Bug 250907 - SELinux is preventing /usr/sbin/in.ntalkd (ktalkd_t) "search" to / (devpts_t).
SELinux is preventing /usr/sbin/in.ntalkd (ktalkd_t) "search" to / (devpts_t).
Product: Fedora
Classification: Fedora
Component: selinux-policy (Show other bugs)
x86_64 Linux
low Severity medium
: ---
: ---
Assigned To: Miroslav Grepl
Fedora Extras Quality Assurance
: Reopened
Depends On:
  Show dependency treegraph
Reported: 2007-08-04 19:57 EDT by Jacob Masaki
Modified: 2009-11-18 05:29 EST (History)
2 users (show)

See Also:
Fixed In Version: Current
Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
Last Closed: 2009-11-18 05:29:54 EST
Type: ---
Regression: ---
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Documentation: ---
Verified Versions:
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oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

Attachments (Terms of Use)
Output from selinux troubleshooter. (2.31 KB, text/plain)
2007-08-04 19:59 EDT, Jacob Masaki
no flags Details

  None (edit)
Description Jacob Masaki 2007-08-04 19:57:44 EDT
From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv: Gecko/20070718 Fedora/ Firefox/

Description of problem:
When I run talk on my local machine (to another local terminal) it replies with "Target machine is too confused to talk to us" and SELinux troubleschooter pops up with a denial.

With SELinux set to permissive everything works fine.  

Version-Release number of selected component (if applicable):
talk-server-0.17-29.2.2, selinux-policy-2.6.4-30.fc7, selinux-policy-targeted-2.6.4-30.fc7

How reproducible:

Steps to Reproduce:
1. Install talk-server
2. Activate and start xinetd through system-config-services
3. Activate talk and ntalk under the "on demand services" tab
4. Run "talk" from one local terminal to another ("who am i" gives the info you need to choose proper arguments.

Actual Results:
Talk displays "Target machine is too confused to talk to us" then tries to connect until it is killed.  

Expected Results:
Talk should have connected the two terminals so they can send messages back and forth.  

Additional info:
Comment 1 Jacob Masaki 2007-08-04 19:59:07 EDT
Created attachment 160704 [details]
Output from selinux troubleshooter.
Comment 2 Daniel Walsh 2007-09-04 09:23:49 EDT
Fixed in selinux-policy-2.6.4-41
Comment 3 Daniel Walsh 2008-01-30 14:19:42 EST
Bulk closing all bugs in Fedora updates in the modified state.  If you bug is
not fixed, please reopen.
Comment 4 Gregory Maxwell 2009-02-20 23:26:14 EST
Problem seems to be back, ntalk is incorrectly telling me that the other party is refusing messages. 

[root@cherenkov gmaxwell]#  sealert -l b99d40e7-3aba-4703-9dea-b2df3d8b905a


SELinux prevented in.ntalkd from using the terminal 4.

Detailed Description:

SELinux prevented in.ntalkd from using the terminal 4. In most cases daemons do
not need to interact with the terminal, usually these avc messages can be
ignored. All of the confined daemons should have dontaudit rules around using
the terminal. Please file a bug report
(http://bugzilla.redhat.com/bugzilla/enter_bug.cgi) against this selinux-policy.
If you would like to allow all daemons to interact with the terminal, you can
turn on the allow_daemons_use_tty boolean.

Allowing Access:

Changing the "allow_daemons_use_tty" boolean to true will allow this access:
"setsebool -P allow_daemons_use_tty=1."

Fix Command:

setsebool -P allow_daemons_use_tty=1

Additional Information:

Source Context                unconfined_u:system_r:ktalkd_t:s0-s0:c0.c1023
Target Context                unconfined_u:object_r:unconfined_devpts_t:s0
Target Objects                4 [ chr_file ]
Source                        in.ntalkd
Source Path                   /usr/sbin/in.ntalkd
Port                          <Unknown>
Host                          cherenkov
Source RPM Packages           talk-server-0.17-30.2.4
Target RPM Packages           
Policy RPM                    selinux-policy-3.5.13-45.fc10
Selinux Enabled               True
Policy Type                   targeted
MLS Enabled                   True
Enforcing Mode                Enforcing
Plugin Name                   allow_daemons_use_tty
Host Name                     cherenkov
Platform                      Linux cherenkov #1
                              SMP Wed Jan 21 01:33:24 EST 2009 x86_64 x86_64
Alert Count                   5
First Seen                    Fri Feb 20 23:16:01 2009
Last Seen                     Fri Feb 20 23:22:44 2009
Local ID                      b99d40e7-3aba-4703-9dea-b2df3d8b905a
Line Numbers                  

Raw Audit Messages            

node=cherenkov type=AVC msg=audit(1235190164.503:7176): avc:  denied  { write } for  pid=17203 comm="in.ntalkd" name="4" dev=devpts ino=6 scontext=unconfined_u:system_r:ktalkd_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:unconfined_devpts_t:s0 tclass=chr_file

node=cherenkov type=SYSCALL msg=audit(1235190164.503:7176): arch=c000003e syscall=2 success=no exit=-13 a0=7fffada46470 a1=101 a2=b a3=7fffada45c10 items=0 ppid=17198 pid=17203 auid=500 uid=99 gid=5 euid=99 suid=99 fsuid=99 egid=5 sgid=5 fsgid=5 tty=(none) ses=1073 comm="in.ntalkd" exe="/usr/sbin/in.ntalkd" subj=unconfined_u:system_r:ktalkd_t:s0-s0:c0.c1023 key=(null)

[root@cherenkov gmaxwell]# getsebool allow_daemons_use_tty
allow_daemons_use_tty --> on
[root@cherenkov gmaxwell]# cat /etc/redhat-release 
Fedora release 10 (Cambridge)
[root@cherenkov gmaxwell]# uname -a
Linux cherenkov #1 SMP Wed Jan 21 01:33:24 EST 2009 x86_64 x86_64 x86_64 GNU/Linux
[root@cherenkov gmaxwell]# rpm -q selinux-policy
Comment 5 Daniel Walsh 2009-02-23 10:05:58 EST



ktalk needs to write to terminals.
Comment 6 Miroslav Grepl 2009-02-27 04:51:06 EST
Fixed in selinux-policy-3.5.13-47.fc10
Comment 7 Bug Zapper 2009-11-18 05:07:25 EST
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