4c6b13508d
The kernel, when it creates a loop block device, starts a new
kernel thread "loop0" (drivers/block/loop.c). This kernel thread,
which performs writes on behalf of other processes, needs read/write
privileges to the sdcard. Allow it.
Steps to reproduce:
0) Get device with external, removable sdcard
1) Run: "adb install -s foo.apk"
Expected:
APK installs successfully.
Actual:
APK fails to install. Error message:
Vold E Failed to write superblock (I/O error)
loop0 W type=1400 audit(0.0:3123): avc: denied { read } for path="/mnt/secure/asec/smdl1645334795.tmp.asec" dev="mmcblk1p1" ino=528 scontext=u:r:kernel:s0 tcontext=u:object_r:vfat:s0 tclass=file permissive=0
PackageHelper E Failed to create secure container smdl1645334795.tmp
DefContainer E Failed to create container smdl1645334795.tmp
Bug: 17158723
Change-Id: I4aa86e372cc55348f6b8becfa17bd4da583925d4
61 lines
2.2 KiB
Plaintext
61 lines
2.2 KiB
Plaintext
# Life begins with the kernel.
|
|
type kernel, domain;
|
|
|
|
# Run /init before we have switched domains.
|
|
allow kernel rootfs:file execute_no_trans;
|
|
|
|
# setcon to init domain.
|
|
allow kernel self:process setcurrent;
|
|
allow kernel init:process dyntransition;
|
|
|
|
# The kernel is unconfined.
|
|
unconfined_domain(kernel)
|
|
|
|
# cgroup filesystem initialization prior to setting the cgroup root directory label.
|
|
allow kernel unlabeled:dir search;
|
|
|
|
# Mount usbfs.
|
|
allow kernel usbfs:filesystem mount;
|
|
|
|
# init direct restorecon calls prior to switching to init domain
|
|
# /dev and /dev/socket
|
|
allow kernel { device socket_device }:dir relabelto;
|
|
# /dev/__properties__
|
|
allow kernel properties_device:file relabelto;
|
|
# /sys
|
|
allow kernel sysfs:{ dir file lnk_file } relabelfrom;
|
|
allow kernel sysfs_type:{ dir file lnk_file } relabelto;
|
|
|
|
# Initial setenforce by init prior to switching to init domain.
|
|
# We use dontaudit instead of allow to prevent a kernel spawned userspace
|
|
# process from turning off SELinux once enabled.
|
|
dontaudit kernel self:security setenforce;
|
|
|
|
# Set checkreqprot by init.rc prior to switching to init domain.
|
|
allow kernel self:security setcheckreqprot;
|
|
|
|
# MTP sync (b/15835289)
|
|
# kernel thread "loop0", used by the loop block device, for ASECs (b/17158723)
|
|
allow kernel sdcard_type:file { read write };
|
|
|
|
###
|
|
### neverallow rules
|
|
###
|
|
|
|
# The initial task starts in the kernel domain (assigned via
|
|
# initial_sid_contexts), but nothing ever transitions to it.
|
|
neverallow domain kernel:process { transition dyntransition };
|
|
|
|
# The kernel domain is never entered via an exec, nor should it
|
|
# ever execute a program outside the rootfs without changing to another domain.
|
|
# If you encounter an execute_no_trans denial on the kernel domain, then
|
|
# possible causes include:
|
|
# - The program is a kernel usermodehelper. In this case, define a domain
|
|
# for the program and domain_auto_trans() to it.
|
|
# - You failed to setcon u:r:init:s0 in your init.rc and thus your init
|
|
# program was left in the kernel domain and is now trying to execute
|
|
# some other program. Fix your init.rc file.
|
|
# - You are running an exploit which switched to the init task credentials
|
|
# and is then trying to exec a shell or other program. You lose!
|
|
neverallow kernel { file_type fs_type -rootfs }:file { entrypoint execute_no_trans };
|