SELinux is preventing /usr/lib64/firefox-4.0/firefox-bin from using the 'execstack' accesses on a process.

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

If you do not think /usr/lib64/firefox-4.0/firefox-bin 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 firefox-bin 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 firefox-bin /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                        firefox-bin
Source Path                   /usr/lib64/firefox-4.0/firefox-bin
Port                          <Unknown>
Host                          (removed)
Source RPM Packages           firefox4-4.0-0.17.beta9.fc14.remi
Target RPM Packages           
Policy RPM                    selinux-policy-3.9.7-20.fc14
Selinux Enabled               True
Policy Type                   targeted
Enforcing Mode                Permissive
Host Name                     (removed)
Platform                      Linux (removed) 2.6.35.10-77.fc14.x86_64 #1 SMP
                              Mon Jan 10 22:44:54 UTC 2011 x86_64 x86_64
Alert Count                   2
First Seen                    Fri 14 Jan 2011 12:10:09 PM PST
Last Seen                     Fri 14 Jan 2011 12:12:48 PM PST
Local ID                      544cc51d-baa1-4ab3-b3a9-b7329022fc27

Raw Audit Messages
type=AVC msg=audit(1295035968.902:19648): avc:  denied  { execstack } for  pid=9225 comm="firefox-bin" scontext=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 tcontext=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 tclass=process

firefox-bin,unconfined_t,unconfined_t,process,execstack
type=SYSCALL msg=audit(1295035968.902:19648): arch=x86_64 syscall=mprotect success=yes exit=0 a0=7ffff8b76000 a1=1000 a2=1000007 a3=37b5021000 items=0 ppid=1 pid=9225 auid=500 uid=500 gid=500 euid=500 suid=500 fsuid=500 egid=500 sgid=500 fsgid=500 tty=(none) ses=1 comm=firefox-bin exe=/usr/lib64/firefox-4.0/firefox-bin subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)
firefox-bin,unconfined_t,unconfined_t,process,execstack

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

allow unconfined_t self:process execstack;