Description of problem:
SELinux is preventing /opt/google/chrome/nacl_helper_bootstrap from 'append' accesses on the file /home/francisco/.config/mailnag/mailnag.log.

*****  Plugin leaks (86.2 confidence) suggests  ******************************

If you want to ignore nacl_helper_bootstrap trying to append access the mailnag.log file, because you believe it should not need this access.
Then you should report this as a bug.  
You can generate a local policy module to dontaudit this access.
Do
# grep /opt/google/chrome/nacl_helper_bootstrap /var/log/audit/audit.log | audit2allow -D -M mypol
# semodule -i mypol.pp

*****  Plugin catchall (14.7 confidence) suggests  ***************************

If you believe that nacl_helper_bootstrap should be allowed append access on the mailnag.log 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                unconfined_u:object_r:config_home_t:s0
Target Objects                /home/francisco/.config/mailnag/mailnag.log [ file
                              ]
Source                        nacl_helper_boo
Source Path                   /opt/google/chrome/nacl_helper_bootstrap
Port                          <Unknown>
Host                          (removed)
Source RPM Packages           google-chrome-unstable-25.0.1364.5-174090.x86_64
Target RPM Packages           
Policy RPM                    selinux-policy-3.11.1-67.fc18.noarch
Selinux Enabled               True
Policy Type                   targeted
Enforcing Mode                Enforcing
Host Name                     (removed)
Platform                      Linux (removed) 3.6.11-3.fc18.x86_64 #1 SMP Mon
                              Dec 17 21:35:39 UTC 2012 x86_64 x86_64
Alert Count                   1
First Seen                    2013-01-07 04:53:19 AST
Last Seen                     2013-01-07 04:53:19 AST
Local ID                      64e50b14-7a8d-4012-945a-0a421fe593c9

Raw Audit Messages
type=AVC msg=audit(1357548799.131:674): avc:  denied  { append } for  pid=13371 comm="nacl_helper_boo" path="/home/francisco/.config/mailnag/mailnag.log" dev="dm-3" ino=9701040 scontext=unconfined_u:unconfined_r:chrome_sandbox_nacl_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:config_home_t:s0 tclass=file


type=AVC msg=audit(1357548799.131:674): avc:  denied  { append } for  pid=13371 comm="nacl_helper_boo" path="/home/francisco/.config/mailnag/mailnag.log" dev="dm-3" ino=9701040 scontext=unconfined_u:unconfined_r:chrome_sandbox_nacl_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:config_home_t:s0 tclass=file


type=SYSCALL msg=audit(1357548799.131:674): arch=x86_64 syscall=execve success=yes exit=0 a0=7f8c94ea3e78 a1=7f8c94e939f0 a2=7fff82a1f9d0 a3=7f8c88b8d040 items=0 ppid=1 pid=13371 auid=1000 uid=1000 gid=1000 euid=1000 suid=1000 fsuid=1000 egid=1000 sgid=1000 fsgid=1000 tty=(none) ses=2 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,config_home_t,file,append

audit2allow

#============= chrome_sandbox_nacl_t ==============
allow chrome_sandbox_nacl_t config_home_t:file append;

audit2allow -R

#============= chrome_sandbox_nacl_t ==============
allow chrome_sandbox_nacl_t config_home_t:file append;


Additional info:
hashmarkername: setroubleshoot
kernel:         3.6.11-3.fc18.x86_64
type:           libreport