Description of problem:
SELinux is preventing /usr/bin/gnome-shell from 'read' accesses on the file /opt/VirtualBox/virtualbox.desktop.

*****  Plugin restorecon (94.8 confidence) suggests  *************************

If you want to fix the label. 
/opt/VirtualBox/virtualbox.desktop default label should be usr_t.
Then you can run restorecon.
Do
# /sbin/restorecon -v /opt/VirtualBox/virtualbox.desktop

*****  Plugin catchall_labels (5.21 confidence) suggests  ********************

If you want to allow gnome-shell to have read access on the virtualbox.desktop file
Then you need to change the label on /opt/VirtualBox/virtualbox.desktop
Do
# semanage fcontext -a -t FILE_TYPE '/opt/VirtualBox/virtualbox.desktop'
where FILE_TYPE is one of the following: NetworkManager_etc_rw_t, NetworkManager_etc_t, NetworkManager_tmp_t, abrt_etc_t, abrt_helper_exec_t, abrt_tmp_t, abrt_var_cache_t, abrt_var_run_t, accountsd_var_lib_t, admin_crontab_tmp_t, afs_cache_t, aiccu_etc_t, aisexec_tmp_t, alsa_etc_rw_t, alsa_exec_t, alsa_home_t, alsa_tmp_t, amanda_tmp_t, amavis_etc_t, amavis_tmp_t, anon_inodefs_t, apcupsd_tmp_t, apmd_tmp_t, arpwatch_tmp_t, asterisk_etc_t, asterisk_tmp_t, audio_home_t, auditadm_sudo_tmp_t, auth_cache_t, auth_home_t, automount_tmp_t, awstats_tmp_t, bin_t, bitlbee_conf_t, bitlbee_tmp_t, bluetooth_conf_t, bluetooth_helper_tmp_t, bluetooth_tmp_t, boinc_project_tmp_t, boinc_tmp_t, boot_t, bootloader_etc_t, bootloader_tmp_t, cache_home_t, cardmgr_dev_t, ccs_tmp_t, cdcc_tmp_t, cert_t, cgconfig_etc_t, cgroup_t, cgrules_etc_t, chkpwd_exec_t, chrome_sandbox_tmp_t, clamd_etc_t, clamd_tmp_t, clamscan_tmp_t, cluster_conf_t, cobbler_etc_t, cobbler_tmp_t, colord_tmp_t, comsat_tmp_t, condor_master_tmp_t, condor_schedd_tmp_t, condor_startd_tmp_t, config_home_t, config_usr_t, consolekit_log_t, corosync_tmp_t, couchdb_etc_t, couchdb_tmp_t, courier_etc_t, cpu_online_t, cpucontrol_conf_t, crack_db_t, crack_tmp_t, crond_tmp_t, crontab_tmp_t, ctdbd_tmp_t, cups_pdf_tmp_t, cupsd_etc_t, cupsd_lpd_tmp_t, cupsd_rw_etc_t, cupsd_tmp_t, cvs_tmp_t, cyphesis_tmp_t, cyrus_tmp_t, data_home_t, dbadm_sudo_tmp_t, dbskkd_tmp_t, dbus_home_t, dbusd_etc_t, dbusd_exec_t, dcc_client_tmp_t, dcc_dbclean_tmp_t, dccd_tmp_t, dccifd_tmp_t, dccm_tmp_t, ddclient_etc_t, ddclient_tmp_t, default_context_t, deltacloudd_tmp_t, devicekit_tmp_t, dhcp_etc_t, dhcpc_tmp_t, dhcpd_tmp_t, dictd_etc_t, dirsrv_tmp_t, dirsrvadmin_tmp_t, disk_munin_plugin_tmp_t, dnsmasq_etc_t, dovecot_auth_tmp_t, dovecot_deliver_tmp_t, dovecot_etc_t, dovecot_tmp_t, dspam_tmp_t, ecryptfs_t, etc_mail_t, etc_runtime_t, etc_t, exim_tmp_t, exports_t, fail2ban_tmp_t, faillog_t, fenced_tmp_t, fetchmail_etc_t, fetchmail_home_t, file_context_t, fingerd_etc_t, firewalld_etc_rw_t, firewalld_tmp_t, firewallgui_tmp_t, firstboot_etc_t, fonts_cache_t, fonts_t, fsadm_tmp_t, fsdaemon_tmp_t, ftpd_etc_t, ftpd_tmp_t, ftpdctl_tmp_t, fusermount_exec_t, games_tmp_t, gconf_etc_t, gconf_home_t, gconf_tmp_t, getty_etc_t, getty_tmp_t, git_user_content_t, gkeyringd_exec_t, gkeyringd_gnome_home_t, gkeyringd_tmp_t, glance_registry_tmp_t, glance_tmp_t, glusterd_tmp_t, gnome_home_t, gpg_agent_tmp_t, gpg_pinentry_tmp_t, gpg_secret_t, gpm_conf_t, gpm_tmp_t, gssd_tmp_t, gstreamer_home_t, hddtemp_etc_t, home_bin_t, home_cert_t, hostname_etc_t, hostname_exec_t, httpd_bugzilla_tmp_t, httpd_collectd_script_tmp_t, httpd_config_t, httpd_mojomojo_tmp_t, httpd_munin_script_tmp_t, httpd_php_tmp_t, httpd_suexec_tmp_t, httpd_tmp_t, httpd_user_content_t, httpd_user_htaccess_t, httpd_user_ra_content_t, httpd_user_rw_content_t, httpd_user_script_exec_t, httpd_w3c_validator_tmp_t, hwdata_t, icc_data_home_t, iceauth_home_t, inetd_child_tmp_t, inetd_tmp_t, init_exec_t, initrc_tmp_t, initrc_var_run_t, innd_etc_t, ipsec_tmp_t, iptables_tmp_t, irc_home_t, irc_tmp_t, irssi_etc_t, irssi_home_t, iscsi_tmp_t, kadmind_tmp_t, kdump_etc_t, kdumpctl_tmp_t, kdumpgui_tmp_t, keystone_tmp_t, kismet_home_t, kismet_tmp_t, kismet_tmpfs_t, klogd_tmp_t, krb5_conf_t, krb5_home_t, krb5_host_rcache_t, krb5_keytab_t, krb5kdc_conf_t, krb5kdc_tmp_t, ktalkd_tmp_t, l2tp_etc_t, l2tpd_tmp_t, lastlog_t, ld_so_cache_t, ld_so_t, ldconfig_exec_t, ldconfig_tmp_t, lib_t, likewise_etc_t, lircd_etc_t, livecd_tmp_t, loadkeys_exec_t, local_login_home_t, locale_t, logrotate_mail_tmp_t, logrotate_tmp_t, logwatch_mail_tmp_t, logwatch_tmp_t, lpd_tmp_t, lpr_tmp_t, lsassd_tmp_t, lvm_etc_t, lvm_tmp_t, machineid_t, mail_home_rw_t, mail_home_t, mail_munin_plugin_tmp_t, mailman_cgi_tmp_t, mailman_mail_tmp_t, mailman_queue_tmp_t, man_t, mandb_cache_t, mock_etc_t, mock_tmp_t, modules_conf_t, mongod_tmp_t, mount_ecryptfs_exec_t, mount_exec_t, mount_tmp_t, mozilla_conf_t, mozilla_home_t, mozilla_plugin_tmp_t, mozilla_plugin_tmpfs_t, mozilla_tmp_t, mpd_etc_t, mpd_tmp_t, mpd_user_data_t, mplayer_etc_t, mplayer_home_t, mrtg_etc_t, mscan_etc_t, mscan_tmp_t, munin_etc_t, munin_tmp_t, mysqld_etc_t, mysqld_home_t, mysqld_tmp_t, nagios_etc_t, nagios_eventhandler_plugin_tmp_t, nagios_system_plugin_tmp_t, nagios_tmp_t, named_conf_t, named_tmp_t, net_conf_t, netutils_tmp_t, nova_ajax_tmp_t, nova_api_tmp_t, nova_cert_tmp_t, nova_compute_tmp_t, nova_console_tmp_t, nova_direct_tmp_t, nova_network_tmp_t, nova_objectstore_tmp_t, nova_scheduler_tmp_t, nova_vncproxy_tmp_t, nova_volume_tmp_t, nrpe_etc_t, nslcd_conf_t, ntop_etc_t, ntop_tmp_t, ntpd_tmp_t, nut_conf_t, nx_server_tmp_t, oddjob_mkhomedir_exec_t, openct_var_run_t, openshift_cgroup_read_tmp_t, openshift_cron_tmp_t, openshift_initrc_tmp_t, openshift_tmp_t, openvpn_etc_rw_t, openvpn_etc_t, openvpn_tmp_t, openvswitch_rw_t, pacemaker_tmp_t, pads_config_t, pam_console_exec_t, pam_timestamp_exec_t, pam_timestamp_tmp_t, pam_var_console_t, pam_var_run_t, passenger_tmp_t, passwd_file_t, pcscd_var_run_t, pegasus_conf_t, pegasus_tmp_t, pingd_etc_t, piranha_etc_rw_t, piranha_web_conf_t, piranha_web_tmp_t, pkcsslotd_tmp_t, pki_tomcat_tmp_t, plymouth_exec_t, plymouthd_var_log_t, podsleuth_tmp_t, policykit_auth_exec_t, policykit_reload_t, policykit_tmp_t, policykit_var_lib_t, polipo_cache_home_t, polipo_config_home_t, polipo_etc_t, portmap_tmp_t, portreserve_etc_t, postfix_bounce_tmp_t, postfix_cleanup_tmp_t, postfix_etc_t, postfix_local_tmp_t, postfix_map_tmp_t, postfix_pickup_tmp_t, postfix_pipe_tmp_t, postfix_qmgr_tmp_t, postfix_smtp_tmp_t, postfix_smtpd_tmp_t, postfix_virtual_tmp_t, postgresql_etc_t, postgresql_tmp_t, postgrey_etc_t, power_unit_file_t, pppd_etc_t, pppd_tmp_t, prelink_exec_t, prelink_tmp_t, prelude_correlator_config_t, prelude_lml_tmp_t, printconf_t, proc_t, procmail_home_t, procmail_tmp_t, psad_etc_t, psad_tmp_t, ptal_etc_t, pulseaudio_exec_t, pulseaudio_home_t, puppet_etc_t, puppet_tmp_t, puppetmaster_tmp_t, qmail_etc_t, qpidd_tmp_t, quantum_tmp_t, racoon_tmp_t, radiusd_etc_t, radvd_etc_t, realmd_tmp_t, rgmanager_tmp_t, rhev_agentd_tmp_t, rhev_agentd_var_run_t, ricci_tmp_t, rlogind_home_t, rlogind_tmp_t, rpm_exec_t, rpm_script_tmp_t, rpm_tmp_t, rpm_var_cache_t, rpm_var_lib_t, rssh_ro_t, rssh_rw_t, rsync_etc_t, rsync_tmp_t, samba_etc_t, samba_net_tmp_t, samba_var_t, screen_exec_t, screen_home_t, secadm_sudo_tmp_t, sectool_tmp_t, security_t, selinux_config_t, selinux_login_config_t, selinux_munin_plugin_tmp_t, semanage_tmp_t, sendmail_tmp_t, services_munin_plugin_tmp_t, session_dbusd_tmp_t, sge_tmp_t, shell_exec_t, shorewall_etc_t, shorewall_tmp_t, shutdown_etc_t, shutdown_exec_t, slapd_etc_t, slapd_tmp_t, smbd_tmp_t, smoltclient_tmp_t, smsd_tmp_t, snort_etc_t, snort_tmp_t, sosreport_tmp_t, soundd_etc_t, soundd_tmp_t, spamc_home_t, spamc_tmp_t, spamd_etc_t, spamd_tmp_t, squid_conf_t, squid_tmp_t, squirrelmail_spool_t, src_t, ssh_agent_exec_t, ssh_agent_tmp_t, ssh_home_t, sssd_conf_t, sssd_public_t, sssd_var_lib_t, staff_sudo_tmp_t, stapserver_tmp_t, stunnel_etc_t, stunnel_tmp_t, svc_conf_t, svirt_home_t, svirt_tmp_t, swat_tmp_t, sysadm_passwd_tmp_t, sysadm_sudo_tmp_t, sysfs_t, syslog_conf_t, syslogd_tmp_t, system_conf_t, system_cronjob_tmp_t, system_cronjob_var_lib_t, system_dbusd_tmp_t, system_dbusd_var_lib_t, system_mail_tmp_t, system_munin_plugin_tmp_t, systemd_logind_sessions_t, systemd_logind_var_run_t, systemd_passwd_agent_exec_t, systemd_passwd_var_run_t, systemd_systemctl_exec_t, tcpd_tmp_t, telepathy_cache_home_t, telepathy_data_home_t, telepathy_gabble_cache_home_t, telepathy_gabble_exec_t, telepathy_gabble_tmp_t, telepathy_idle_exec_t, telepathy_idle_tmp_t, telepathy_logger_cache_home_t, telepathy_logger_data_home_t, telepathy_logger_exec_t, telepathy_logger_tmp_t, telepathy_mission_control_cache_home_t, telepathy_mission_control_data_home_t, telepathy_mission_control_exec_t, telepathy_mission_control_home_t, telepathy_mission_control_tmp_t, telepathy_msn_exec_t, telepathy_msn_tmp_t, telepathy_salut_exec_t, telepathy_salut_tmp_t, telepathy_sofiasip_exec_t, telepathy_sofiasip_tmp_t, telepathy_stream_engine_exec_t, telepathy_stream_engine_tmp_t, telepathy_sunshine_exec_t, telepathy_sunshine_home_t, telepathy_sunshine_tmp_t, telnetd_tmp_t, tetex_data_t, textrel_shlib_t, tftpd_etc_t, tgtd_tmp_t, thumb_home_t, thumb_tmp_t, tmp_t, tomcat_tmp_t, tor_etc_t, tuned_etc_t, tuned_rw_etc_t, tuned_tmp_t, tvtime_home_t, tvtime_tmp_t, udev_etc_t, udev_var_run_t, ulogd_etc_t, uml_ro_t, uml_rw_t, uml_tmp_t, unconfined_munin_plugin_tmp_t, update_modules_tmp_t, updpwd_exec_t, user_cron_spool_t, user_fonts_cache_t, user_fonts_config_t, user_fonts_t, user_home_t, user_mail_tmp_t, user_tmp_t, user_tmpfs_t, userhelper_conf_t, usr_t, uucpd_tmp_t, var_auth_t, var_lib_t, var_log_t, var_spool_t, var_t, varnishd_etc_t, varnishd_tmp_t, virt_content_t, virt_etc_t, virt_home_t, virt_tmp_t, vmware_conf_t, vmware_file_t, vmware_host_tmp_t, vmware_tmp_t, vpnc_tmp_t, webadm_tmp_t, webalizer_etc_t, webalizer_tmp_t, wine_home_t, wine_tmp_t, wireshark_home_t, wireshark_tmp_t, wtmp_t, xauth_exec_t, xauth_home_t, xauth_tmp_t, xdm_etc_t, xdm_exec_t, xdm_home_t, xdm_lock_t, xdm_log_t, xdm_rw_etc_t, xdm_spool_t, xdm_tmp_t, xdm_tmpfs_t, xdm_unconfined_exec_t, xdm_var_lib_t, xdm_var_run_t, xend_tmp_t, xenstored_tmp_t, xkb_var_lib_t, xserver_etc_t, xserver_exec_t, xserver_log_t, xserver_tmpfs_t, xsession_exec_t, ypbind_tmp_t, ypserv_conf_t, ypserv_tmp_t, zabbix_tmp_t, zarafa_deliver_tmp_t, zarafa_etc_t, zarafa_indexer_tmp_t, zarafa_server_tmp_t, zarafa_var_lib_t, zebra_conf_t, zebra_tmp_t. 
Then execute: 
restorecon -v '/opt/VirtualBox/virtualbox.desktop'


