Linux defines two capabilities for Mandatory Access Control (MAC)
security modules, CAP_MAC_OVERRIDE (override MAC access restrictions)
and CAP_MAC_ADMIN (allow MAC configuration or state changes).
SELinux predates these capabilities and did not originally use them,
but later made use of CAP_MAC_ADMIN as a way to control the ability
to set security context values unknown to the currently loaded
SELinux policy on files.  That facility is used in Linux for e.g.
livecd creation where a file security context that is being set
on a generated filesystem is not known to the build host policy.
Internally, files with such labels are treated as having the unlabeled
security context for permission checking purposes until/unless the
context is later defined through a policy reload.

CAP_MAC_OVERRIDE is never checked by SELinux, so it never needs
to be allowed.  CAP_MAC_ADMIN is only checked if setting an
unknown security context value; the only legitimate use I can see
in Android is the recovery console, where a context may need to be set
on /system that is not defined in the recovery policy.

Remove these capabilities from unconfined domains, allow
mac_admin for the recovery domain, and add neverallow rules.

Change-Id: Ief673e12bc3caf695f3fb67cabe63e68f5f58150
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>

When adbd runs as root, it transitions into the
su domain. Add the various rules to support this.

This is needed to run the adbd and shell domains in
enforcing on userdebug / eng devices without breaking
developer workflows.

Change-Id: Ib33c0dd2dd6172035230514ac84fcaed2ecf44d6

powervr_device is obsoleted by the more general gpu_device.
akm_device and accelerometer_device are obsoleted by the more
general sensors_device.

We could also drop the file_contexts entries altogether and
take them to device-specific policy (in this case, they all
came from crespo, so that is obsolete for master).

Change-Id: I63cef43b0d66bc99b80b64655416cc050f443e7d
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>

We do not want to permit connecting to arbitrary unconfined services
left running in the init domain.  I do not know how this was originally
triggered and thus cannot test that it is fixed.  Possible causes:
- another service was left running in init domain, e.g. dumpstate,
- there was a socket entry for the service in the init.rc file
and the service was launched via logwrapper and therefore init did
not know how to label the socket.

The former should be fixed.  The latter can be solved either by
removing use of logwrapper or by specifying the socket context
explicitly in the init.rc file now.

Change-Id: I09ececaaaea2ccafb7637ca08707566c1155a298
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>

Just use notdevfile_class_set to pick up all non-device file classes.

Change-Id: Ib3604537ccfc25da67823f0f2b5d70b84edfaadf
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>

Otherwise all domains can create/write files that are executable
by all other domains.  If I understand correctly, this should
only be necessary for app domains executing content from legacy
unlabeled userdata partitions on existing devices and zygote
and system_server mappings of dalvikcache files, so only allow
it for those domains.

If required for others, add it to the individual
domain .te file, not for all domains.

Change-Id: I6f5715eb1ecf2911e70772b9ab4e531feea18819
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>

Now that we set /sys/fs/selinux/checkreqprot via init.rc,
restrict the ability to set it to only the kernel domain.

Change-Id: I975061fd0e69c158db9bdb23e6ba77948e3fead1
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>

/proc/sys/net could use its own type to help distinguish
among some of the proc access rules. Fix dhcp and netd
because of this.

Change-Id: I6e16cba660f07bc25f437bf43e1eba851a88d538
Signed-off-by: rpcraig <rpcraig@tycho.ncsc.mil>

init can't handle binder calls. It's always incorrect
to allow init:binder call, and represents a binder call
to a service without an SELinux domain. Adding this
allow rule was a mistake; the dumpstate SELinux domain didn't
exist at the time this rule was written, and dumpstate was
running under init's domain.

Add a neverallow rule to prevent the reintroduction of
this bug.

Change-Id: I78d35e675fd142d880f15329471778c18972bf50

Resolves the following denials seen during an adb backup and restore
sequence.

<5>[   90.247039] type=1400 audit(1388759567.693:16): avc:  denied  { getopt } for  pid=3503 comm="Thread-149" scontext=u:r:system_server:s0 tcontext=u:r:adbd:s0 tclass=unix_stream_socket
<5>[   90.249176] type=1400 audit(1388759567.703:17): avc:  denied  { getopt } for  pid=2334 comm="app_process" scontext=u:r:shell:s0 tcontext=u:r:adbd:s0 tclass=unix_stream_socket

Change-Id: I1f6f90f29eecc32ee692764b04b812988f099cde
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>

execmem permission controls the ability to make an anonymous
mapping executable or to make a private file mapping writable
and executable.  Remove this permission from domain (i.e.
all domains) by default, and add it explicitly to app domains.
It is already allowed in other specific .te files as required.
There may be additional cases in device-specific policy where
it is required for proprietary binaries.

