Description of problem:
I opened google chrome and saw this issue. 
SELinux is preventing /opt/google/chrome/nacl_helper_bootstrap from 'execute' accesses on the chr_file /dev/zero.

*****  Plugin catchall (100. confidence) suggests  ***************************

If you believe that nacl_helper_bootstrap should be allowed execute access on the zero chr_file 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 nacl_helper_boo /var/log/audit/audit.log | audit2allow -M mypol
# semodule -i mypol.pp

Additional Information:
Source Context                unconfined_u:unconfined_r:chrome_sandbox_nacl_t:s0
                              -s0:c0.c1023
Target Context                system_u:object_r:zero_device_t:s0
Target Objects                /dev/zero [ chr_file ]
Source                        nacl_helper_boo
Source Path                   /opt/google/chrome/nacl_helper_bootstrap
Port                          <Unknown>
Host                          (removed)
Source RPM Packages           google-chrome-stable-24.0.1312.70-181759.i386
Target RPM Packages           
Policy RPM                    selinux-policy-3.11.1-76.fc18.noarch
Selinux Enabled               True
Policy Type                   targeted
Enforcing Mode                Permissive
Host Name                     (removed)
Platform                      Linux (removed) 3.7.6-201.fc18.i686.PAE #1 SMP Mon
                              Feb 4 16:05:44 UTC 2013 i686 i686
Alert Count                   1
First Seen                    2013-02-13 23:48:30 IST
Last Seen                     2013-02-13 23:48:30 IST
Local ID                      6bea7d83-82d8-4456-9319-89794cd949a3

Raw Audit Messages
type=AVC msg=audit(1360779510.757:376): avc:  denied  { execute } for  pid=2848 comm="nacl_helper_boo" path="/dev/zero" dev="devtmpfs" ino=22 scontext=unconfined_u:unconfined_r:chrome_sandbox_nacl_t:s0-s0:c0.c1023 tcontext=system_u:object_r:zero_device_t:s0 tclass=chr_file


type=SYSCALL msg=audit(1360779510.757:376): arch=i386 syscall=mmap2 success=yes exit=-1218199552 a0=0 a1=2000 a2=7 a3=2 items=0 ppid=1 pid=2848 auid=1000 uid=1000 gid=1000 euid=1000 suid=1000 fsuid=1000 egid=1000 sgid=1000 fsgid=1000 ses=2 tty=(none) comm=nacl_helper_boo exe=/opt/google/chrome/nacl_helper_bootstrap subj=unconfined_u:unconfined_r:chrome_sandbox_nacl_t:s0-s0:c0.c1023 key=(null)

Hash: nacl_helper_boo,chrome_sandbox_nacl_t,zero_device_t,chr_file,execute

audit2allow

#============= chrome_sandbox_nacl_t ==============
allow chrome_sandbox_nacl_t zero_device_t:chr_file execute;

audit2allow -R

#============= chrome_sandbox_nacl_t ==============
allow chrome_sandbox_nacl_t zero_device_t:chr_file execute;


Additional info:
hashmarkername: setroubleshoot
kernel:         3.7.6-201.fc18.i686.PAE
type:           libreport