Bug 629560 - SELinux is preventing /bin/mount "write" access to /sys/kernel/debug
Summary: SELinux is preventing /bin/mount "write" access to /sys/kernel/debug
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Fedora
Classification: Fedora
Component: selinux-policy-targeted
Version: 14
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Daniel Walsh
QA Contact: Ben Levenson
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2010-09-02 11:32 UTC by Jeff Layton
Modified: 2014-06-18 07:40 UTC (History)
1 user (show)

Fixed In Version: selinux-policy-3.9.3-4.fc14
Clone Of:
Environment:
Last Closed: 2010-09-23 12:44:08 UTC
Type: ---
Embargoed:


Attachments (Terms of Use)

Description Jeff Layton 2010-09-02 11:32:31 UTC
I got this SELinux warning today on f14. The suggested fix is to relabel debugfs, but that seems like it wouldn't stick. Perhaps the policy needs to be fixed to allow access to debugfs_t?

Let me know if you need other info...

----------------------------[snip]---------------------------

Summary:

SELinux is preventing /bin/mount "write" access to /sys/kernel/debug.

Detailed Description:

SELinux denied access requested by mount. /sys/kernel/debug may be a mislabeled.
/sys/kernel/debug default SELinux type is sysfs_t, but its current type is
debugfs_t. Changing this file back to the default type, may fix your problem.

File contexts can be assigned to a file in the following ways.

  * Files created in a directory receive the file context of the parent
    directory by default.
  * The SELinux policy might override the default label inherited from the
    parent directory by specifying a process running in context A which creates
    a file in a directory labeled B will instead create the file with label C.
    An example of this would be the dhcp client running with the dhclient_t type
    and creating a file in the directory /etc. This file would normally receive
    the etc_t type due to parental inheritance but instead the file is labeled
    with the net_conf_t type because the SELinux policy specifies this.
  * Users can change the file context on a file using tools such as chcon, or
    restorecon.

This file could have been mislabeled either by user error, or if an normally
confined application was run under the wrong domain.

However, this might also indicate a bug in SELinux because the file should not
have been labeled with this type.

If you believe this is a bug, please file a bug report against this package.

Allowing Access:

You can restore the default system context to this file by executing the
restorecon command. restorecon '/sys/kernel/debug', if this file is a directory,
you can recursively restore using restorecon -R '/sys/kernel/debug'.

Fix Command:

/sbin/restorecon '/sys/kernel/debug'

Additional Information:

Source Context                system_u:system_r:mount_t:s0
Target Context                system_u:object_r:debugfs_t:s0
Target Objects                /sys/kernel/debug [ dir ]
Source                        mount
Source Path                   /bin/mount
Port                          <Unknown>
Host                          corrin.poochiereds.net
Source RPM Packages           util-linux-ng-2.18-4.fc14
Target RPM Packages           
Policy RPM                    selinux-policy-3.9.0-2.fc14
Selinux Enabled               True
Policy Type                   targeted
Enforcing Mode                Enforcing
Plugin Name                   restorecon
Host Name                     corrin.poochiereds.net
Platform                      Linux corrin.poochiereds.net
                              2.6.35.4-12.fc14.x86_64 #1 SMP Fri Aug 27 07:45:05
                              UTC 2010 x86_64 x86_64
Alert Count                   2
First Seen                    Wed 01 Sep 2010 07:04:30 AM EDT
Last Seen                     Thu 02 Sep 2010 07:30:36 AM EDT
Local ID                      e9310fee-a424-4f9a-83b7-6e89074a98cd
Line Numbers                  

Raw Audit Messages            

node=corrin.poochiereds.net type=AVC msg=audit(1283427036.480:23): avc:  denied  { write } for  pid=5629 comm="mount" name="/" dev=debugfs ino=1 scontext=system_u:system_r:mount_t:s0 tcontext=system_u:object_r:debugfs_t:s0 tclass=dir

node=corrin.poochiereds.net type=SYSCALL msg=audit(1283427036.480:23): arch=c000003e syscall=21 success=no exit=-13 a0=7fdea4529100 a1=2 a2=0 a3=7fffc0199e10 items=0 ppid=1 pid=5629 auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=4294967295 comm="mount" exe="/bin/mount" subj=system_u:system_r:mount_t:s0 key=(null)

Comment 1 Daniel Walsh 2010-09-02 15:12:10 UTC
You can add these rules for now using

# grep avc /var/log/audit/audit.log | audit2allow -M mypol
# semodule -i mypol.pp

Fixed in selinux-policy-3.9.2-1.fc14

Comment 2 Fedora Update System 2010-09-10 16:49:05 UTC
selinux-policy-3.9.3-4.fc14 has been submitted as an update for Fedora 14.
https://admin.fedoraproject.org/updates/selinux-policy-3.9.3-4.fc14

Comment 3 Fedora Update System 2010-09-11 02:16:59 UTC
selinux-policy-3.9.3-4.fc14 has been pushed to the Fedora 14 testing repository.  If problems still persist, please make note of it in this bug report.
 If you want to test the update, you can install it with 
 su -c 'yum --enablerepo=updates-testing update selinux-policy'.  You can provide feedback for this update here: https://admin.fedoraproject.org/updates/selinux-policy-3.9.3-4.fc14

Comment 4 Fedora Update System 2010-09-23 12:40:47 UTC
selinux-policy-3.9.3-4.fc14 has been pushed to the Fedora 14 stable repository.  If problems still persist, please make note of it in this bug report.


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