Bug 539799

Summary:

SELinux is preventing /usr/bin/compiz from making the program stack executable.

Detailed Description:

[compiz has a permissive type (unconfined_t). This access was not denied.]

The compiz application attempted to make its stack executable. This is a
potential security problem. This should never ever be necessary. Stack memory is
not executable on most OSes these days and this will not change. Executable
stack memory is one of the biggest security problems. An execstack error might
in fact be most likely raised by malicious code. Applications are sometimes
coded incorrectly and request this permission. The SELinux Memory Protection
Tests (http://people.redhat.com/drepper/selinux-mem.html) web page explains how
to remove this requirement. If compiz does not work and you need it to work, you
can configure SELinux temporarily to allow this access until the application is
fixed. Please file a bug report.

Allowing Access:

Sometimes a library is accidentally marked with the execstack flag, if you find
a library with this flag you can clear it with the execstack -c LIBRARY_PATH.
Then retry your application. If the app continues to not work, you can turn the
flag back on with execstack -s LIBRARY_PATH. Otherwise, if you trust compiz to
run correctly, you can change the context of the executable to execmem_exec_t.
"chcon -t execmem_exec_t '/usr/bin/compiz'" You must also change the default
file context files on the system in order to preserve them even on a full
relabel. "semanage fcontext -a -t execmem_exec_t '/usr/bin/compiz'"

Fix Command:

chcon -t execmem_exec_t '/usr/bin/compiz'

Additional Information:

Source Context                unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1
                              023
Target Context                unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1
                              023
Target Objects                None [ process ]
Source                        compiz
Source Path                   /usr/bin/compiz
Port                          <Unknown>
Host                          (removed)
Source RPM Packages           compiz-0.8.2-19.fc12
Target RPM Packages           
Policy RPM                    selinux-policy-3.6.32-41.fc12
Selinux Enabled               True
Policy Type                   targeted
Enforcing Mode                Enforcing
Plugin Name                   allow_execstack
Host Name                     (removed)
Platform                      Linux (removed) 2.6.31.5-127.fc12.x86_64 #1 SMP Sat
                              Nov 7 21:11:14 EST 2009 x86_64 x86_64
Alert Count                   4
First Seen                    Sat 21 Nov 2009 01:15:56 PM EST
Last Seen                     Sat 21 Nov 2009 02:00:16 PM EST
Local ID                      4adcf562-18e2-4b5e-ad98-1cfecea0c5b5
Line Numbers                  

Raw Audit Messages            

node=(removed) type=AVC msg=audit(1258776016.338:36704): avc:  denied  { execstack } for  pid=3306 comm="compiz" scontext=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 tcontext=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 tclass=process

node=(removed) type=SYSCALL msg=audit(1258776016.338:36704): arch=c000003e syscall=10 success=yes exit=128 a0=7fff09865000 a1=1000 a2=1000007 a3=7f55f478eaeb items=0 ppid=2015 pid=3306 auid=500 uid=500 gid=500 euid=500 suid=500 fsuid=500 egid=500 sgid=500 fsgid=500 tty=(none) ses=1 comm="compiz" exe="/usr/bin/compiz" subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)



Hash String generated from  selinux-policy-3.6.32-41.fc12,allow_execstack,compiz,unconfined_t,unconfined_t,process,execstack
audit2allow suggests:

#============= unconfined_t ==============
allow unconfined_t self:process execstack;