Change-Id: I902ac6f8cf2e93d46b3a976bc4dabefa3905fce6
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>

Confine the domain for an adb shell in -user builds only.
The shell domain in non-user builds is left permissive.
init_shell (shell spawned by init, e.g.  console service)
remains unconfined by this change.
Introduce a shelldomain attribute for rules common to all shell
domains, assign it to the shell types, and add shelldomain.te for
its rules.

Change-Id: I01ee2c7ef80b61a9db151abe182ef9af7623c461
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>

And allow any SELinux domain to read these timezone
related files.

Addresses the following denial:
<5>[    4.746399] type=1400 audit(3430294.470:7): avc:  denied  { open } for  pid=197 comm="time_daemon" name="tzdata" dev="mmcblk0p28" ino=618992 scontext=u:r:time:s0 tcontext=u:object_r:system_data_file:s0 tclass=file

Change-Id: Iff32465e62729d7aad8c79607848d89ce0aede86

Remove init, ueventd, watchdogd, healthd and adbd from the set of
domains traceable by debuggerd.  bionic/linker/debugger.cpp sets up
handlers for all dynamically linked programs in Android but this
should not apply for statically linked programs.

Exclude ptrace access from unconfineddomain.

Prohibit ptrace access to init via neverallow.

Change-Id: I70d742233fbe40cb4d1772a4e6cd9f8f767f2c3a
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>

As per the discussion in:
https://android-review.googlesource.com/#/c/71184/



init sets the enforcing mode in its code prior to switching to
the init domain via a setcon command in the init.rc file.  Hence,
the setenforce permission is checked while still running in the
kernel domain.  Further, as init has no reason to ever set the
enforcing mode again, we do not need to allow setenforce to the
init domain and this prevents reverting to permissive
mode via an errant write by init later.  We could technically
dontaudit the kernel setenforce access instead since the first
call to setenforce happens while still permissive (and thus we
never need to allow it in policy) but we allow it to more accurately
represent what is possible.

Change-Id: I70b5e6d8c99e0566145b9c8df863cc8a34019284
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>

The build is broken. Reverting temporarily to fix breakage.

libsepol.check_assertion_helper: neverallow on line 4758 violated by allow init kernel:security { setenforce };
Error while expanding policy
make: *** [out/target/product/mako/obj/ETC/sepolicy_intermediates/sepolicy] Error 1
make: *** Waiting for unfinished jobs....


This reverts commit bf12e225.

Change-Id: I78a05756d8ce3c7d06e1d9d27e6135f4b352bb85

As per the discussion in:
https://android-review.googlesource.com/#/c/71184/



init sets the enforcing mode in its code prior to switching to
the init domain via a setcon command in the init.rc file.  Hence,
the setenforce permission is checked while still running in the
kernel domain.  Further, as init has no reason to ever set the
enforcing mode again, we do not need to allow setenforce to the
init domain and this prevents reverting to permissive
mode via an errant write by init later.  We could technically
dontaudit the kernel setenforce access instead since the first
call to setenforce happens while still permissive (and thus we
never need to allow it in policy) but we allow it to more accurately
represent what is possible.

Change-Id: I617876c479666a03167b8fce270c82a8d45c7cc6
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>

Limit the ability to write to the files that configure kernel
usermodehelpers and security-sensitive proc settings to the init domain.
Permissive domains can also continue to set these values.

The current list is not exhaustive, just an initial set.
Not all of these files will exist on all kernels/devices.
Controlling access to certain kernel usermodehelpers, e.g. cgroup
release_agent, will require kernel changes to support and cannot be
addressed here.

Expected output on e.g. flo after the change:
ls -Z /sys/kernel/uevent_helper /proc/sys/fs/suid_dumpable /proc/sys/kernel/core_pattern /proc/sys/kernel/dmesg_restrict /proc/sys/kernel/hotplug /proc/sys/kernel/kptr_restrict /proc/sys/kernel/poweroff_cmd /proc/sys/kernel/randomize_va_space /proc/sys/kernel/usermodehelper
-rw-r--r-- root     root              u:object_r:usermodehelper:s0 uevent_helper
-rw-r--r-- root     root              u:object_r:proc_security:s0 suid_dumpable
-rw-r--r-- root     root              u:object_r:usermodehelper:s0 core_pattern
-rw-r--r-- root     root              u:object_r:proc_security:s0 dmesg_restrict
-rw-r--r-- root     root              u:object_r:usermodehelper:s0 hotplug
-rw-r--r-- root     root              u:object_r:proc_security:s0 kptr_restrict
-rw-r--r-- root     root              u:object_r:usermodehelper:s0 poweroff_cmd
-rw-r--r-- root     root              u:object_r:proc_security:s0 randomize_va_space
-rw------- root     root              u:object_r:usermodehelper:s0 bset
-rw------- root     root              u:object_r:usermodehelper:s0 inheritable

