svirt_tcg_selinux (8) - Linux Manuals
svirt_tcg_selinux: Security Enhanced Linux Policy for the svirt_tcg processes
NAME
svirt_tcg_selinux - Security Enhanced Linux Policy for the svirt_tcg processesDESCRIPTION
Security-Enhanced Linux secures the svirt_tcg processes via flexible mandatory access control.
The svirt_tcg processes execute with the svirt_tcg_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 svirt_tcg_t
ENTRYPOINTS
The svirt_tcg_t SELinux type can be entered via the qemu_exec_t file type.
The default entrypoint paths for the svirt_tcg_t domain are the following:
/usr/libexec/qemu.*, /usr/bin/qemu-system-.*, /usr/bin/qemu, /usr/bin/qemu-kvm
PROCESS TYPES
SELinux defines process types (domains) for each process running on the systemYou can see the context of a process using the -Z option to psP Policy governs the access confined processes have to files. SELinux svirt_tcg policy is very flexible allowing users to setup their svirt_tcg processes in as secure a method as possible.
The following process types are defined for svirt_tcg:
svirt_tcg_t
Note: semanage permissive -a svirt_tcg_t can be used to make the process type svirt_tcg_t permissive. SELinux does not deny access to permissive process types, but the AVC (SELinux denials) messages are still generated.
MCS Constrained
The SELinux process type svirt_tcg_t is an MCS (Multi Category Security) constrained type. Sometimes this separation is referred to as sVirt. These types are usually used for securing multi-tenant environments, such as virtualization, containers or separation of users. The tools used to launch MCS types, pick out a different MCS label for each process group.For example one process might be launched with svirt_tcg_t:s0:c1,c2, and another process launched with svirt_tcg_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
BOOLEANS
SELinux policy is customizable based on least access required. svirt_tcg policy is extremely flexible and has several booleans that allow you to manipulate the policy and run svirt_tcg with the tightest access possible.
If you want to deny any process from ptracing or debugging any other processes, you must turn on the deny_ptrace boolean. Enabled by default.
setsebool -P deny_ptrace 1
If you want to allow all domains to use other domains file descriptors, you must turn on the domain_fd_use boolean. Enabled by default.
setsebool -P domain_fd_use 1
If you want to allow all domains to have the kernel load modules, you must turn on the domain_kernel_load_modules boolean. Disabled by default.
setsebool -P domain_kernel_load_modules 1
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 enable reading of urandom for all domains, you must turn on the global_ssp boolean. Disabled by default.
setsebool -P global_ssp 1
If you want to allow confined virtual guests to use serial/parallel communication ports, you must turn on the virt_use_comm boolean. Disabled by default.
setsebool -P virt_use_comm 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 read fuse files, you must turn on the virt_use_fusefs boolean. Disabled by default.
setsebool -P virt_use_fusefs 1
If you want to allow confined virtual guests to manage nfs files, you must turn on the virt_use_nfs boolean. Disabled by default.
setsebool -P virt_use_nfs 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
If you want to allow confined virtual guests to manage cifs files, you must turn on the virt_use_samba boolean. Disabled by default.
setsebool -P virt_use_samba 1
If you want to allow confined virtual guests to interact with the sanlock, you must turn on the virt_use_sanlock boolean. Disabled by default.
setsebool -P virt_use_sanlock 1
If you want to allow confined virtual guests to use usb devices, you must turn on the virt_use_usb boolean. Enabled by default.
setsebool -P virt_use_usb 1
If you want to allow confined virtual guests to interact with the xserver, you must turn on the virt_use_xserver boolean. Disabled by default.
setsebool -P virt_use_xserver 1
MANAGED FILES
The SELinux process type svirt_tcg_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.
anon_inodefs_t
cifs_t
dosfs_t
fusefs_t
nfs_t
qemu_var_run_t
svirt_home_t
svirt_image_t
svirt_tmp_t
svirt_tmpfs_t
usbfs_t
virt_cache_t
COMMANDS
semanage fcontext can also be used to manipulate default file context mappings.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.