Commit Graph

7 Commits

Author SHA1 Message Date
Nick Kralevich
5e37271df8 Introduce system_file_type
system_file_type is a new attribute used to identify files which exist
on the /system partition. It's useful for allow rules in init, which are
based off of a blacklist of writable files. Additionally, it's useful
for constructing neverallow rules to prevent regressions.

Additionally, add commented out tests which enforce that all files on
the /system partition have the system_file_type attribute. These tests
will be uncommented in a future change after all the device-specific
policies are cleaned up.

Test: Device boots and no obvious problems.
Change-Id: Id9bae6625f042594c8eba74ca712abb09702c1e5
2018-09-27 12:52:09 -07:00
Jeff Vander Stoep
7a4af30b38 Start the process of locking down proc/net
Files in /proc/net leak information. This change is the first step in
determining which files apps may use, whitelisting benign access, and
otherwise removing access while providing safe alternative APIs.

To that end, this change:
* Introduces the proc_net_type attribute which will assigned to any
new SELinux types in /proc/net to avoid removing access to privileged
processes. These processes may be evaluated later, but are lower
priority than apps.
* Labels /proc/net/{tcp,tcp6,udp,udp6} as proc_net_vpn due to existing
use by VPN apps. This may be replaced by an alternative API.
* Audits all other proc/net access for apps.
* Audits proc/net access for other processes which are currently
granted broad read access to /proc/net but should not be including
storaged, zygote, clatd, logd, preopt2cachename and vold.

Bug: 9496886
Bug: 68016944
Test: Boot Taimen-userdebug. On both wifi and cellular: stream youtube
    navigate maps, send text message, make voice call, make video call.
    Verify no avc "granted" messages in the logs.
Test: A few VPN apps including "VPN Monster", "Turbo VPN", and
"Freighter". Verify no logspam with the current setup.
Test: atest CtsNativeNetTestCases
Test: atest netd_integration_test
Test: atest QtaguidPermissionTest
Test: atest FileSystemPermissionTest

Change-Id: I7e49f796a25cf68bc698c6c9206e24af3ae11457
Merged-In: I7e49f796a25cf68bc698c6c9206e24af3ae11457
(cherry picked from commit 087318957f)
2018-05-04 21:36:33 +00:00
Benjamin Gordon
9b2e0cbeea sepolicy: Add rules for non-init namespaces
In kernel 4.7, the capability and capability2 classes were split apart
from cap_userns and cap2_userns (see kernel commit
8e4ff6f228e4722cac74db716e308d1da33d744f). Since then, Android cannot be
run in a container with SELinux in enforcing mode.

This change applies the existing capability rules to user namespaces as
well as the root namespace so that Android running in a container
behaves the same on pre- and post-4.7 kernels.

This is essentially:
  1. New global_capability_class_set and global_capability2_class_set
     that match capability+cap_userns and capability2+cap2_userns,
     respectively.
  2. s/self:capability/self:global_capability_class_set/g
  3. s/self:capability2/self:global_capability2_class_set/g
  4. Add cap_userns and cap2_userns to the existing capability_class_set
     so that it covers all capabilities.  This set was used by several
     neverallow and dontaudit rules, and I confirmed that the new
     classes are still appropriate.

Test: diff new policy against old and confirm that all new rules add
      only cap_userns or cap2_userns;
      Boot ARC++ on a device with the 4.12 kernel.
Bug: crbug.com/754831

Change-Id: I4007eb3a2ecd01b062c4c78d9afee71c530df95f
2017-11-21 08:34:32 -07:00
Jeff Vander Stoep
76aab82cb3 Move domain_deprecated into private policy
This attribute is being actively removed from policy. Since
attributes are not being versioned, partners must not be able to
access and use this attribute. Move it from private and verify in
the logs that rild and tee are not using these permissions.

Bug: 38316109
Test: build and boot Marlin
Test: Verify that rild and tee are not being granted any of these
      permissions.
Change-Id: I31beeb5bdf3885195310b086c1af3432dc6a349b
2017-05-15 13:37:59 -07:00
Jeff Vander Stoep
f627e5581c restore permissions to /vendor for non-treble devices
Relabeling /vendor and /system/vendor to vendor_file removed
previously granted permissions. Restore these for non-treble devices.

Addresses:
avc: denied { execute_no_trans } for pid=2944 comm="dumpstate"
path="/system/vendor/bin/wpa_cli" dev="mmcblk0p10" ino=1929
scontext=u:r:dumpstate:s0 tcontext=u:object_r:vendor_file:s0
tclass=file

And potentially some other bugs that have yet to surface.

Bug: 37105075
Test: build Fugu
Change-Id: I8e7bd9c33819bf8206f7c110cbce72366afbcef8
2017-04-14 10:01:14 -07:00
Jeff Vander Stoep
50563c0367 Ban core components from accessing vendor data types
Vendor and system components are only allowed to share files by
passing open FDs over HIDL. Ban all directory access and all file
accesses other than what can be applied to an open FD such as
ioctl/stat/read/write/append.

This commit asserts that core components marked with attribute
coredomain may only access core data types marked with attribute
core_data_file_type.

A temporary exemption is granted to domains that currently rely on
access.

(cherry picked from commit cd97e71084)

Bug: 34980020
Test: build Marlin policy
Change-Id: I2f0442f2628fbac1f2f7aa5ddf2a13e16b2546cc
2017-04-01 07:16:40 -07:00
dcashman
cc39f63773 Split general policy into public and private components.
Divide policy into public and private components.  This is the first
step in splitting the policy creation for platform and non-platform
policies.  The policy in the public directory will be exported for use
in non-platform policy creation.  Backwards compatibility with it will
be achieved by converting the exported policy into attribute-based
policy when included as part of the non-platform policy and a mapping
file will be maintained to be included with the platform policy that
maps exported attributes of previous versions to the current platform
version.

Eventually we would like to create a clear interface between the
platform and non-platform device components so that the exported policy,
and the need for attributes is minimal.  For now, almost all types and
avrules are left in public.

Test: Tested by building policy and running on device.

Change-Id: Idef796c9ec169259787c3f9d8f423edf4ce27f8c
2016-10-06 13:09:06 -07:00