Change-Id: I3f24b4bb90f0916ead863be6afd66d15ac5e8de0
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>

This label was originally used for Motorola
Xoom devices. nvmap is the tegra gpu memory
manager and the various nvhost drivers are
for tegra graphics related functionality,
i.e. display serial interface, image signal
processor, or media processing stuff.

Only grouper and tilapia presently need this
policy.

Change-Id: I2a7000f69abf3185724d88d428e8237e0ca436ec

Also make su and shell permissive in non-user builds to allow
use of setenforce without violating the neverallow rule.

Change-Id: Ie76ee04e90d5a76dfaa5f56e9e3eb7e283328a3f
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>

Change-Id: If26baa947ff462f5bb09b75918a4130097de5ef4

Change-Id:  I1bdd80f641db05fef4714654515c1e1fbb259794
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>

Every device has a CPU. This is not device specific.

Allow every domain to read these files/directories.
For unknown reasons, these files are accessed by A LOT
of processes.

Allow ueventd to write to these files. This addresses
the following denials seen on mako:

<5>[    4.935602] type=1400 audit(1383167737.512:4): avc:  denied  { read } for  pid=140 comm="ueventd" name="cpu0" dev="sysfs" ino=3163 scontext=u:r:ueventd:s0 tcontext=u:object_r:sysfs_devices_system_cpu:s0 tclass=dir
<5>[    4.935785] type=1400 audit(1383167737.512:5): avc:  denied  { open } for  pid=140 comm="ueventd" name="cpu0" dev="sysfs" ino=3163 scontext=u:r:ueventd:s0 tcontext=u:object_r:sysfs_devices_system_cpu:s0 tclass=dir
<5>[    4.935937] type=1400 audit(1383167737.512:6): avc:  denied  { search } for  pid=140 comm="ueventd" name="cpu0" dev="sysfs" ino=3163 scontext=u:r:ueventd:s0 tcontext=u:object_r:sysfs_devices_system_cpu:s0 tclass=dir
<5>[    4.936120] type=1400 audit(1383167737.512:7): avc:  denied  { write } for  pid=140 comm="ueventd" name="uevent" dev="sysfs" ino=3164 scontext=u:r:ueventd:s0 tcontext=u:object_r:sysfs_devices_system_cpu:s0 tclass=file
<5>[    4.936303] type=1400 audit(1383167737.512:8): avc:  denied  { open } for  pid=140 comm="ueventd" name="uevent" dev="sysfs" ino=3164 scontext=u:r:ueventd:s0 tcontext=u:object_r:sysfs_devices_system_cpu:s0 tclass=file

Change-Id: I4766dc571762d8fae06aa8c26828c070b80f5936

* Keep ueventd in permissive
* Drop unconfined macro to collect logs
* Restore allow rules to current NSA maintained policy

Change-Id: Ic4ee8e24ccd8887fed151ae1e4f197512849f57b

/dev/hw_random is accessed only by init and by EntropyMixer (which
runs inside system_server). Other domains are denied access because
apps/services should be obtaining randomness from the Linux RNG.

Change-Id: Ifde851004301ffd41b2189151a64a0c5989c630f

Some file types used as domain entrypoints were missing the
exec_type attribute.  Add it and add a neverallow rule to
keep it that way.

Change-Id: I7563f3e03940a27ae40ed4d6bb74181c26148849
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>

This is a follow-up CL to the extraction of "system_app" domain
from the "system" domain which left the "system" domain encompassing
just the system_server.

Since this change cannot be made atomically across different
repositories, it temporarily adds a typealias "server" pointing to
"system_server". Once all other repositories have been switched to
"system_server", this alias will be removed.

Change-Id: I90a6850603dcf60049963462c5572d36de62bc00

Remove sys_nice capability from domains; this does not appear to be necessary
and should not be possible in particular for app domains.  If we encounter
specific instances where it should be granted, we can add it back on a
per-domain basis.  Allow it explicitly for the system_server.  Unconfined
domains get it via unconfined_domain() and the rules in unconfined.te.

Change-Id: I9669db80a04a90a22241b2fbc5236a28dcde8c6e
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>

3.4 goldfish kernel supports sysfs labeling so we no longer need this.

