These APIs expose sensitive information via timing side channels. This
leaves access via the adb shell intact along with the current uses by
dumpstate, init and system_server.

The /proc/interrupts and /proc/stat files were covered in this paper:

https://www.lightbluetouchpaper.org/2016/07/29/yet-another-android-side-channel/

The /proc/softirqs, /proc/timer_list and /proc/timer_stats files are
also relevant.

Access to /proc has been greatly restricted since then, with untrusted
apps no longer having direct access to these, but stricter restrictions
beyond that would be quite useful.

Change-Id: Ibed16674856569d26517e5729f0f194b830cfedd

Change-Id: I4c318efba76e61b6ab0be9491c352f281b1c2bff
Bug: 19160983

Since there is "write /proc/sys/vm/overcommit_memory 1" line in init.rc

Change-Id: I5899d2802e7fa56b438a06d4cadb4eb6827bfe16
Signed-off-by: Yongqin Liu <yongqin.liu@linaro.org>

Since kernel 4.1 ftrace is supported as a new separate filesystem. It
gets automatically mounted by the kernel under the old path
/sys/kernel/debug/tracing. Because it lives now on a separate device
some sepolicy rules need to be updated. This patch is doing that. Most
of the rules are created based on a conversation happened on the SELinux
Android mailing list:

http://comments.gmane.org/gmane.comp.security.seandroid/2799



Note, that this also needs 3a343a1 from the 4.4 branch in kernel/common.
Also note that when tracefs is auto mounted by the kernel, the kernel
does not use the "mode" parameter specified to mount debugfs for
tracefs. So an extra line like

   chmod 0755 /sys/kernel/debug/tracing

is necessary in init.${ro.hardware}.rc after debugfs was mounted.

Change-Id: I60fb7a90e24628e0370c3bca57644451fce5646d
Signed-off-by: Christian Poetzsch <christian.potzsch@imgtec.com>

avc: denied { read } for name="device" dev="sysfs" ino=36099 scontext=u:r:init:s0 tcontext=u:object_r:sysfs_rmtfs:s0 tclass=lnk_file

init is already allowed to read directories, this is an obvious omission.

Change-Id: I5131a84bb67e73aaed235c3cbab95c365eaaa2f0

Change-Id: Idaf59ab51f7873d4d75969c5f4e62b5fbf608ef5
Signed-off-by: William Roberts <william.c.roberts@intel.com>

Some of the init allow rules were well passed 100 characters and
were difficult to read. Format them to use the one-per-line
set subtraction format as seen in other locations within sepolicy.

Change-Id: Ifeeb3a8a81c4c19bfb1e56e7f2493f817e896eaf
Signed-off-by: William Roberts <william.c.roberts@intel.com>

Followup to 121f5bfd.

Move misc_logd_file neverallow rule from domain.te to logd.te,
since the goal of the neverallow rule is to protect logd / logpersist
files from other processes.

Switch the misc_logd_file neverallow rule from using "rw_file_perms"
to "no_rw_file_perms". The latter covers more cases of file
modifications.

Add more neverallow rules covering misc_logd_file directories.

Instead of using not_userdebug_nor_eng(), modify the rules to be
consistent with other highly constrained file types such as
keystore_data_file or vold_data_file. See, for example,
https://android-review.googlesource.com/144768

To see the net effect of this change, you can use the following
command line:

  sesearch --allow -t misc_logd_file -c file,dir,lnk_file \
  out/target/product/bullhead/root/sepolicy

Before this change:

  # userdebug builds
  allow init misc_logd_file:dir { search setattr read create getattr write relabelfrom ioctl rmdir remove_name relabelto open add_name };
  allow init misc_logd_file:file { setattr read create write relabelfrom getattr relabelto unlink open };
  allow init misc_logd_file:lnk_file { setattr relabelfrom create getattr relabelto unlink };
  allow logd misc_logd_file:dir { search read lock getattr write ioctl remove_name open add_name };
  allow logd misc_logd_file:file { rename setattr read lock create getattr write ioctl unlink open append };
  allow shell misc_logd_file:dir { search read lock getattr ioctl open };
  allow shell misc_logd_file:file { read lock ioctl open getattr };

  # user builds
  allow init misc_logd_file:dir { search setattr read create getattr write relabelfrom ioctl rmdir remove_name relabelto open add_name };
  allow init misc_logd_file:file relabelto;
  allow init misc_logd_file:lnk_file { setattr relabelfrom create getattr relabelto unlink };

After this change:

