Security-Enhanced Linux secures the svirt processes via flexible mandatory access control.
The svirt processes execute with the svirt_t SELinux type. You can check if you have these processes running by executing the ps command with the -Z qualifier.
ps -eZ | grep svirt_t
The svirt_t SELinux type can be entered via the qemu_exec_t file type.
The default entrypoint paths for the svirt_t domain are the following:
You can see the context of a process using the -Z option to psP Policy governs the access confined processes have to files. SELinux svirt policy is very flexible allowing users to setup their svirt processes in as secure a method as possible.
The following process types are defined for svirt:
svirt_t, svirt_tcg_t, svirt_qemu_net_t, svirt_socket_t, svirt_kvm_net_t
Note: semanage permissive -a svirt_t can be used to make the process type svirt_t permissive. SELinux does not deny access to permissive process types, but the AVC (SELinux denials) messages are still generated.
For example one process might be launched with svirt_t:s0:c1,c2, and another process launched with svirt_t:s0:c3,c4. The SELinux kernel only allows these processes can only write to content with a matching MCS label, or a MCS Label of s0. A process running with the MCS level of s0:c1,c2 is not allowed to write to content with the MCS label of s0:c3,c4
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 confined virtual guests to use executable memory and executable stack, you must turn on the virt_use_execmem boolean. Disabled by default.
setsebool -P virt_use_execmem 1
If you want to allow confined virtual guests to interact with rawip sockets, you must turn on the virt_use_rawip boolean. Disabled by default.
setsebool -P virt_use_rawip 1
The SELinux process type svirt_t can manage files labeled with the following file types. The paths listed are the default paths for these file types. Note the processes UID still need to have DAC permissions.
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 svirt policy is very flexible allowing users to setup their svirt processes in as secure a method as possible.
STANDARD FILE CONTEXT
SELinux defines the file context types for the svirt, 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 svirt_home_t '/srv/mysvirt_content(/.*)?'
restorecon -R -v /srv/mysvirt_content
Note: SELinux often uses regular expressions to specify labels that match multiple files.
The following file types are defined for svirt:
- Set files with the svirt_home_t type, if you want to store svirt files in the users home directory.
- Set files with the svirt_image_t type, if you want to treat the files as svirt image data.
- Set files with the svirt_tmp_t type, if you want to store svirt temporary files in the /tmp directories.
- Set files with the svirt_tmpfs_t type, if you want to store svirt files on a tmpfs file system.
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.