public/shell.te

# Domain for shell processes spawned by ADB or console service.
type shell, domain, mlstrustedsubject;
type shell_exec, system_file_type, exec_type, file_type;

# Create and use network sockets.
net_domain(shell)

# logcat
read_logd(shell)
control_logd(shell)
get_prop(shell, logd_prop)
# logcat -L (directly, or via dumpstate)
allow shell pstorefs:dir search;
allow shell pstorefs:file r_file_perms;

# Root fs.
allow shell rootfs:dir r_dir_perms;

# read files in /data/anr
allow shell anr_data_file:dir r_dir_perms;
allow shell anr_data_file:file r_file_perms;

# Access /data/local/tmp.
allow shell shell_data_file:dir create_dir_perms;
allow shell shell_data_file:file create_file_perms;
allow shell shell_data_file:file rx_file_perms;
allow shell shell_data_file:lnk_file create_file_perms;

# Access /data/local/tests.
allow shell shell_test_data_file:dir create_dir_perms;
allow shell shell_test_data_file:file create_file_perms;
allow shell shell_test_data_file:file rx_file_perms;
allow shell shell_test_data_file:lnk_file create_file_perms;
allow shell shell_test_data_file:sock_file create_file_perms;

# Read and delete from /data/local/traces.
allow shell trace_data_file:file { r_file_perms unlink };
allow shell trace_data_file:dir { r_dir_perms remove_name write };

# Access /data/misc/profman.
allow shell profman_dump_data_file:dir { write remove_name r_dir_perms };
allow shell profman_dump_data_file:file { unlink r_file_perms };

# Read/execute files in /data/nativetest
userdebug_or_eng(`
  allow shell nativetest_data_file:dir r_dir_perms;
  allow shell nativetest_data_file:file rx_file_perms;
')

# adb bugreport
unix_socket_connect(shell, dumpstate, dumpstate)

allow shell devpts:chr_file rw_file_perms;
allow shell tty_device:chr_file rw_file_perms;
allow shell console_device:chr_file rw_file_perms;

allow shell input_device:dir r_dir_perms;
allow shell input_device:chr_file r_file_perms;

r_dir_file(shell, system_file)
allow shell system_file:file x_file_perms;
allow shell toolbox_exec:file rx_file_perms;
allow shell shell_exec:file rx_file_perms;
allow shell zygote_exec:file rx_file_perms;

userdebug_or_eng(`
  # "systrace --boot" support - allow boottrace service to run
  allow shell boottrace_data_file:dir rw_dir_perms;
  allow shell boottrace_data_file:file create_file_perms;
')

# allow shell access to services
allow shell servicemanager:service_manager list;
# don't allow shell to access GateKeeper service
# TODO: why is this so broad? Tightening candidate? It needs at list:
# - dumpstate_service (so it can receive dumpstate progress updates)
allow shell {
  service_manager_type
  -apex_service
  -dnsresolver_service
  -gatekeeper_service
  -hal_keymint_service
  -hal_secureclock_service
  -hal_sharedsecret_service
  -incident_service
  -installd_service
  -mdns_service
  -netd_service
  -system_suspend_control_internal_service
  -system_suspend_control_service
  -virtual_touchpad_service
  -vold_service
  -default_android_service
}:service_manager find;
allow shell dumpstate:binder call;

# allow shell to get information from hwservicemanager
# for instance, listing hardware services with lshal
hwbinder_use(shell)
allow shell hwservicemanager:hwservice_manager list;

# allow shell to look through /proc/ for lsmod, ps, top, netstat, vmstat.
r_dir_file(shell, proc_net_type)

allow shell {
  proc_asound
  proc_filesystems
  proc_interrupts
  proc_loadavg # b/124024827
  proc_meminfo
  proc_modules
  proc_pid_max
  proc_slabinfo
  proc_stat
  proc_timer
  proc_uptime
  proc_version
  proc_vmstat
  proc_zoneinfo
}:file r_file_perms;

