platform_system_sepolicy/public/shell.te
Bart Van Assche 4374a1fd83 Stop using the bdev_type and sysfs_block_type SELinux attributes
Stop using these SELinux attributes since the apexd and init SELinux
policies no longer rely on these attributes.

The difference between the previous versions of this patch and the
current patch is that the current patch does not remove any SELinux
attributes. See also
https://android-review.googlesource.com/c/platform/system/sepolicy/+/1850656.
See also
https://android-review.googlesource.com/c/platform/system/sepolicy/+/1862919.

This patch includes a revert of commit 8b2b951349 ("Restore permission
for shell to list /sys/class/block").  That commit is no longer necessary
since it was a bug fix for the introduction of the sysfs_block type.

Bug: 202520796
Test: source build/envsetup.sh && lunch aosp_x86_64 && m && launch_cvd
Change-Id: I73e1133af8146c154af95d4b96132e49dbec730c
Signed-off-by: Bart Van Assche <bvanassche@google.com>
2021-10-29 15:22:09 -07:00

228 lines
7 KiB
Text

# 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)
# 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 tzdatacheck_exec:file rx_file_perms;
allow shell shell_exec:file rx_file_perms;
allow shell zygote_exec:file rx_file_perms;
r_dir_file(shell, apk_data_file)
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
-incident_service
-installd_service
-iorapd_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 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;