Security-Enhanced Linux secures the blktap processes via flexible mandatory access control.
The blktap processes execute with the blktap_t SELinux type. You can check if you have these processes running by executing the ps command with the -Z qualifier.
For example:
ps -eZ | grep blktap_t
The blktap_t SELinux type can be entered via the blktap_exec_t file type.
The default entrypoint paths for the blktap_t domain are the following:
/usr/sbin/tapdisk, /usr/sbin/blktapctrl
You can see the context of a process using the -Z option to psP Policy governs the access confined processes have to files. SELinux blktap policy is very flexible allowing users to setup their blktap processes in as secure a method as possible.
The following process types are defined for blktap:
blktap_t
Note: semanage permissive -a blktap_t can be used to make the process type blktap_t permissive. SELinux does not deny access to permissive process types, but the AVC (SELinux denials) messages are still generated.
If you want to allow all domains to execute in fips_mode, you must turn on the fips_mode boolean. Enabled by default.
setsebool -P fips_mode 1
If you want to allow xend to run blktapctrl/tapdisk. Not required if using dedicated logical volumes for disk images, you must turn on the xend_run_blktap boolean. Enabled by default.
setsebool -P xend_run_blktap 1
You can see the context of a file using the -Z option to lsP Policy governs the access confined processes have to these files. SELinux blktap policy is very flexible allowing users to setup their blktap processes in as secure a method as possible.
STANDARD FILE CONTEXT
SELinux defines the file context types for the blktap, if you wanted to store files with these types in a diffent paths, you need to execute the semanage command to sepecify alternate labeling and then use restorecon to put the labels on disk.
semanage fcontext -a -t blktap_var_run_t '/srv/myblktap_content(/.*)?'
restorecon -R -v /srv/myblktap_content
Note: SELinux often uses regular expressions to specify labels that match multiple files.
The following file types are defined for blktap:
blktap_exec_t
- Set files with the blktap_exec_t type, if you want to transition an executable to the blktap_t domain.
blktap_var_run_t
- Set files with the blktap_var_run_t type, if you want to store the blktap files under the /run or /var/run directory.
Note: File context can be temporarily modified with the chcon command. If you want to permanently change the file context you need to use the semanage fcontext command. This will modify the SELinux labeling database. You will need to use restorecon to apply the labels.
semanage permissive can also be used to manipulate whether or not a process type is permissive.
semanage module can also be used to enable/disable/install/remove policy modules.
semanage boolean can also be used to manipulate the booleans
system-config-selinux is a GUI tool available to customize SELinux policy settings.