Bug 655362

Summary:

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

Detailed Description:

The gscan2pdf 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://www.akkadia.org/drepper/selinux-mem.html) web page explains how to
remove this requirement. If gscan2pdf 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 gscan2pdf
to run correctly, you can change the context of the executable to
execmem_exec_t. "chcon -t execmem_exec_t '/usr/bin/perl'" 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/perl'"

Fix Command:

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

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                        gscan2pdf
Source Path                   /usr/bin/perl
Port                          <Unknown>
Host                          (removed)
Source RPM Packages           perl-5.12.2-136.fc14
Target RPM Packages           
Policy RPM                    selinux-policy-3.9.7-10.fc14
Selinux Enabled               True
Policy Type                   targeted
Enforcing Mode                Enforcing
Plugin Name                   allow_execstack
Host Name                     (removed)
Platform                      Linux (removed)
                              2.6.35.6-48.fc14.i686.PAE #1 SMP Fri Oct 22
                              15:27:53 UTC 2010 i686 i686
Alert Count                   1
First Seen                    Sat 20 Nov 2010 17:41:07 GMT
Last Seen                     Sat 20 Nov 2010 17:41:07 GMT
Local ID                      45f2ab77-5c8b-4361-bc64-9994269c0a2f
Line Numbers                  

Raw Audit Messages            

node=(removed) type=AVC msg=audit(1290274867.38:45205): avc:  denied  { execstack } for  pid=3308 comm="gscan2pdf" 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(1290274867.38:45205): arch=40000003 syscall=125 success=no exit=-13 a0=bf99c000 a1=1000 a2=1000007 a3=bf99b730 items=0 ppid=3306 pid=3308 auid=500 uid=500 gid=500 euid=500 suid=500 fsuid=500 egid=500 sgid=500 fsgid=500 tty=(none) ses=1 comm="gscan2pdf" exe="/usr/bin/perl" subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)



Hash String generated from  allow_execstack,gscan2pdf,unconfined_t,unconfined_t,process,execstack
audit2allow suggests:

#============= unconfined_t ==============
#!!!! This avc can be allowed using the boolean 'allow_execstack'

allow unconfined_t self:process execstack;