*****  Plugin catchall (1.44 confidence) suggests  ***************************

If you believe that gnome-shell should be allowed read access on the virtualbox.desktop 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 gnome-shell /var/log/audit/audit.log | audit2allow -M mypol
# semodule -i mypol.pp

Additional Information:
Source Context                system_u:system_r:xdm_t:s0-s0:c0.c1023
Target Context                unconfined_u:object_r:default_t:s0
Target Objects                /opt/VirtualBox/virtualbox.desktop [ file ]
Source                        gnome-shell
Source Path                   /usr/bin/gnome-shell
Port                          <Unknown>
Host                          (removed)
Source RPM Packages           gnome-shell-3.6.3.1-1.fc18.x86_64
Target RPM Packages           
Policy RPM                    selinux-policy-3.11.1-94.fc18.noarch
Selinux Enabled               True
Policy Type                   targeted
Enforcing Mode                Enforcing
Host Name                     (removed)
Platform                      Linux (removed) 3.9.2-200.fc18.x86_64 #1 SMP Mon
                              May 13 13:59:47 UTC 2013 x86_64 x86_64
Alert Count                   1
First Seen                    2013-05-15 21:38:39 PDT
Last Seen                     2013-05-15 21:38:39 PDT
Local ID                      676a2382-a4a9-4abf-993f-7ecbc07a08a1

Raw Audit Messages
type=AVC msg=audit(1368679119.214:262): avc:  denied  { read } for  pid=1416 comm="gnome-shell" name="virtualbox.desktop" dev="dm-0" ino=2752592 scontext=system_u:system_r:xdm_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:default_t:s0 tclass=file


type=SYSCALL msg=audit(1368679119.214:262): arch=x86_64 syscall=open success=no exit=EACCES a0=36c24b0 a1=0 a2=0 a3=2 items=0 ppid=1184 pid=1416 auid=42 uid=42 gid=42 euid=42 suid=42 fsuid=42 egid=42 sgid=42 fsgid=42 ses=1 tty=(none) comm=gnome-shell exe=/usr/bin/gnome-shell subj=system_u:system_r:xdm_t:s0-s0:c0.c1023 key=(null)

Hash: gnome-shell,xdm_t,default_t,file,read

audit2allow

#============= xdm_t ==============
allow xdm_t default_t:file read;

audit2allow -R
require {
	type xdm_t;
}

#============= xdm_t ==============
files_read_default_files(xdm_t)


Additional info:
reporter:       libreport-2.1.4
hashmarkername: setroubleshoot
kernel:         3.9.2-200.fc18.x86_64
type:           libreport