  # userdebug builds
  allow init misc_logd_file:dir { search setattr read create getattr ioctl relabelto open };
  allow init misc_logd_file:file { relabelto getattr };
  allow init misc_logd_file:lnk_file relabelto;
  allow logd misc_logd_file:dir { search read lock getattr write ioctl remove_name open add_name };
  allow logd misc_logd_file:file { rename setattr read lock create getattr write ioctl unlink open append };
  allow shell misc_logd_file:dir { search read lock getattr ioctl open };
  allow shell misc_logd_file:file { read lock ioctl open getattr };

  # user builds
  allow init misc_logd_file:dir { search setattr read create getattr ioctl relabelto open };
  allow init misc_logd_file:file { relabelto getattr };
  allow init misc_logd_file:lnk_file relabelto;

Change-Id: I0b00215049ad83182f458b4b9e258289c5144479

03-25 09:31:22.996     1     1 W init    : type=1400 audit(0.0:8): \
  avc: denied { getattr } for path="/data/misc/logd/logcat.052" \
  dev="dm-2" ino=124778 scontext=u:r:init:s0 \
  tcontext=u:object_r:misc_logd_file:s0 tclass=file permissive=0
. . .

Introduced a new macro not_userdebug_nor_eng()

Change-Id: I9c3a952c265cac096342493598fff7d41604ca45

Remove references to /data/security and the corresponding
type securitly_file.

Bug: 26544104
Change-Id: Iac00c293daa6b781a24c2bd4c12168dfb1cceac6

When using the A/B updater, a device specific hook is sometimes needed
to run after the new partitions are updated but before rebooting into
the new image. This hook is referred to throughout the code as the
"postinstall" step.

This patch creates a new execution domain "postinstall" which
update_engine will use to run said hook. Since the hook needs to run
from the new image (namelly, slot "B"), update_engine needs to
temporarly mount this B partition into /postinstall and then run a
program from there.

Since the new program in B runs from the old execution context in A, we
can't rely on the labels set in the xattr in the new filesystem to
enforce the policies baked into the old running image. Instead, when
temporarily mounting the new filesystem in update_engine, we override
all the new file attributes with the new postinstall_file type by
passing "context=u:object_r:postinstall_file:s0" to the mount syscall.
This allows us to set new rules specific to the postinstall environment
that are consistent with the rules in the old system.

Bug: 27177071
TEST=Deployed a payload with a trivial postinstall script to edison-eng.

Change-Id: Ib06fab92afb45edaec3c9c9872304dc9386151b4

Since linux 3.18, commit 68c4a4f8abc60c9440ede9cd123d48b78325f7a3 has
been integrated and requires syslog_read capability a process accessing
console-ramoops file.

sepolicy must be adapted to this new requirement.

Change-Id: Ib4032a6bd96b1828a0154edc8fb510e3c1d3bdc2
Signed-off-by: Sylvain Chouleur <sylvain.chouleur@intel.com>

This will allow init to terminate services cleanly (SIGTERM, wait,
SIGKILL) when needed.

Bug: 26216447
Test: manual: init is able to send a SIGTERM signal without denials.

Change-Id: Id2471ca08c0b011be64a36956628e965bc999bc6

Address following denials:
avc: denied { getattr } for path="/sys/devices/virtual/block/zram0/disksize" dev="sysfs" ino=14958 scontext=u:r:init:s0 tcontext=u:object_r:sysfs_zram:s0 tclass=file permissive=0
avc: denied { search } for name="zram0" dev="sysfs" ino=14903 scontext=u:r:system_server:s0 tcontext=u:object_r:sysfs_zram:s0 tclass=dir permissive=0
avc: denied { read } for name="mem_used_total" dev="sysfs" ino=14970 scontext=u:r:system_server:s0 tcontext=u:object_r:sysfs_zram:s0 tclass=file permissive=0
avc: denied { write } for name="uevent" dev="sysfs" ino=14904 scontext=u:r:ueventd:s0 tcontext=u:object_r:sysfs_zram:s0 tclass=file permissive=0
avc: denied { open } for path="/sys/devices/virtual/block/zram0/uevent" dev="sysfs" ino=14904 scontext=u:r:ueventd:s0 tcontext=u:object_r:sysfs_zram:s0 tclass=file permissive=0
avc: denied { read } for pid=348 comm="vold" name="zram0" dev="sysfs" ino=15223 scontext=u:r:vold:s0 tcontext=u:object_r:sysfs_zram:s0 tclass=dir permissive=0
avc: denied { search } for pid=3494 comm="ContactsProvide" name="zram0"dev="sysfs" ino=15223 scontext=u:r:priv_app:s0:c512,c768 tcontext=u:object_r:sysfs_zram:s0 tclass=dir permissive=0

Bug: 22032619
Change-Id: I40cf918b7cafdba6cb3d42b04b1616a84e4ce158

Needed to disable tracing. See frameworks/native/cmds/atrace/atrace.rc

Also allow shell getattr access to the tracing file. That way
"ls -la" returns something meaningful.

