updpwd AVC

[Tony Molloy]

On Monday 26 September 2011 22:22:31 Dominick Grift wrote:
> On Mon, 2011-09-26 at 15:00 +0100, Tony Molloy wrote:
> > Hi,
> > 
> > 
> > On a fully updated CentOS 5.7 box I get the following AVC
> > 
> > 
> > Summary:
> > 
> > 
> > SELinux is preventing unix_update (updpwd_t) "getattr" to /
> > (fs_t).
> > 
> > 
> > Detailed Description:
> > 
> > 
> > SELinux denied access requested by unix_update. It is not
> > expected that this
> > 
> > access is required by unix_update and this access may signal an
> > intrusion
> > 
> > attempt. It is also possible that the specific version or
> > configuration of the
> > 
> > application is causing it to require additional access.
> > 
> > 
> > Allowing Access:
> > 
> > 
> > You can generate a local policy module to allow this access - see
> > FAQ
> > 
> > (http://fedora.redhat.com/docs/selinux-faq-fc5/#id2961385) Or you
> > can disable
> > 
> > SELinux protection altogether. Disabling SELinux protection is
> > not recommended.
> > 
> > Please file a bug report
> > (http://bugzilla.redhat.com/bugzilla/enter_bug.cgi)
> > 
> > against this package.
> > 
> > 
> > Additional Information:
> > 
> > 
> > Source Context system_u:system_r:updpwd_t
> > 
> > Target Context system_u:object_r:fs_t
> > 
> > Target Objects / [ filesystem ]
> > 
> > Source unix_update
> > 
> > Source Path <Unknown>
> > 
> > Port <Unknown>
> > 
> > Host a.b.c.d
> > 
> > Source RPM Packages
> > 
> > Target RPM Packages filesystem-2.4.0-3.el5.centos
> > 
> > Policy RPM selinux-policy-2.4.6-316.el5
> > 
> > Selinux Enabled True
> > 
> > Policy Type targeted
> > 
> > MLS Enabled True
> > 
> > Enforcing Mode Enforcing
> > 
> > Plugin Name catchall
> > 
> > Host Name a.b.c.d
> > 
> > Platform Linuxl a.b.c.d 2.6.18-274.3.1.el5
> > 
> > #1 SMP Tue Sep 6 20:13:52 EDT 2011 x86_64 x86_64
> > 
> > Alert Count 11
> > 
> > First Seen Fri Feb 25 15:39:33 2011
> > 
> > Last Seen Mon Sep 26 14:18:54 2011
> > 
> > Local ID 275eef01-114a-419b-9df0-4bb81932bc5e
> > 
> > Line Numbers
> > 
> > 
> > Raw Audit Messages
> > 
> > 
> > host=a.b.c.d type=AVC msg=audit(1317043134.620:3620): avc: denied
> > { getattr } for pid=21354 comm="unix_update" name="/" dev=sda5
> > ino=2 scontext=system_u:system_r:updpwd_t:s0
> > tcontext=system_u:object_r:fs_t:s0 tclass=filesystem
> > 
> > 
> > 
> > I can generate a local policy module.
> 
> Any idea what you were doing when this happened? The reason i ask
> is because this is not even allowed in latest fedora as far as i
> can see.
> 

This machine is basically a mail and ftp server. As far as I can tell 
from the logs ( secure and messages ) nobody was doing anything on the 
machine at the times I get the AVC, 5 times yesterday.

> It is no big deal to allow updpwd_t to get attributes of the fs_t
> filesystem but it is certainly not common for updpwd_t to want this
> access i believe. If it was we probably would have gotten may more
> reports much earlier.
> 

Strange then that I am getting it from this one server only.

Here's the context for unix_update

-rwx------  root root system_u:object_r:updpwd_exec_t  
/sbin/unix_update

I've just run an autorelabel on the entire filesystem as part of the 
5.6 to 5.7 CentOS update

Thanks,

Tony

> > Thanks,
> > 
> > 
> > Tony
> > 
> > --
> > selinux mailing list
> > selinux at lists.fedoraproject.org
> > https://admin.fedoraproject.org/mailman/listinfo/selinux
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