Motivation:
Provide the ability to phase in new security policies by
applying them to apps with a minimum targetSdkVersion.
Place untrusted apps with targetSdkVersion<=25 into the
untrustd_app_25 domain. Apps with targetSdkVersion>=26 are placed
into the untrusted_app domain. Common rules are included in the
untrusted_app_all attribute. Apps with a more recent targetSdkVersion
are granted fewer permissions.
Test: Marlin builds and boots. Apps targeting targetSdkVersion<=25
run in untrusted_app_25 domain. Apps targeting the current development
build >=26 run in the untrusted_app domain with fewer permissions. No
new denials observed during testing.
Bug: 34115651
Bug: 35323421
Change-Id: Ie6a015566fac07c44ea06c963c40793fcdc9a083
The rules for the two types were the same and /data/app-ephemeral is
being removed. Remove these types.
Test: Builds
Change-Id: I520c026395551ad1362dd2ced53c601d9e6f9b28
There are many character files that are unreachable to all processes
under selinux policies. Ueventd and init were the only two domains that
had access to these generic character files, but auditing proved there
was no use for that access. In light of this, access is being completely
revoked so that the device nodes can be removed, and a neverallow is
being audited to prevent future regressions.
Test: The device boots
Bug: 33347297
Change-Id: If050693e5e5a65533f3d909382e40f9c6b85f61c
Since it was introduced it caused quite a few issues and it spams the
SElinux logs unnecessary.
The end goal of the audit was to whitelist the access to the
interpreter. However that's unfeasible for now given the complexity.
Test: devices boots and everything works as expected
no more auditallow logs
Bug: 29795519
Bug: 32871170
Change-Id: I9a7a65835e1e1d3f81be635bed2a3acf75a264f6
This neverallow addition addresses the renaming of files in exploits in
order to bypass denied permissions. An example of a similar use case of
using mv to bypass permission denials appeared in a recent project zero
ChromeOS exploit as one of the steps in the exploit chain.
https://googleprojectzero.blogspot.com/2016/12/chrome-os-exploit-one-byte-overflow-and.html
Additionally, vold and init both had permission sets that allowed them
to rename, but neither of them seem to need it. Therefore the rename
permission has also been removed from these two .te files.
Test: The device boots successfully
Change-Id: I07bbb58f058bf050f269b083e836c2c9a5bbad80
As of https://android-review.googlesource.com/324092, ephemeral_app is
now an appdomain, so places where both appdomain and ephemeral_app are
granted the same set of rules can be deleted.
Test: policy compiles.
Change-Id: Ideee710ea47af7303e5eb3af1331653afa698415
Replace the global debuggerd with a per-process debugging helper that
gets exec'ed by the process that crashed.
Bug: http://b/30705528
Test: crasher/crasher64, `debuggerd <pid>`, `kill -ABRT <pid>`
Change-Id: Iad1b7478f7a4e2690720db4b066417d8b66834ed
Don't allow processes to list out the contents of the directory
/dev/__properties__. This is an implementation specific detail that
shouldn't be visible to processes.
Test: Device boots and no problems reading individual properties.
Test: ls -la /dev/__properties__ fails
Change-Id: I4df6a829b0d22e30fb2c38030c690fc4a356f6a3
6e4508e625 inadvertently removed access
to ro.serialno and ro.boot.serialno from ADB shell. This is needed for
CTS. This commit thus reinstates the access.
Test: adb shell getprop ro.serialno
Bug: 33700679
Change-Id: I62de44b1631c03fcd64ceabaf33bbaeb869c2851
ro.runtime.firstboot system property is only used internally by
system_server to distinguish between first start after boot from
consecutive starts (for example, this happens when full-disk
encryption is enabled). The value of the property is a
millisecond-precise timestamp which can help track individual
device. Thus apps should not have access to this property.
Test: Device boots fine, reading ro.runtime.firstboot from an app results in an error and SELinux denial.
Bug: 33700679
Change-Id: I4c3c26a35c5dd840bced3a3e53d071f45317f63c
This restricts access to ro.serialno and ro.boot.serialno, the two
system properties which contain the device's serial number, to a
select few SELinux domains which need the access. In particular, this
removes access to these properties from Android apps. Apps can access
the serial number via the public android.os.Build API. System
properties are not public API for apps.
The reason for the restriction is that serial number is a globally
unique identifier which cannot be reset by the user. Thus, it can be
used as a super-cookie by apps. Apps need to wean themselves off of
identifiers not resettable by the user.