Bug: 26217098
Change-Id: I4eee1aff1127db8945612133c8ae16c34cfbb786

Add initial support for labeling files on /sys/kernel/debug.
The kernel support was added in https://android-review.googlesource.com/122130
but the userspace portion of the change was never completed until now.

Start labeling the file /sys/kernel/debug/tracing/trace_marker . This
is the trace_marker file, which is written to by almost all processes
in Android. Allow global write access to this file.

This change should be submitted at the same time as the system/core
commit with the same Change-Id as this patch.

Change-Id: Id1d6a9ad6d0759d6de839458890e8cb24685db6d

Properties are now broken up from a single /dev/__properties__ file into
multiple files, one per property label.  This commit provides the
mechanism to control read access to each of these files and therefore
sets of properties.

This allows full access for all domains to each of these new property
files to match the current permissions of /dev/__properties__.  Future
commits will restrict the access.

Bug: 21852512

Change-Id: Ie9e43968acc7ac3b88e354a0bdfac75b8a710094

Change-Id: I08aaf89e2ef23f9528d107a1c9d66c1c9979b3ac

Motivation: Domain is overly permissive. Start removing permissions
from domain and assign them to the domain_deprecated attribute.
Domain_deprecated and domain can initially be assigned to all
domains. The goal is to not assign domain_deprecated to new domains
and to start removing domain_deprecated where it is not required or
reassigning the appropriate permissions to the inheriting domain
when necessary.

Bug: 25433265
Change-Id: I8b11cb137df7bdd382629c98d916a73fe276413c

For userdebug and eng builds enforce that:

 - only logd and shell domains may access logd files

 - logd is only allowed to write to /data/misc/logd

Change-Id: Ie909cf701fc57109257aa13bbf05236d1777669a

Revert the neverallow change portion of
356df327, in case others need to
do dynamic policy updates.

(cherrypicked from commit e827a8ab)

Bug: 22885422
Bug: 8949824
Change-Id: If0745e7f83523377fd19082cfc6b33ef47ca0647

Remove the ability to dynamically update SELinux policy on the
device.

1) This functionality has never been used, so we have no idea if
it works or not.

2) If system_server is compromised, this functionality allows a
complete bypass of the SELinux policy on the device. In particular,
an attacker can force a regression of the following patch
  * https://android-review.googlesource.com/138510
see also https://code.google.com/p/android/issues/detail?id=181826

3) Dynamic policy update can be used to bypass neverallow protections
enforced in CTS, by pushing a policy to the device after certification.
Such an updated policy could bring the device out of compliance or
deliberately introduce security weaknesses.

(cherrypicked from commit e827a8ab)

Bug: 22885422
Bug: 8949824
Change-Id: I802cb61fd18a452a2bb71c02fe57cfce5b7e9dc8

Add a neverallow rule (compile time assertion) for /data/local/tmp
access. /data/local/tmp is intended entirely for the shell user, and
it's dangerous for other SELinux domains to access it. See, for example,
this commit from 2012:

  https://android.googlesource.com/platform/system/core/+/f3ef1271f225d9f00bb4ebb0573eb3e03829f9a8

Change-Id: I5a7928ae2b51a574fad4e572b09e60e05b121cfe

Revert the neverallow change portion of
356df327, in case others need to
do dynamic policy updates.

Bug: 22885422
Bug: 8949824
Change-Id: If2c13d112b346db5c011a6a61bc4486b43d46d61

Remove the ability to dynamically update SELinux policy on the
device.

1) This functionality has never been used, so we have no idea if
it works or not.

2) If system_server is compromised, this functionality allows a
complete bypass of the SELinux policy on the device. In particular,
an attacker can force a regression of the following patch
  * https://android-review.googlesource.com/138510
see also https://code.google.com/p/android/issues/detail?id=181826

3) Dynamic policy update can be used to bypass neverallow protections
enforced in CTS, by pushing a policy to the device after certification.
Such an updated policy could bring the device out of compliance or
deliberately introduce security weaknesses.

Bug: 22885422
Bug: 8949824
Change-Id: Id98b5e09d79254816d920b92003efe8dcbe6cd2e

Change-Id: I08aaf89e2ef23f9528d107a1c9d66c1c9979b3ac

Init never uses / add service manager services. It doesn't make
sense to allow these rules to init. Adding a rule of this type
is typically caused by a process inappropriately running in init's
SELinux domain, and the warning message:

  Warning!  Service %s needs a SELinux domain defined; please fix!

is ignored.

