b13921c3f0
Goal is to gain a better handle on who has access to which maps
and to allow (with bpfloader changes to create in one directory
and move into the target directory) per-map selection of
selinux context, while still having reasonable defaults for stuff
pinned directly into the target location.
BPFFS (ie. /sys/fs/bpf) labelling is as follows:
subdirectory selinux context mainline usecase / usable by
/ fs_bpf no (*) core operating system (ie. platform)
/net_private fs_bpf_net_private yes, T+ network_stack
/net_shared fs_bpf_net_shared yes, T+ network_stack & system_server
/netd_readonly fs_bpf_netd_readonly yes, T+ network_stack & system_server & r/o to netd
/netd_shared fs_bpf_netd_shared yes, T+ network_stack & system_server & netd [**]
/tethering fs_bpf_tethering yes, S+ network_stack
/vendor fs_bpf_vendor no, T+ vendor
* initial support for bpf was added back in P,
but things worked differently back then with no bpfloader,
and instead netd doing stuff by hand,
bpfloader with pinning into /sys/fs/bpf was (I believe) added in Q
(and was definitely there in R)
** additionally bpf programs are accesible to netutils_wrapper
for use by iptables xt_bpf extensions
'mainline yes' currently means shipped by the com.android.tethering apex,
but this is really another case of bad naming, as it's really
the 'networking/connectivity/tethering' apex / mainline module.
Long term the plan is to merge a few other networking mainline modules
into it (and maybe give it a saner name...).
The reason for splitting net_private vs tethering is that:
S+ must support 4.9+ kernels and S era bpfloader v0.2+
T+ must support 4.14+ kernels and T beta3 era bpfloader v0.13+
The kernel affects the intelligence of the in-kernel bpf verifier
and the available bpf helper functions. Older kernels have
a tendency to reject programs that newer kernels allow.
/ && /vendor are not shipped via mainline, so only need to work
with the bpfloader that's part of the core os.
Bug: 218408035
Test: TreeHugger, manually on cuttlefish
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I674866ebe32aca4fc851818c1ffcbec12ac4f7d4
(cherry picked from commit 15715aea32
)
188 lines
6.3 KiB
Text
188 lines
6.3 KiB
Text
# network manager
|
|
type netd, domain, mlstrustedsubject;
|
|
type netd_exec, system_file_type, exec_type, file_type;
|
|
|
|
net_domain(netd)
|
|
# in addition to ioctls allowlisted for all domains, grant netd priv_sock_ioctls.
|
|
allowxperm netd self:udp_socket ioctl priv_sock_ioctls;
|
|
|
|
r_dir_file(netd, cgroup)
|
|
|
|
allow netd system_server:fd use;
|
|
|
|
allow netd self:global_capability_class_set { net_admin net_raw kill };
|
|
# Note: fsetid is deliberately not included above. fsetid checks are
|
|
# triggered by chmod on a directory or file owned by a group other
|
|
# than one of the groups assigned to the current process to see if
|
|
# the setgid bit should be cleared, regardless of whether the setgid
|
|
# bit was even set. We do not appear to truly need this capability
|
|
# for netd to operate.
|
|
dontaudit netd self:global_capability_class_set fsetid;
|
|
|
|
# Allow netd to open /dev/tun, set it up and pass it to clatd
|
|
allow netd tun_device:chr_file rw_file_perms;
|
|
allowxperm netd tun_device:chr_file ioctl { TUNGETIFF TUNSETIFF };
|
|
allow netd self:tun_socket create;
|
|
|
|
allow netd self:netlink_kobject_uevent_socket create_socket_perms_no_ioctl;
|
|
allow netd self:netlink_route_socket nlmsg_write;
|
|
allow netd self:netlink_nflog_socket create_socket_perms_no_ioctl;
|
|
allow netd self:netlink_socket create_socket_perms_no_ioctl;
|
|
allow netd self:netlink_tcpdiag_socket { create_socket_perms_no_ioctl nlmsg_read nlmsg_write };
|
|
allow netd self:netlink_generic_socket create_socket_perms_no_ioctl;
|
|
allow netd self:netlink_netfilter_socket create_socket_perms_no_ioctl;
|
|
allow netd shell_exec:file rx_file_perms;
|
|
allow netd system_file:file x_file_perms;
|
|
not_full_treble(`allow netd vendor_file:file x_file_perms;')
|
|
allow netd devpts:chr_file rw_file_perms;
|
|
|
|
# Acquire advisory lock on /system/etc/xtables.lock. If this file doesn't
|
|
# exist, suppress the denial.
|
|
allow netd system_file:file lock;
|
|
dontaudit netd system_file:dir write;
|
|
|
|
# Allow netd to write to qtaguid ctrl file.
|
|
# TODO: Add proper rules to prevent other process to access qtaguid_proc file
|
|
# after migration complete
|
|
allow netd proc_qtaguid_ctrl:file rw_file_perms;
|
|
# Allow netd to read /dev/qtaguid. This is the same privilege level that normal apps have.
|
|
allow netd qtaguid_device:chr_file r_file_perms;
|
|
|
|
r_dir_file(netd, proc_net_type)
