platform_system_sepolicy/recovery.te
Stephen Smalley f3c3a1aa33 Remove execute_no_trans from unconfineddomain.
execute_no_trans controls whether a domain can execve a program
without switching to another domain.  Exclude this permission from
unconfineddomain, add it back to init, init_shell, and recovery for
files in / and /system, and to kernel for files in / (to permit
execution of init prior to setcon).  Prohibit it otherwise for the
kernel domain via neverallow.  This ensures that if a kernel task
attempts to execute a kernel usermodehelper for which no domain transition
is defined, the exec will fail.

Change-Id: Ie7b2349923672dd4f5faf7c068a6e5994fd0e4e3
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
2014-06-19 22:38:28 +00:00

88 lines
3.4 KiB
Text

# recovery console (used in recovery init.rc for /sbin/recovery)
# Declare the domain unconditionally so we can always reference it
# in neverallow rules.
type recovery, domain;
# But the allow rules are only included in the recovery policy.
# Otherwise recovery is only allowed the domain rules.
recovery_only(`
allow recovery rootfs:file { entrypoint execute };
permissive_or_unconfined(recovery)
allow recovery self:capability { chown dac_override fowner fsetid setfcap setuid setgid sys_admin sys_tty_config };
# Set security contexts on files that are not known to the loaded policy.
allow recovery self:capability2 mac_admin;
# Run helpers from / or /system without changing domain.
allow recovery rootfs:file execute_no_trans;
allow recovery system_file:file execute_no_trans;
# Mount filesystems.
allow recovery rootfs:dir mounton;
allow recovery fs_type:filesystem ~relabelto;
allow recovery unlabeled:filesystem ~relabelto;
allow recovery contextmount_type:filesystem relabelto;
# Create and relabel files and directories under /system.
allow recovery exec_type:{ file lnk_file } { create_file_perms relabelfrom relabelto };
allow recovery system_file:{ file lnk_file } { create_file_perms relabelfrom relabelto };
allow recovery system_file:dir { create_dir_perms relabelfrom relabelto };
# 0eb17d944704b3eb140bb9dded299d3be3aed77e in build/ added SELinux
# support to OTAs. However, that code has a bug. When an update occurs,
# some directories are inappropriately labeled as exec_type. This is
# only transient, and subsequent steps in the OTA script correct this
# mistake.
# Allow this behavior for now until we can fix the underlying bug.
# b/15575013
allow recovery exec_type:dir { create_dir_perms relabelfrom relabelto };
auditallow recovery exec_type:dir { create_dir_perms relabelfrom relabelto };
# Write to /proc/sys/vm/drop_caches
# TODO: create more specific label?
allow recovery proc:file w_file_perms;
# Write to /sys/class/android_usb/android0/enable.
# TODO: create more specific label?
allow recovery sysfs:file w_file_perms;
# Access /dev/android_adb.
allow recovery adb_device:chr_file rw_file_perms;
# Required to e.g. wipe userdata/cache.
allow recovery device:dir r_dir_perms;
allow recovery block_device:dir r_dir_perms;
allow recovery dev_type:blk_file rw_file_perms;
# GUI
allow recovery self:process execmem;
allow recovery ashmem_device:chr_file execute;
allow recovery graphics_device:chr_file rw_file_perms;
allow recovery graphics_device:dir r_dir_perms;
allow recovery input_device:dir r_dir_perms;
allow recovery input_device:chr_file r_file_perms;
allow recovery tty_device:chr_file rw_file_perms;
# Create /tmp/recovery.log and execute /tmp/update_binary.
allow recovery tmpfs:file { create_file_perms x_file_perms };
allow recovery tmpfs:dir create_dir_perms;
# Manage files on /cache
allow recovery cache_file:dir create_dir_perms;
allow recovery cache_file:file create_file_perms;
# Reboot the device
allow recovery powerctl_prop:property_service set;
unix_socket_connect(recovery, property, init)
# Use setfscreatecon() to label files for OTA updates.
allow recovery self:process setfscreate;
wakelock_use(recovery)
# This line seems suspect, as it should not really need to
# set scheduling parameters for a kernel domain task.
allow recovery kernel:process setsched;
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