# allow listing network interfaces under /sys/class/net.
allow shell sysfs_net:dir r_dir_perms;

r_dir_file(shell, cgroup)
allow shell cgroup_desc_file:file r_file_perms;
allow shell cgroup_desc_api_file:file r_file_perms;
allow shell vendor_cgroup_desc_file:file r_file_perms;
r_dir_file(shell, cgroup_v2)
allow shell domain:dir { search open read getattr };
allow shell domain:{ file lnk_file } { open read getattr };

# statvfs() of /proc and other labeled filesystems
# (yaffs2, jffs2, ext2, ext3, ext4, xfs, btrfs, f2fs, squashfs, overlay)
allow shell { proc labeledfs }:filesystem getattr;

# stat() of /dev
allow shell device:dir getattr;

# allow shell to read /proc/pid/attr/current for ps -Z
allow shell domain:process getattr;

# Allow pulling the SELinux policy for CTS purposes
allow shell selinuxfs:dir r_dir_perms;
allow shell selinuxfs:file r_file_perms;

# enable shell domain to read/write files/dirs for bootchart data
# User will creates the start and stop file via adb shell
# and read other files created by init process under /data/bootchart
allow shell bootchart_data_file:dir rw_dir_perms;
allow shell bootchart_data_file:file create_file_perms;

# Make sure strace works for the non-privileged shell user
allow shell self:process ptrace;

# allow shell to get battery info
allow shell sysfs:dir r_dir_perms;
allow shell sysfs_batteryinfo:dir r_dir_perms;
allow shell sysfs_batteryinfo:file r_file_perms;

# Allow access to ion memory allocation device.
allow shell ion_device:chr_file rw_file_perms;

#
# filesystem test for insecure chr_file's is done
# via a host side test
#
allow shell dev_type:dir r_dir_perms;
allow shell dev_type:chr_file getattr;

# /dev/fd is a symlink
allow shell proc:lnk_file getattr;

#
# filesystem test for insucre blk_file's is done
# via hostside test
#
allow shell dev_type:blk_file getattr;

# read selinux policy files
allow shell file_contexts_file:file r_file_perms;
allow shell property_contexts_file:file r_file_perms;
allow shell seapp_contexts_file:file r_file_perms;
allow shell service_contexts_file:file r_file_perms;
allow shell sepolicy_file:file r_file_perms;

# Allow shell to start up vendor shell
allow shell vendor_shell_exec:file rx_file_perms;

# Everything is labeled as rootfs in recovery mode. Allow shell to
# execute them.
recovery_only(`
  allow shell rootfs:file rx_file_perms;
')

###
### Neverallow rules
###

# Do not allow shell to talk directly to security HAL services other than
# hal_remotelyprovisionedcomponent_service
neverallow shell {
  hal_keymint_service
  hal_secureclock_service
  hal_sharedsecret_service
}:service_manager find;

# Do not allow shell to hard link to any files.
# In particular, if shell hard links to app data
# files, installd will not be able to guarantee the deletion
# of the linked to file. Hard links also contribute to security
# bugs, so we want to ensure the shell user never has this
# capability.
neverallow shell file_type:file link;

# Do not allow privileged socket ioctl commands
neverallowxperm shell domain:{ rawip_socket tcp_socket udp_socket } ioctl priv_sock_ioctls;

# limit shell access to sensitive char drivers to
# only getattr required for host side test.
neverallow shell {
  fuse_device
  hw_random_device
  port_device
}:chr_file ~getattr;

# Limit shell to only getattr on blk devices for host side tests.
neverallow shell dev_type:blk_file ~getattr;

# b/30861057: Shell access to existing input devices is an abuse
# vector. The shell user can inject events that look like they
# originate from the touchscreen etc.
# Everyone should have already moved to UiAutomation#injectInputEvent
# if they are running instrumentation tests (i.e. CTS), Monkey for
# their stress tests, and the input command (adb shell input ...) for
# injecting swipes and things.
neverallow shell input_device:chr_file no_w_file_perms;