|
|
# For /proc/sys/net/ipv[46]/route/flush.
|
|
allow netd proc_net_type:file rw_file_perms;
|
|
|
|
# Enables PppController and interface enumeration (among others)
|
|
allow netd sysfs:dir r_dir_perms;
|
|
r_dir_file(netd, sysfs_net)
|
|
|
|
# Allows setting interface MTU
|
|
allow netd sysfs_net:file w_file_perms;
|
|
|
|
# TODO: added to match above sysfs rule. Remove me?
|
|
allow netd sysfs_usb:file write;
|
|
|
|
r_dir_file(netd, cgroup_v2)
|
|
|
|
# TODO: netd previously thought it needed these permissions to do WiFi related
|
|
# work. However, after all the WiFi stuff is gone, we still need them.
|
|
# Why?
|
|
allow netd self:global_capability_class_set { dac_override dac_read_search chown };
|
|
|
|
# Needed to update /data/misc/net/rt_tables
|
|
allow netd net_data_file:file create_file_perms;
|
|
allow netd net_data_file:dir rw_dir_perms;
|
|
allow netd self:global_capability_class_set fowner;
|
|
|
|
# Needed to lock the iptables lock.
|
|
allow netd system_file:file lock;
|
|
|
|
# Allow netd to spawn dnsmasq in it's own domain
|
|
allow netd dnsmasq:process signal;
|
|
|
|
# Allow netd to publish a binder service and make binder calls.
|
|
binder_use(netd)
|
|
add_service(netd, netd_service)
|
|
add_service(netd, dnsresolver_service)
|
|
add_service(netd, mdns_service)
|
|
allow netd dumpstate:fifo_file { getattr write };
|
|
|
|
# Allow netd to call into the system server so it can check permissions.
|
|
allow netd system_server:binder call;
|
|
allow netd permission_service:service_manager find;
|
|
|
|
# Allow netd to talk to the framework service which collects netd events.
|
|
allow netd netd_listener_service:service_manager find;
|
|
|
|
# Allow netd to operate on sockets that are passed to it.
|
|
allow netd netdomain:{
|
|
icmp_socket
|
|
tcp_socket
|
|
udp_socket
|
|
rawip_socket
|
|
tun_socket
|
|
} { read write getattr setattr getopt setopt };
|
|
allow netd netdomain:fd use;
|
|
|
|
# give netd permission to read and write netlink xfrm
|
|
allow netd self:netlink_xfrm_socket { create_socket_perms_no_ioctl nlmsg_write nlmsg_read };
|
|
|
|
# Allow netd to register as hal server.
|
|
add_hwservice(netd, system_net_netd_hwservice)
|
|
hwbinder_use(netd)
|
|
|
|
# AIDL hal server
|
|
binder_call(system_net_netd_service, servicemanager)
|
|
add_service(netd, system_net_netd_service)
|
|
|
|
###
|
|
### Neverallow rules
|
|
###
|
|
### netd should NEVER do any of this
|
|
|
|
# Block device access.
|
|
neverallow netd dev_type:blk_file { read write };
|
|
|
|
# ptrace any other app
|
|
neverallow netd { domain }:process ptrace;
|
|
|
|
# Write to /system.
|
|
neverallow netd system_file:dir_file_class_set write;
|
|
|
|
# Write to files in /data/data or system files on /data
|
|
neverallow netd { app_data_file_type system_data_file }:dir_file_class_set write;
|
|
|
|
# only system_server, dumpstate and network stack app may find netd service
|
|
neverallow {
|
|
domain
|
|
-system_server
|
|
-dumpstate
|
|
-network_stack
|
|
-netd
|
|
-netutils_wrapper
|
|
} netd_service:service_manager find;
|
|
|
|
# only system_server, dumpstate and network stack app may find dnsresolver service
|
|
neverallow {
|
|
domain
|
|
-system_server
|
|
-dumpstate
|
|
-network_stack
|
|
-netd
|
|
-netutils_wrapper
|
|
} dnsresolver_service:service_manager find;
|
|
|
|
# only system_server, dumpstate and network stack app may find mdns service
|
|
neverallow {
|
|
domain
|
|
-system_server
|
|
-dumpstate
|
|
-network_stack
|
|
-netd
|
|
-netutils_wrapper
|
|
} mdns_service:service_manager find;
|
|
|
|
# apps may not interact with netd over binder.
|
|
neverallow { appdomain -network_stack } netd:binder call;
|
|
neverallow netd { appdomain -network_stack userdebug_or_eng(`-su') }:binder call;
|
|
|
|
# If an already existing file is opened with O_CREATE, the kernel might generate
|
|
# a false report of a create denial. Silence these denials and make sure that
|
|
# inappropriate permissions are not granted.
|
|
neverallow netd proc_net:dir no_w_dir_perms;
|
|
dontaudit netd proc_net:dir write;
|
|
|
|
neverallow netd sysfs_net:dir no_w_dir_perms;
|
|
dontaudit netd sysfs_net:dir write;
|
|
|
|
# Netd should not have SYS_ADMIN privs.
|
|
neverallow netd self:capability sys_admin;
|
|
dontaudit netd self:capability sys_admin;
|
|
|
|
# Netd should not have SYS_MODULE privs, nor should it be requesting module loads
|
|
# (things it requires should be built directly into the kernel)
|
|
dontaudit netd self:capability sys_module;
|
|
|
|
dontaudit netd kernel:system module_request;
|
|
|
|
dontaudit netd appdomain:unix_stream_socket { read write };
|