public/mediacodec.te

# mediacodec - audio and video codecs live here
type mediacodec, domain;
type mediacodec_exec, exec_type, file_type;

typeattribute mediacodec mlstrustedsubject;

binder_use(mediacodec)
binder_call(mediacodec, binderservicedomain)
binder_call(mediacodec, appdomain)
binder_service(mediacodec)

add_service(mediacodec, mediacodec_service)
allow mediacodec mediametrics_service:service_manager find;
allow mediacodec surfaceflinger_service:service_manager find;
allow mediacodec gpu_device:chr_file rw_file_perms;
allow mediacodec video_device:chr_file rw_file_perms;
allow mediacodec video_device:dir search;
allow mediacodec ion_device:chr_file rw_file_perms;
allow mediacodec hal_graphics_allocator:fd use;
allow mediacodec hal_camera:fd use;

crash_dump_fallback(mediacodec)

# hidl access
hwbinder_use(mediacodec)
hwallocator_use(mediacodec)
allow mediacodec system_file:dir { open read };

# Recieve gralloc buffer FDs from bufferhubd. Note that mediacodec never
# directly connects to bufferhubd via PDX. Instead, a VR app acts as a bridge
# between those two: it talks to mediacodec via Binder and talks to bufferhubd
# via PDX. Thus, there is no need to use use_pdx macro.
allow mediacodec bufferhubd:fd use;

###
### neverallow rules
###

# mediacodec should never execute any executable without a
# domain transition
neverallow mediacodec { file_type fs_type }:file execute_no_trans;

# The goal of the mediaserver split is to place media processing code into
# restrictive sandboxes with limited responsibilities and thus limited
# permissions. Example: Audioserver is only responsible for controlling audio
# hardware and processing audio content. Cameraserver does the same for camera
# hardware/content. Etc.
#
# Media processing code is inherently risky and thus should have limited
# permissions and be isolated from the rest of the system and network.
# Lengthier explanation here:
# https://android-developers.googleblog.com/2016/05/hardening-media-stack.html
neverallow mediacodec domain:{ tcp_socket udp_socket rawip_socket } *;