Bug 522380

Summary: setroubleshoot: SELinux is preventing vbetool "mmap_zero" access on <Unknown>.
Product: [Fedora] Fedora Reporter: Rodd Clarkson <rodd>
Component: selinux-policyAssignee: Daniel Walsh <dwalsh>
Status: CLOSED DUPLICATE QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: low    
Version: rawhideCC: ajax, atodorov, dwalsh, eparis, mgrepl
Target Milestone: ---Keywords: Reopened
Target Release: ---   
Hardware: x86_64   
OS: Linux   
Whiteboard: setroubleshoot_trace_hash:2eaa3b6c17b0dec9dbea7a4862b004af2b34ba9fd312c1bea983aaac007b28b5
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2009-10-20 17:34:07 EDT Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:

Description Rodd Clarkson 2009-09-10 05:08:32 EDT
The following was filed automatically by setroubleshoot:

Summary:

SELinux is preventing vbetool "mmap_zero" access on <Unknown>.

Detailed Description:

[vbetool has a permissive type (vbetool_t). This access was not denied.]

SELinux denied access requested by vbetool. The current boolean settings do not
allow this access. If you have not setup vbetool to require this access this may
signal an intrusion attempt. If you do intend this access you need to change the
booleans on this system to allow the access.

Allowing Access:

Confined processes can be configured to to run requiring different access,
SELinux provides booleans to allow you to turn on/off access as needed. The
boolean mmap_low_allowed is set incorrectly.
Boolean Description:
Allow certain domains to map low memory in the kernel


Fix Command:

# setsebool -P mmap_low_allowed 1

Additional Information:

Source Context                system_u:system_r:vbetool_t:s0-s0:c0.c1023
Target Context                system_u:system_r:vbetool_t:s0-s0:c0.c1023
Target Objects                None [ memprotect ]
Source                        vbetool
Source Path                   /usr/sbin/vbetool
Port                          <Unknown>
Host                          (removed)
Source RPM Packages           vbetool-1.2.1-1.fc12
Target RPM Packages           
Policy RPM                    selinux-policy-3.6.30-4.fc12
Selinux Enabled               True
Policy Type                   targeted
MLS Enabled                   True
Enforcing Mode                Enforcing
Plugin Name                   catchall_boolean
Host Name                     (removed)
Platform                      Linux (removed)
                              2.6.31-0.125.4.2.rc5.git2.fc12.x86_64 #1 SMP Tue
                              Aug 11 21:00:45 EDT 2009 x86_64 x86_64
Alert Count                   6
First Seen                    Thu 10 Sep 2009 07:53:42 EST
Last Seen                     Thu 10 Sep 2009 19:07:21 EST
Local ID                      f7610e37-3869-489b-bc36-25e2fd111a3c
Line Numbers                  

Raw Audit Messages            

node=(removed) type=AVC msg=audit(1252573641.381:37): avc:  denied  { mmap_zero } for  pid=2350 comm="vbetool" scontext=system_u:system_r:vbetool_t:s0-s0:c0.c1023 tcontext=system_u:system_r:vbetool_t:s0-s0:c0.c1023 tclass=memprotect

node=(removed) type=SYSCALL msg=audit(1252573641.381:37): arch=c000003e syscall=9 success=yes exit=0 a0=0 a1=502 a2=7 a3=11 items=0 ppid=2338 pid=2350 auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=4294967295 comm="vbetool" exe="/usr/sbin/vbetool" subj=system_u:system_r:vbetool_t:s0-s0:c0.c1023 key=(null)


audit2allow suggests:

#============= vbetool_t ==============
allow vbetool_t self:memprotect mmap_zero;
Comment 1 Daniel Walsh 2009-09-10 10:22:21 EDT
Did you turn on the boolean?

This is a configuration issue, turn the boolean on and vbetool will work for you.
Comment 2 Alexander Todorov 2009-09-15 08:34:54 EDT
I see similar issue with default rawhide install:

type=1400 audit(1253010534.078:7): avc:  denied  { mmap_zero } for  pid=434 comm="vbetool" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=memprotect


Shoudn't vbetool turn this boolean on by default ?
Comment 3 Daniel Walsh 2009-09-15 08:39:40 EDT
Did you see any problem from not having the boolean turned on?  Does your machine successfully Suspend/Resume?
Comment 4 Alexander Todorov 2009-09-15 08:53:46 EDT
This was from automated test run. I have only shell access to this machine and I'm not sure if I can test suspend/resume via serial console.
Comment 5 Daniel Walsh 2009-09-15 11:11:44 EDT
The problem here is the boolean is all on or all off.
With the boolean turned off, we can prevent unconfined users/admin from accidentally executing mmap_zero applications, allowing them to take over the machine.  I guess since the standard is now to require root access, I can turn the boolean on by default.  The only other app besides vbetool that needs this access is wine.
Comment 6 Daniel Walsh 2009-10-20 17:34:07 EDT

*** This bug has been marked as a duplicate of bug 528022 ***