Test: Set up fresh GMS device, install some apps via Play, update some apps, use Chrome
Test: Access the device via ADB (ADBD exposes serial number)
Test: Enable MTP over USB, use mtp-detect to confirm that serial number is reported in MTP DeviceInfo
Bug: 31402365
Bug: 33700679
Change-Id: I4713133b8d78dbc63d8272503e80cd2ffd63a2a7
Add a compile time assertion that only authorized SELinux domains are
allowed to touch the metadata_block_device. This domain may be wiped at
will, and we want to ensure that we're not inadvertently destroying
other people's data.
Test: policy compiles.
Change-Id: I9854b527c3d83e17f717d6cc8a1c6b50e0e373b6
In order to support platform changes without simultaneous updates from
non-platform components, the platform and non-platform policies must be
split. In order to provide a guarantee that policy written for
non-platform objects continues to provide the same access, all types
exposed to non-platform policy are versioned by converting them and the
policy using them into attributes.
This change performs that split, the subsequent versioning and also
generates a mapping file to glue the different policy components
together.
Test: Device boots and runs.
Bug: 31369363
Change-Id: Ibfd3eb077bd9b8e2ff3b2e6a0ca87e44d78b1317
Broke the dragon build:
libsepol.report_failure: neverallow on line 304 of system/sepolicy/public/domain.te (or line 8638 of policy.conf) violated by allow kernel device:chr_file { create setattr };
libsepol.check_assertions: 1 neverallow failures occurred
Error while expanding policy
This reverts commit ed0b4eb366.
Change-Id: I5d55ab59ed72ce7c19a10ddbb374f9f3b3fae4fd
By default, files created in /dev are labeled with the "device" label
unless a different label has been assigned. The direct use of this
generic label is discouraged (and in many cases neverallowed) because
rules involving this label tend to be overly broad and permissive.
Today, generically labeled character devices can only be opened, read,
or written to by init and ueventd.
$ sesearch --allow -t device -c chr_file -p open,read,write out/target/product/marlin/root/sepolicy
allow init device:chr_file { setattr read lock getattr write ioctl open append };
allow ueventd device:chr_file { read lock getattr write ioctl open append };
this is enforced by the following SELinux neverallow rule (compile time
assertion + CTS test):
neverallow { domain -init -ueventd } device:chr_file { open read write };
Start auditallowing ueventd access to /dev character device files with the
default SELinux label. This doesn't appear to be used, but let's prove it.
While ueventd is expected to create files in /dev, it has no need to open
most of the files it creates.
Note, however, that because ueventd has mknod + setfscreate permissions,
a malicious or compromised ueventd can always create a device node under
an incorrect label, and gain access that way.
The goal of this change is to prove that no process other than init are
accessing generically labeled files in /dev.
While I'm here, tighten up the compile time assertion for
device:chr_file to include more permissions.
Test: policy compiles + device boots with no granted messages.
Change-Id: Ic98b0ddc631b49b09e58698d9f40738ccedd1fd0
Only init and ueventd have any access to /dev/port, and neither should
have any use for it. As it stands, leaving port in just represents
additional attack surface with no useful functionality, so it should be
removed if possible, not only from Pixel devices, but from all Android
devices.
Test: The phone boots successfully
Bug:33301618
Change-Id: Iedc51590f1ffda02444587d647889ead9bdece3f
urandom_device and random_device have the exact same security
properties. Collapse them into one type.
Test: device boots and /dev/urandom is labeled correctly.
Change-Id: I12da30749291bc5e37d99bc9422bb86cb58cec41
The other domains either don't have the same backwards compatibility
issues (isolated_app) or are privileged components that are pretty much
part of the platform and can be expected to meet a higher standard.
It would be possible to expose a build option for disabling the ART JIT,
allowing conditional removal of execmem from some of these domains too
(ones not ever using the WebView, until that's always in isolated_app).
Bug: 20013628
Change-Id: Ic22513157fc8b958b2a3d60381be0c07b5252fa5
The webview_zygote is a new unprivileged zygote and has its own sockets for
listening to fork requests. However the webview_zygote does not run as root
(though it does require certain capabilities) and only allows dyntransition to
the isolated_app domain.
Test: m
Test: angler boots
Bug: 21643067
Change-Id: I89a72ffe6dcb983c4a44048518efd7efb7ed8e83
The underlying ioctl denial was fixed in device-specific policy.
It's not needed in core policy.
A search of SELinux denials shows no reported denials, other than the
ones showing up on marlin.
This reverts commit ec3285cde0.
(cherrypicked from commit 863ce3e7c7)
Test: AndroiTS GPS Test app shows GPS data, no SELinux denials.
Bug: 32290392
Change-Id: I1ba7bad43a2cdd7cdebbe1c8543a71eee765621d
Filesystem capabilities should only be set by the build tools
or by recovery during an update. Place a neverallow ensuring
this property.
Change-Id: I136c5cc16dff0c0faa3799d0ab5e29b43454a610
Signed-off-by: William Roberts <william.c.roberts@intel.com>
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
