Bug 531746

Summary: SELinux is preventing /usr/bin/xauth access to a leaked unix_stream_socket file descriptor.
Product: [Fedora] Fedora Reporter: Ruben Vermeersch <ruben>
Component: selinux-policyAssignee: Daniel Walsh <dwalsh>
Status: CLOSED RAWHIDE QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: low    
Version: rawhideCC: bugzilla.redhat.com, dwalsh, meyering, mgrepl, mhlavink, ruben, twhite
Target Milestone: ---Keywords: Reopened
Target Release: ---   
Hardware: x86_64   
OS: Linux   
Whiteboard: setroubleshoot_trace_hash:ecb68fa340af2f93f64e26a5c9a0216cdeb1a2bc9cadc2fc5ad62763fd0aa803
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2009-11-04 13:33:22 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 532748    

Description Ruben Vermeersch 2009-10-29 11:38:50 UTC
Summary:

SELinux is preventing /usr/bin/xauth access to a leaked unix_stream_socket file
descriptor.

Detailed Description:

[xauth has a permissive type (xauth_t). This access was not denied.]

SELinux denied access requested by the xauth command. It looks like this is
either a leaked descriptor or xauth output was redirected to a file it is not
allowed to access. Leaks usually can be ignored since SELinux is just closing
the leak and reporting the error. The application does not use the descriptor,
so it will run properly. If this is a redirection, you will not get output in
the unix_stream_socket. You should generate a bugzilla on selinux-policy, and it
will get routed to the appropriate package. You can safely ignore this avc.

Allowing Access:

You can generate a local policy module to allow this access - see FAQ
(http://fedora.redhat.com/docs/selinux-faq-fc5/#id2961385)

Additional Information:

Source Context                unconfined_u:unconfined_r:xauth_t:s0-s0:c0.c1023
Target Context                unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1
                              023
Target Objects                unix_stream_socket [ unix_stream_socket ]
Source                        xauth
Source Path                   /usr/bin/xauth
Port                          <Unknown>
Host                          (removed)
Source RPM Packages           xorg-x11-xauth-1.0.2-7.fc12
Target RPM Packages           
Policy RPM                    selinux-policy-3.6.32-35.fc12
Selinux Enabled               True
Policy Type                   targeted
MLS Enabled                   True
Enforcing Mode                Enforcing
Plugin Name                   leaks
Host Name                     (removed)
Platform                      Linux (removed) 2.6.31.5-96.fc12.x86_64 #1 SMP Fri
                              Oct 23 19:30:30 EDT 2009 x86_64 x86_64
Alert Count                   2
First Seen                    Thu 29 Oct 2009 10:11:28 AM CET
Last Seen                     Thu 29 Oct 2009 12:34:34 PM CET
Local ID                      12224606-ab27-4d68-b5b4-661b6e18f24b
Line Numbers                  

Raw Audit Messages            

node=(removed) type=AVC msg=audit(1256816074.22:55): avc:  denied  { read write } for  pid=18514 comm="xauth" path="socket:[236140]" dev=sockfs ino=236140 scontext=unconfined_u:unconfined_r:xauth_t:s0-s0:c0.c1023 tcontext=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 tclass=unix_stream_socket

node=(removed) type=SYSCALL msg=audit(1256816074.22:55): arch=c000003e syscall=59 success=yes exit=0 a0=1104f20 a1=1105160 a2=1103300 a3=20 items=0 ppid=18513 pid=18514 auid=500 uid=500 gid=500 euid=500 suid=500 fsuid=500 egid=500 sgid=500 fsgid=500 tty=pts0 ses=1 comm="xauth" exe="/usr/bin/xauth" subj=unconfined_u:unconfined_r:xauth_t:s0-s0:c0.c1023 key=(null)



Hash String generated from  selinux-policy-3.6.32-35.fc12,leaks,xauth,xauth_t,unconfined_t,unix_stream_socket,read,write
audit2allow suggests:

#============= xauth_t ==============
allow xauth_t unconfined_t:unix_stream_socket { read write };

Comment 1 Ruben Vermeersch 2009-10-29 11:39:57 UTC
Happens when starting an X forwarded application over SSH.

Comment 2 Daniel Walsh 2009-10-29 12:27:49 UTC
Not sure who is leaking, but will dontaudit.

Fixed in selinux-policy-3.6.32-36.fc12.noarch

Comment 3 Jim Meyering 2009-11-02 09:17:35 UTC
FYI, reproducible when running "f12$ ssh -f rawhide xmessage foo" from an F12 to a rawhide system.  I've updated the rawhide system to selinux-policy*-3.6.32-38.fc12.noarch and now it works fine.  Actually updated first the F12 system (pretty sure I noticed that that didn't help), then updated the rawhide one, and that solved it.

Comment 4 Michal Hlavinka 2009-11-03 20:21:45 UTC
I can reproduce this bug with selinux-policy*-3.6.32-40.fc12:


Summary:

SELinux is preventing /usr/bin/xauth access to a leaked unix_stream_socket file
descriptor.

Additional Information:

Source Context                unconfined_u:unconfined_r:xauth_t:s0-s0:c0.c1023
Target Context                unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1
                              023
Target Objects                unix_stream_socket [ unix_stream_socket ]
Source                        xauth
Source Path                   /usr/bin/xauth
Port                          <Unknown>
Host                          localhost.localdomain
Source RPM Packages           xorg-x11-xauth-1.0.2-7.fc12
Target RPM Packages           
Policy RPM                    selinux-policy-3.6.32-40.fc12
Selinux Enabled               True
Policy Type                   targeted
MLS Enabled                   True
Enforcing Mode                Enforcing
Plugin Name                   leaks
Host Name                     localhost.localdomain
Platform                      Linux localhost.localdomain
                              2.6.31.5-112.fc12.x86_64 #1
                              SMP Tue Nov 3 00:28:52 EST 2009 x86_64 x86_64
Alert Count                   6
First Seen                    Tue 03 Nov 2009 08:37:03 PM CET
Last Seen                     Tue 03 Nov 2009 08:48:03 PM CET
Local ID                      44af8602-3068-4b79-96a9-7e49e33ba886
Line Numbers                  

Raw Audit Messages            

node=localhost.localdomain type=AVC msg=audit(1257277683.686:23302): avc:  denied  { read write } for  pid=2602 comm="xauth" path="socket:[87877]" dev=sockfs ino=87877 scontext=unconfined_u:unconfined_r:xauth_t:s0-s0:c0.c1023 tcontext=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 tclass=unix_stream_socket

node=localhost.localdomain type=SYSCALL msg=audit(1257277683.686:23302): arch=c000003e syscall=59 success=yes exit=0 a0=7fff4b421191 a1=12aed60 a2=1260be0 a3=389cc82560 items=0 ppid=2593 pid=2602 auid=500 uid=500 gid=500 euid=500 suid=500 fsuid=500 egid=500 sgid=500 fsgid=500 tty=(none) ses=1 comm="xauth" exe="/usr/bin/xauth" subj=unconfined_u:unconfined_r:xauth_t:s0-s0:c0.c1023 key=(null)

Comment 5 Daniel Walsh 2009-11-04 13:33:22 UTC
Fixed in selinux-policy-3.6.32-41.fc12.noarch
My fix had a bug in it sorry.