In order to track time in state data using eBPF, system_server needs
to be able to attach BPF programs to tracepoints, which involves:
- calling perf_event_open and the PERF_EVENT_IOC_SET_BPF ioctl
- running BPF programs
- reading tracepoint ids from tracefs
Grant system_server the necessary permissions for these tasks
Test: modify system_server to try to attach programs; check for
denials
Bug: 138317993
Change-Id: I07dafd325a9c57d53767a09d4ca7b0fb2dd2d328
Signed-off-by: Connor O'Brien <connoro@google.com>
bpf programs/maps are now loaded by the bpfloader, not netd
Test: built/installed on crosshatch which uses eBPF - no avc denials
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I1ebd82e6730d62d1966da3c4634ecd78ce703543
init needs to execute bpfloader as a one-shot service. Add sepolicy for
the same. Also update old rules allowing init to fork/exec bpfloader and
remove rules allowing netd to do so.
Bug: 112334572
Change-Id: Ic242cd507731ed8af3f8e94d4fccc95819831d37
Signed-off-by: Joel Fernandes <joelaf@google.com>
bpfloader needs to load bpf programs with tracepoints in them. The
tracepoint programs are not activated but are just loaded and pinned.
The kernel expects the process doing this to have CAP_SYS_ADMIN. Since
bpfloader was intended to be a 1-shot run and exit process with security
privileges, lets assign it CAP_SYS_ADMIN so that it is able to load the
tracepoint programs.
Bug: 112334572
Change-Id: Icf9b5d95615e69f5c28dc28f021b07f49710c97d
Signed-off-by: Joel Fernandes <joelaf@google.com>
Recent change in netd and bpfloader switched the creater of bpf maps
from netd to bpfloader. Change the rules related to it to make sure it
doesn't fail.
Test: dumpsys netd trafficcontroller
Bug: 112334572
Change-Id: I016ff68b58ef7b12bdfdebc2fd178be1d0206a62
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
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
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
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)
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)
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
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
