SELinux is preventing /usr/bin/mencoder from using the 'execstack' accesses on a process.

*****  Plugin allow_execstack (53.1 confidence) suggests  ********************

If you do not think /usr/bin/mencoder should need to map stack memory that is both writable and executable.
Then you need to report a bug. This is a potentially dangerous access.
Do
contact your security administrator and report this issue.

*****  Plugin catchall_boolean (42.6 confidence) suggests  *******************

If you want to allow unconfined executables to make their stack executable.  This should never, ever be necessary. Probably indicates a badly coded executable, but could indicate an attack. This executable should be reported in bugzilla
Then you must tell SELinux about this by enabling the 'allow_execstack' boolean.
Do
setsebool -P allow_execstack 1

*****  Plugin catchall (5.76 confidence) suggests  ***************************

If you believe that mencoder should be allowed execstack access on processes labeled unconfined_t by default.
Then you should report this as a bug.
You can generate a local policy module to allow this access.
Do
allow this access for now by executing:
# grep /usr/bin/mencoder /var/log/audit/audit.log | audit2allow -M mypol
# semodule -i mypol.pp

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                Unknown [ process ]
Source                        mencoder
Source Path                   /usr/bin/mencoder
Port                          <Sconosciuto>
Host                          (removed)
Source RPM Packages           mencoder-1.0-0.119.20100703svn.fc14
Target RPM Packages           
Policy RPM                    selinux-policy-3.9.7-19.fc14
Selinux Enabled               True
Policy Type                   targeted
Enforcing Mode                Enforcing
Host Name                     (removed)
Platform                      Linux (removed) 2.6.35.10-74.fc14.i686 #1 SMP Thu Dec
                              23 16:17:40 UTC 2010 i686 i686
Alert Count                   1
First Seen                    mer 29 dic 2010 16:08:39 CET
Last Seen                     mer 29 dic 2010 16:08:39 CET
Local ID                      ce80936c-3346-4f3d-807e-8aee2ba31594

Raw Audit Messages
type=AVC msg=audit(1293635319.835:17592): avc:  denied  { execstack } for  pid=3363 comm="mencoder" scontext=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 tcontext=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 tclass=process

mencoder,unconfined_t,unconfined_t,process,execstack
type=SYSCALL msg=audit(1293635319.835:17592): arch=i386 syscall=mprotect success=no exit=EACCES a0=bfe76000 a1=1000 a2=1000007 a3=bfe76620 items=0 ppid=2939 pid=3363 auid=500 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts0 ses=1 comm=mencoder exe=/usr/bin/mencoder subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)
mencoder,unconfined_t,unconfined_t,process,execstack

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

allow unconfined_t self:process execstack;