.c1023
Target Objects                /usr/bin/bash [ process ]
Source                        sh
Source Path                   /usr/bin/bash
Port                          <Unknown>
Host                          (removed)
Source RPM Packages           bash-4.2.45-1.fc18.x86_64
Target RPM Packages           bash-4.2.45-1.fc18.x86_64
Policy RPM                    selinux-policy-3.11.1-87.fc18.noarch
Selinux Enabled               True
Policy Type                   targeted
Enforcing Mode                Permissive
Host Name                     (removed)
Platform                      Linux (removed) 3.8.3-201.fc18.x86_64 #1 SMP Thu
                              Mar 14 21:28:05 UTC 2013 x86_64 x86_64
Alert Count                   1
First Seen                    2013-04-13 14:31:59 CEST
Last Seen                     2013-04-13 14:31:59 CEST
Local ID                      07528517-7bf7-4510-9dbe-4a78e5c7425c

Raw Audit Messages
type=AVC msg=audit(1365856319.736:1950): avc:  denied  { transition } for  pid=13289 comm="rpm" path="/usr/bin/bash" dev="loop0" ino=136535 scontext=unconfined_u:system_r:livecd_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:rpm_script_t:s0-s0:c0.c1023 tclass=process

type=SYSCALL msg=audit(1365856319.736:1950): arch=x86_64 syscall=execve per=8 success=yes exit=0 a0=16dc800 a1=16ed6b0 a2=16e7320 a3=20 items=0 ppid=13288 pid=13289 auid=1000 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 ses=2 tty=pts6 comm=sh exe=/usr/bin/bash subj=unconfined_u:system_r:rpm_script_t:s0-s0:c0.c1023 key=(null)

Hash: sh,livecd_t,rpm_script_t,process,transition


#============= livecd_t ==============
allow livecd_t rpm_script_t:process transition;

audit2allow -R
require {
	type livecd_t;

#============= livecd_t ==============

Additional info:
hashmarkername: setroubleshoot
kernel:         3.8.3-201.fc18.x86_64
type:           libreport

Comment 1 Daniel Walsh 2013-04-16 21:21:06 UTC
Miroslav do you think this is a bug in livecd tool, since it is not supposed to be doing SELinux stuff within the build.

Mads, did the live image build correctly?

Comment 2 Mads Kiilerich 2013-04-16 22:15:15 UTC
Yes, it seems like it did build and work correctly.

Hmm ... could it be because I in a %post --nochroot section do a rpm -q ? But I assume read-only operations is ok - everything should be allowed in a %post --nochroot section.

Comment 3 Daniel Walsh 2013-04-17 20:16:52 UTC
Well a post install would cause a rpm_script_transition, but not sure what you mean by this.  

Did you install a special rpm?  into a livecd?

Comment 4 Mads Kiilerich 2013-04-17 20:33:16 UTC
Yes, the .ks will also do something like
  %post --nochroot
  rpm --root $INSTALL_ROOT -i -f --nodeps .../xxx.rpm
to install a RPM without installing all dependencies.

What I had in mind was another useful use of rpm in %post --nochroot:
  rpm -q livecd-tools > $INSTALL_ROOT/versions.txt

Comment 5 Daniel Walsh 2013-04-17 20:56:14 UTC
I guess we should add the transition, since we want the post install scripts to run, but we relabel at the end so it should fix it up.

I wish livecd_tools was like mock and did no SELinux actions.

Comment 6 Mads Kiilerich 2013-04-17 21:20:15 UTC
From my point of view: %post sections are custom shell scripts and the user run them as root. Any kind of limitations of what can be done from them will hit some livecd-tool user - you shouldn't try. This error was just the example I hit. I don't think that allowing that transition would make a significant difference.

You could perhaps lock ordinary %post sections down so they can't escape from the chroot ... but I don't think it is worth it.

Comment 7 Daniel Walsh 2013-04-17 22:44:53 UTC
587e992cd2f55fab53425fe6e8dea58a36fc619c fixes this in git.

Comment 8 Fedora Update System 2013-04-18 12:51:16 UTC
selinux-policy-3.11.1-91.fc18 has been submitted as an update for Fedora 18.

Comment 9 Fedora Update System 2013-04-19 04:48:50 UTC
Package selinux-policy-3.11.1-91.fc18:
* should fix your issue,
* was pushed to the Fedora 18 testing repository,
* should be available at your local mirror within two days.
Update it with:
# su -c 'yum update --enablerepo=updates-testing selinux-policy-3.11.1-91.fc18'
as soon as you are able to.
Please go to the following url:
then log in and leave karma (feedback).

Comment 10 Fedora Update System 2013-04-20 01:02:33 UTC
selinux-policy-3.11.1-91.fc18 has been pushed to the Fedora 18 stable repository.  If problems still persist, please make note of it in this bug report.

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