Change-Id: I77514a8f3102ac8be957c57d95e7de7d5901f69d
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>

Apps attempting to write to /dev/random or /dev/urandom currently
succeed, but a policy violation is logged. These two Linux RNG
devices are meant to be written to by arbitrary apps. Thus, there's
no reason to deny this capability.

Bug: 10679705

Change-Id: Ife401f1dd2182889471eef7e90fcc92e96f9c4d6

Bug: 10498304
Change-Id: I312665a2cd09fa16ae3f3978aebdb0da99cf1f74

Bug: 9859477
Change-Id: Iadd26cac2f318b81701310788bed795dadfa5b6b

For some reason, the debuggerd socket isn't getting properly
labeled. Work around this bug for now by allowing all domains
to connect to all unix stream sockets.

Bug: 9858255
Change-Id: If994e51b0201ea8cae46341efc76dc71a4e577c8

This is my first attempt at creating an enforcing SELinux domain for
apps, untrusted_apps, and isolated_apps. Much of these rules are based on the
contents of app.te as of commit 11153ef3
with extensive modifications, some of which are included below.

* Allow communication with netd/dnsproxyd, to allow netd to handle
  dns requests
* Allow binder communications with the DNS server
* Allow binder communications with surfaceflinger
* Allow an app to bind to tcp/udp ports
* Allow all domains to read files from the root partition, assuming
  the DAC allows access.

In addition, I added a bunch of "neverallow" rules, to assert that
certain capabilities are never added.

This change has a high probability of breaking someone, somewhere.
If it does, then I'm happy to fix the breakage, rollback this change,
or put untrusted_app into permissive mode.

Change-Id: I83f220135d20ab4f70fbd7be9401b5b1def1fe35

Remove "self:process ptrace" from all SELinux enforced domains.
In general, a process should never need to ptrace itself.
We can add this back to more narrowly scoped domains as needed.

Add a bunch of neverallow assertions to netd.te, to verify that netd
never gets unexpected capabilities.

Change-Id: Ie862dc95bec84068536bb64705667e36210c5f4e

Bug: 9781325
Change-Id: Ib6f6875f690420b59fceb0a32590a2b9ed8dda95

For unlabeled files, revert to DAC rules. This is for backwards
compatibility, as files created before SELinux was in place may
not be properly labeled.

Over time, the number of unlabeled files will decrease, and we can
(hopefully) remove this rule in the future.

To prevent inadvertantly introducing the "relabelto" permission, add
a neverallow domain, and add apps which have a legitimate need to
relabel to this domain.

Bug: 9777552
Change-Id: I71b0ff8abd4925432062007c45b5be85f6f70a88

This change does several things:

1) Restore domain.te to the version present at
cd516a32 . This is the version
currently being distributed in AOSP.

2) Add "allow domain properties_device:file r_file_perms;" to
domain.te, to allow all domains to read /dev/__properties__ .
This change was missing from AOSP.

3) Restore netd.te to the version present at
80c9ba52 . This is the version
currently being distributed in AOSP.

4) Remove anything involving module loading from netd.te. CTS
enforces that Android kernels can't have module loading enabled.

5) Add several new capabilities, plus data file rules, to
netd.te, since netd needs to write to files owned by wifi.

6) Add a new unconfined domain called dnsmasq.te, and allow
transitions from netd to that domain. Over time, we'll tighten up
the dnsmasq.te domain.

7) Add a new unconfined domain called hostapd.te, and allow
transitions from netd to that domain. Over time, we'll tighten up
the hostapd.te domain.

The net effect of these changes is to re-enable SELinux protections
for netd. The policy is FAR from perfect, and allows a lot of wiggle
room, but we can improve it over time.

Testing: as much as possible, I've exercised networking related
functionality, including turning on and off wifi, entering airplane
mode, and enabling tethering and portable wifi hotspots. It's quite
possible I've missed something, and if we experience problems, I
can roll back this change.

Bug: 9618347
Change-Id: I23ff3eebcef629bc7baabcf6962f25f116c4a3c0

This prevents denials from being generated by the base policy.
Over time, these rules will be incrementally tightened to improve
security.

Change-Id: I4be1c987a5d69ac784a56d42fc2c9063c402de11

- Remove dac_read_search as it is no longer required by run-as.
- Introduce a separate type for /dev/tty so that we can allow use of own tty for
for a run-as shell without allowing access to other /dev/tty[0-9]* nodes.
- Allow sigchld notifications for death of run-as and its descendants by adbd.
- Drop redundant rules for executing shell or system commands from untrusted_app;
now covered by rules in app.te.

Change-Id: Ic3bf7bee9eeabf9ad4a20f61fbb142a64bb37c6c