Commit graph

8 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
Nick Kralevich
095fbea563 Strengthen ptrace neverallow rules
Add additional compile time constraints on the ability to ptrace various
sensitive domains.

llkd: remove some domains which llkd should never ptrace, even on
debuggable builds, such as kernel threads and init.

crash_dump neverallows: Remove the ptrace neverallow checks because
it duplicates other neverallow assertions spread throughout the policy.

Test: policy compiles and device boots
Change-Id: Ia4240d1ce7143b983bb048e046bb4729d0af5a6e
2018-09-14 18:32:20 +00:00
Benjamin Gordon
7ed266c678 sepolicy: Fix references to self:capability
commit 9b2e0cbeea added a new
self:global_capability_class_set macro that covers both self:capability
and self:cap_userns.  Apply the new macro to various self:capability
references that have cropped up since then.

Bug: 112307595
Test: policy diff shows new rules are all cap_userns
Change-Id: I3eb38ef07532a8e693fd549dfdbc4a6df5329609
2018-08-21 15:55:23 +00:00
Joel Galenson
d65f26f1b0 Hide bpfloader sys_admin denials.
Bug: 79524845
Test: Boot device and see no denials.
Change-Id: I9316bfd0e3718818a7613a421aedff7da8c87108
2018-05-23 08:36:40 -07:00
Chenbo Feng
be9b15c512 Allow netutils_wrapper to use pinned bpf program
The netutils_wrapper is a process used by vendor code to update the
iptable rules on devices. When it update the rules for a specific chain.
The iptable module will reload the whole chain with the new rule. So
even the netutils_wrapper do not need to add any rules related to xt_bpf
module, it will still reloading the existing iptables rules about xt_bpf
module and need pass through the selinux check again when the rules are
reloading. So we have to grant it the permission to reuse the pinned
program in fs_bpf when it modifies the corresponding iptables chain so
the vendor module will not crash anymore.

Test: device boot and no more denials from netutils_wrapper
Bug: 72111305
Change-Id: I62bdfd922c8194c61b13e2855839aee3f1e349be
(cherry picked from aosp commit 2623ebcf8e)
2018-03-30 13:54:31 -07:00
Chenbo Feng
68ef8c070e Allow netd to setup xt_bpf iptable rules
To better record the network traffic stats for each network interface.
We use xt_bpf netfilter module to do the iface stats accounting instead
of the cgroup bpf filter we currently use for per uid stats accounting.
The xt_bpf module will take pinned eBPF program as iptables rule and run
the program when packet pass through the netfilter hook. To setup the
iptables rules. netd need to be able to access bpf filesystem and run the
bpf program at boot time. The program used will still be created and
pinned by the bpfloader process.

Test: With selinux enforced, run "iptables -L -t raw" should show the
xt_bpf related rule present in bw_raw_PREROUTING chain.
Bug: 72111305

Change-Id: I11efe158d6bd5499df6adf15e8123a76cd67de04
(cherry picked from aosp commit 5c95c16841)
2018-03-21 14:37:37 -07:00
Chenbo Feng
6cd70c2f00 Fix sepolicy for bpf object
With the new patches backported to 4.9 kernels, the bpf file system now
take the same file open flag as bpf_obj_get. So system server now need
read permission only for both bpf map and fs_bpf since we do not need
system server to edit the map. Also, the netd will always pass stdin
stdout fd to the process forked by it and do allow it will cause the
fork and execev fail. We just allow it pass the fd to bpfloader for now
until we have a better option.

Test: bpfloader start successful on devices with 4.9 kernel.
      run cts -m CtsNetTestCases -t android.net.cts.TrafficStatsTest
Bug: 74096311
Bug: 30950746

Change-Id: I747a51cb05ae495c155e7625a3021fc77f921e0d
2018-03-07 14:51:18 +09:00
Chenbo Feng
566411edf2 Add sepolicy to lock down bpf access
Add a new set of sepolicy for the process that only netd use to load
and run ebpf programs. It is the only process that can load eBPF
programs into the kernel and is only used to do that. Add some
neverallow rules regarding which processes have access to bpf objects.

Test: program successfully loaded and pinned at sys/fs/bpf after device
boot. No selinux violation for bpfloader
Bug: 30950746

Change-Id: Ia6bb1afda29ae0749bdc368e2dfc5faa12e81b2f
2018-01-17 23:19:30 +00:00