When cron_userdomain_transition boolean is set to on, the user cronjobs
are supposed to run in their domains. Without this patch the default
context is not properly computed:
$ /usr/sbin/getdefaultcon user_u system_u:system_r:crond_t:s0
/usr/sbin/getdefaultcon: Invalid argument
$ /usr/sbin/getdefaultcon staff_u system_u:system_r:crond_t:s0
staff_u:sysadm_r:sysadm_t:s0
With this patch applied:
$ /usr/sbin/getdefaultcon user_u system_u:system_r:crond_t:s0
user_u:user_r:user_t:s0
$ /usr/sbin/getdefaultcon staff_ system_u:system_r:crond_t:s0
staff_u:staff_r:staff_t:s0
When SELinux user system_u starts crond during system booting up, its
cron job process should be in the system_cronjob_t domain, which has
the required entrypoint permission on system crontab files labeled as
system_cron_spool_t. Otherwise we can run into below error messages:
Jan 31 08:40:53 QtCao crond[535]: (system_u) Unauthorized SELinux context (/etc/crontab)
Jan 31 08:40:53 QtCao crond[535]: (system_u) Unauthorized SELinux context (/etc/cron.d/sysstat)
The weird thing is that the getdefaultcon command even can not fetch
"system_r:cronjob_t:s0" but "system_r:logrotate_t:s0" ! After fixing
default_contexts files the getdefaultcon command could properly fetch
"system_r:system_cronjob_t:s0" :
root@QtCao:/root> getdefaultcon system_u system_u:system_r:crond_t:s0
system_u:system_r:logrotate_t:s0
root@QtCao:/root>
root@QtCao:/root> grep crond_t /etc/selinux/refpolicy-mls/contexts/default_contexts
system_r:crond_t:s0 user_r:cronjob_t:s0 staff_r:cronjob_t:s0 sysadm_r:cronjob_t:s0 system_r:system_cronjob_t:s0 unconfined_r:unconfined_cronjob_t:s0
root@QtCao:/root>
root@QtCao:/root> getdefaultcon system_u system_u:system_r:crond_t:s0
system_u:system_r:system_cronjob_t:s0
root@QtCao:/root>
Signed-off-by: Harry Ciao <qingtao.cao@windriver.com>
Laurent Bigonville
Harry Ciao
Chris PeBenito