1type crosvm, domain, coredomain; 2type crosvm_exec, system_file_type, exec_type, file_type; 3type crosvm_tmpfs, file_type; 4 5# Let crosvm open VM manager devices such as /dev/kvm. 6allow crosvm vm_manager_device_type:chr_file rw_file_perms; 7 8# Most other domains shouldn't access /dev/kvm. 9neverallow { domain -crosvm -ueventd -shell } kvm_device:chr_file getattr; 10neverallow { domain -crosvm -ueventd } kvm_device:chr_file ~getattr; 11neverallowxperm { domain -crosvm } kvm_device:chr_file ioctl ~{ KVM_CHECK_EXTENSION }; 12 13# Most other domains shouldn't access other vm managers either. 14# These restrictions need to be slightly looser than for kvm_device to allow 15# for different implementations. 16neverallow { coredomain appdomain -crosvm -ueventd -shell } vm_manager_device_type:chr_file getattr; 17neverallow { coredomain appdomain -crosvm -ueventd } vm_manager_device_type:chr_file ~getattr; 18 19# Let crosvm create temporary files. 20tmpfs_domain(crosvm) 21 22# Let crosvm receive file descriptors from VirtualizationService. 23allow crosvm virtualizationmanager:fd use; 24 25# Allow sending VirtualizationService the failure reason and console/log from the VM via pipe. 26allow crosvm virtualizationmanager:fifo_file write; 27 28# Let crosvm read the composite disk images (virtualizationservice_data_file), APEXes 29# (staging_data_file), APKs (apk_data_file and shell_data_file where the latter is for test apks in 30# /data/local/tmp), and instance.img (app_data_file). Note that the open permission is not given as 31# the files are passed as file descriptors. 32allow crosvm { 33 virtualizationservice_data_file 34 staging_data_file 35 apk_data_file 36 app_data_file 37 privapp_data_file 38 apex_compos_data_file 39 shell_data_file 40}:file { getattr read ioctl lock }; 41 42# Allow searching the directory where the composite disk images are. 43allow crosvm virtualizationservice_data_file:dir search; 44 45# Allow crosvm to mlock guest memory. 46allow crosvm self:capability ipc_lock; 47 48# Let crosvm access its control socket as created by VS. 49# read, write, getattr: listener socket polling 50# accept: listener socket accepting new connection 51# Note that the open permission is not given as the socket is passed by FD. 52allow crosvm virtualizationmanager:unix_stream_socket { accept read write getattr getopt }; 53 54# Let crosvm open test artifacts under /data/local/tmp with file path. (e.g. custom pvmfw.img) 55userdebug_or_eng(` 56 allow crosvm shell_data_file:dir search; 57 allow crosvm shell_data_file:file open; 58') 59 60# The instance image and the composite image should be writable as well because they could represent 61# mutable disks. 62allow crosvm { 63 virtualizationservice_data_file 64 app_data_file 65 privapp_data_file 66 apex_compos_data_file 67}:file write; 68 69# Allow crosvm to pipe console log to shell or app which could be the owner of a VM. 70allow crosvm adbd:fd use; 71allow crosvm adbd:unix_stream_socket { read write }; 72 73# crosvm tries to use netlink sockets as part its APCI implementation, but we don't need it for AVF (b/228077254) 74dontaudit crosvm self:netlink_generic_socket create_socket_perms_no_ioctl; 75 76# crosvm can write files in /data/local/tmp which are usually used for instance.img and logging by 77# compliance tests and demo apps. Write access to instance.img is particularily important because 78# the VM has to initialize the disk image on its first boot. Note that open access is still not 79# granted because the files are expected to be opened by the owner of the VM (apps or shell in case 80# when the vm is created by the `vm` tool) and handed over to crosvm as FD. 81allow crosvm shell_data_file:file write; 82 83# crosvm tries to read serial device, including the write-only pipe from virtualizationmanager (to 84# forward console/log to the host logcat). 85# crosvm only needs write permission, so dontaudit read 86dontaudit crosvm virtualizationmanager:fifo_file read; 87 88# Required for crosvm to start gdb-server to enable debugging of guest kernel. 89allow crosvm self:tcp_socket { bind create read setopt write accept listen }; 90allow crosvm port:tcp_socket name_bind; 91allow crosvm adbd:unix_stream_socket ioctl; 92allow crosvm node:tcp_socket node_bind; 93 94# Don't allow crosvm to open files that it doesn't own. 95# This is important because a malicious application could try to start a VM with a composite disk 96# image referring by name to files which it doesn't have permission to open, trying to get crosvm to 97# open them on its behalf. By preventing crosvm from opening any other files we prevent this 98# potential privilege escalation. See http://b/192453819 for more discussion. 99neverallow crosvm { 100 virtualizationservice_data_file 101 staging_data_file 102 apk_data_file 103 app_data_file 104 privapp_data_file 105 userdebug_or_eng(`-shell_data_file') 106}:file open; 107 108# Don't allow crosvm to have access to ordinary vendor files that are not for VMs. 109full_treble_only(` 110 neverallow crosvm { 111 vendor_file_type 112 -vendor_vm_file 113 -vendor_vm_data_file 114 # These types are not required for crosvm, but the access is granted to globally in domain.te 115 # thus should be exempted here. 116 -vendor_configs_file 117 -vndk_sp_file 118 -vendor_task_profiles_file 119 }:file *; 120') 121 122# Only allow crosvm to read app data files for clients that can start 123# VMs. Note that the use of app data files is further restricted 124# inside the virtualizationservice by checking the label of all disk 125# image files. 126neverallow crosvm { 127 app_data_file_type 128 -app_data_file 129 -privapp_data_file 130 -shell_data_file 131}:file read; 132 133# Only virtualizationmanager can run crosvm 134neverallow { 135 domain 136 -crosvm 137 -virtualizationmanager 138} crosvm_exec:file no_x_file_perms; 139