c9630dc6a1
external/toybox commit a583afc812cf7be74ebab72294c8df485908ff04 started having dmesg use /dev/kmsg, which is unreadable to the unprivileged shell user. Revoke syslog(2) to the shell user for consistency. The kernel dmesg log is a source of kernel pointers, which can leak kASLR information from the kernel. Restricting access to kernel information will make attacks against Android more difficult. Having said that, dmesg information is still available from "adb bugreport", so this change doesn't completely shutdown kernel info leaks. This change essentially reverts us to the state we were in between Nov 8 2011 and May 27 2014. During that almost 3 year period, the unprivileged shell user was unable to access dmesg, and there was only one complaint during that time. References: * https://android.googlesource.com/platform/system/core/+/f9557fb * https://android.googlesource.com/platform/system/sepolicy/+/f821b5a TODO: Further unify /dev/kmsg permissions with syslog_read permissions. Test: policy compiles, no dmesg output Change-Id: Icfff6f765055bdbbe85f302b781aed2568ef532f
184 lines
5.8 KiB
Text
184 lines
5.8 KiB
Text
# Domain for shell processes spawned by ADB or console service.
|
|
type shell, domain, mlstrustedsubject;
|
|
type shell_exec, exec_type, file_type;
|
|
|
|
# Create and use network sockets.
|
|
net_domain(shell)
|
|
|
|
# Run app_process.
|
|
# XXX Transition into its own domain?
|
|
app_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;
|
|
# logpersistd (nee logcatd) files
|
|
userdebug_or_eng(`
|
|
allow shell misc_logd_file:dir r_dir_perms;
|
|
allow shell misc_logd_file: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/misc/profman.
|
|
allow shell profman_dump_data_file:dir { search getattr write remove_name };
|
|
allow shell profman_dump_data_file:file { getattr unlink };
|
|
|
|
# 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 rw_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;
|
|
|
|
r_dir_file(shell, apk_data_file)
|
|
|
|
# Set properties.
|
|
set_prop(shell, shell_prop)
|
|
set_prop(shell, ctl_bugreport_prop)
|
|
set_prop(shell, ctl_dumpstate_prop)
|
|
set_prop(shell, dumpstate_prop)
|
|
set_prop(shell, debug_prop)
|
|
set_prop(shell, powerctl_prop)
|
|
set_prop(shell, log_tag_prop)
|
|
set_prop(shell, wifi_log_prop)
|
|
userdebug_or_eng(`set_prop(shell, log_prop)')
|
|
userdebug_or_eng(`set_prop(shell, logpersistd_logging_prop)')
|
|
|
|
# systrace support - allow atrace to run
|
|
allow shell debugfs_tracing:dir r_dir_perms;
|
|
allow shell debugfs_tracing:file rw_file_perms;
|
|
allow shell debugfs_trace_marker:file getattr;
|
|
allow shell atrace_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;
|
|
set_prop(shell, persist_debug_prop)
|
|
')
|
|
|
|
# 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 -gatekeeper_service -netd_service}:service_manager find;
|
|
allow shell dumpstate:binder call;
|
|
|
|
# allow shell to look through /proc/ for ps, top, netstat
|
|
r_dir_file(shell, proc)
|
|
r_dir_file(shell, proc_net)
|
|
allow shell proc_interrupts:file r_file_perms;
|
|
allow shell proc_meminfo:file r_file_perms;
|
|
allow shell proc_stat:file r_file_perms;
|
|
allow shell proc_timer:file r_file_perms;
|
|
allow shell proc_zoneinfo:file r_file_perms;
|
|
r_dir_file(shell, cgroup)
|
|
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)
|
|
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_batteryinfo:file r_file_perms;
|
|
allow shell sysfs:dir r_dir_perms;
|
|
|
|
# Allow access to ion memory allocation device.
|
|
allow shell ion_device:chr_file rw_file_perms;
|
|
|
|
# Access to /data/media.
|
|
# This should be removed if sdcardfs is modified to alter the secontext for its
|
|
# accesses to the underlying FS.
|
|
allow shell media_rw_data_file:dir create_dir_perms;
|
|
allow shell media_rw_data_file:file create_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;
|
|
|
|
###
|
|
### 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
|
|
kmem_device
|
|
}:chr_file ~getattr;
|
|
|
|
# Limit shell to only getattr on blk devices for host side tests.
|
|
neverallow shell dev_type:blk_file ~getattr;
|