Bug 542170

Summary:

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

Detailed Description:

The liferea 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 liferea 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 liferea to
run correctly, you can change the context of the executable to execmem_exec_t.
"chcon -t execmem_exec_t '/usr/bin/liferea'" 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/liferea'"

Fix Command:

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

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                        liferea
Source Path                   /usr/bin/liferea
Port                          <Unknown>
Host                          (removed)
Source RPM Packages           liferea-1.6.0-1.fc12
Target RPM Packages           
Policy RPM                    selinux-policy-3.6.32-46.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.i686 #1
                              SMP Sat Nov 7 21:41:45 EST 2009 i686 i686
Alert Count                   1
First Seen                    Sat 28 Nov 2009 05:46:58 PM CET
Last Seen                     Sat 28 Nov 2009 05:46:58 PM CET
Local ID                      cf800d05-de33-4cbe-a54a-227263a22ac3
Line Numbers                  

Raw Audit Messages            

node=(removed) type=AVC msg=audit(1259426818.979:135): avc:  denied  { execstack } for  pid=1685 comm="liferea" 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(1259426818.979:135): arch=40000003 syscall=125 success=no exit=-13 a0=bfc19000 a1=1000 a2=1000007 a3=bfc16fe0 items=0 ppid=1558 pid=1685 auid=500 uid=500 gid=500 euid=500 suid=500 fsuid=500 egid=500 sgid=500 fsgid=500 tty=(none) ses=1 comm="liferea" exe="/usr/bin/liferea" subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)



Hash String generated from  selinux-policy-3.6.32-46.fc12,allow_execstack,liferea,unconfined_t,unconfined_t,process,execstack
audit2allow suggests:

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