In addition, add neverallow rules to domain.te which prevent
nonsense SELinux service_manager rules from being added.

Change-Id: Id04a50d1826fe451a9ed216aa7ab249d0393cc57

(cherry pick from commit 0d22c6ce)

- Enable logpersistd to write to /data/misc/logd
- Enable logpersistd to read from pstore to help complete any content
  lost by reboot disruption
- Enable shell readonly ability logpersistd files in /data/misc/logd
- Enable logcat -f when placed into logd context to act as a
  logpersistd (nee logcatd) agent, restrict access to run only in
  userdebug or eng

Bug: 19608716
Change-Id: I3209582bc796a1093c325c90068a48bf268e5ab5

- Enable logpersistd to write to /data/misc/logd
- Enable logpersistd to read from pstore to help complete any content
  lost by reboot disruption
- Enable shell readonly ability logpersistd files in /data/misc/logd
- Enable logcat -f when placed into logd context to act as a
  logpersistd (nee logcatd) agent, restrict access to run only in
  userdebug or eng

Bug: 19608716
Change-Id: I3209582bc796a1093c325c90068a48bf268e5ab5

(cherry-picked from change f7163597)

This is one of three changes to enable this functionality:
  https://android-review.googlesource.com/#/c/146259/
  https://android-review.googlesource.com/#/c/146264/
  https://android-review.googlesource.com/#/c/146265/

Bug: 18151196

Change-Id: I6ce4bc977a548df93ea5c09430f93eef5ee1f9fa

(chery-picked from commit 13dec5fa)

Move all key management into vold
Reuse vold's existing key management through the crypto footer
to manage the device wide keys.

Use ro.crypto.type flag to determine crypto type, which prevents
any issues when running in block encrypted mode, as well as speeding
up boot in block or no encryption.

This is one of four changes to enable this functionality:
  https://android-review.googlesource.com/#/c/148586/
  https://android-review.googlesource.com/#/c/148604/
  https://android-review.googlesource.com/#/c/148606/
  https://android-review.googlesource.com/#/c/148607/

Bug: 18151196

Change-Id: I3208b76147df9da83d34cf9034675b0689b6c3a5

This is one of three changes to enable this functionality:
  https://android-review.googlesource.com/#/c/146259/
  https://android-review.googlesource.com/#/c/146264/
  https://android-review.googlesource.com/#/c/146265/

Bug: 18151196

Change-Id: I6ce4bc977a548df93ea5c09430f93eef5ee1f9fa

Move all key management into vold
Reuse vold's existing key management through the crypto footer
to manage the device wide keys.

Use ro.crypto.type flag to determine crypto type, which prevents
any issues when running in block encrypted mode, as well as speeding
up boot in block or no encryption.

This is one of four changes to enable this functionality:
  https://android-review.googlesource.com/#/c/148586/
  https://android-review.googlesource.com/#/c/148604/
  https://android-review.googlesource.com/#/c/148606/
  https://android-review.googlesource.com/#/c/148607/

Bug: 18151196

Change-Id: I3208b76147df9da83d34cf9034675b0689b6c3a5

This reverts commit 5287d9a8.

Change-Id: I9ec0db0718da7088dc2b66f5b1749b8fb069575a

This change removes the link, but moves key management to
vold, so we need to adjust permissions alternately.

This is one of four changes to enable this functionality:
  https://android-review.googlesource.com/#/c/144586/
  https://android-review.googlesource.com/#/c/144663/
  https://android-review.googlesource.com/#/c/144672/
  https://android-review.googlesource.com/#/c/144673/

Bug: 18151196
Change-Id: I58d3200ae0837ccdf1b8d0d6717566a677974cf1

Don't allow init to mount on top of /proc. See
https://android-review.googlesource.com/148295 for details.

Change-Id: I65f66b39f3a5bfb72facb9f716f4537ac2237af1

This reverts commit c450759e.

There was nothing wrong with this change originally --- the companion
change in init was broken.

Bug: http://b/19702273
Change-Id: I9d806f6ac251734a61aa90c0741bec7118ea0387

shamu isn't booting.

This reverts commit 46e832f5.

Change-Id: Ib697745a9a1618061bc72f8fddd7ee88c1ac5eca

Change-Id: I5eca4f1f0f691be7c25e463563e0a4d2ac737448

Creates new directory at /data/misc/vold for storing key material
on internal storage.  Only vold should have access to this label.

Change-Id: I7f2d1314ad3b2686e29e2037207ad83d2d3bf465