android_system_sepolicy/public/dhcp.te
Jeff Vander Stoep 7a4af30b38 Start the process of locking down proc/net
Files in /proc/net leak information. This change is the first step in
determining which files apps may use, whitelisting benign access, and
otherwise removing access while providing safe alternative APIs.

To that end, this change:
* Introduces the proc_net_type attribute which will assigned to any
new SELinux types in /proc/net to avoid removing access to privileged
processes. These processes may be evaluated later, but are lower
priority than apps.
* Labels /proc/net/{tcp,tcp6,udp,udp6} as proc_net_vpn due to existing
use by VPN apps. This may be replaced by an alternative API.
* Audits all other proc/net access for apps.
* Audits proc/net access for other processes which are currently
granted broad read access to /proc/net but should not be including
storaged, zygote, clatd, logd, preopt2cachename and vold.

Bug: 9496886
Bug: 68016944
Test: Boot Taimen-userdebug. On both wifi and cellular: stream youtube
    navigate maps, send text message, make voice call, make video call.
    Verify no avc "granted" messages in the logs.
Test: A few VPN apps including "VPN Monster", "Turbo VPN", and
"Freighter". Verify no logspam with the current setup.
Test: atest CtsNativeNetTestCases
Test: atest netd_integration_test
Test: atest QtaguidPermissionTest
Test: atest FileSystemPermissionTest

Change-Id: I7e49f796a25cf68bc698c6c9206e24af3ae11457
Merged-In: I7e49f796a25cf68bc698c6c9206e24af3ae11457
(cherry picked from commit 087318957f)
2018-05-04 21:36:33 +00:00

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1.1 KiB
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type dhcp, domain;
type dhcp_exec, exec_type, file_type;
net_domain(dhcp)
allow dhcp cgroup:dir { create write add_name };
allow dhcp self:global_capability_class_set { setgid setuid net_admin net_raw net_bind_service };
allow dhcp self:packet_socket create_socket_perms_no_ioctl;
allow dhcp self:netlink_route_socket nlmsg_write;
allow dhcp shell_exec:file rx_file_perms;
allow dhcp system_file:file rx_file_perms;
not_full_treble(`allow dhcp vendor_file:file rx_file_perms;')
# dhcpcd runs dhcpcd-hooks/*, which runs getprop / setprop (toolbox_exec)
allow dhcp toolbox_exec:file rx_file_perms;
# For /proc/sys/net/ipv4/conf/*/promote_secondaries
allow dhcp proc_net_type:file write;
set_prop(dhcp, dhcp_prop)
set_prop(dhcp, pan_result_prop)
allow dhcp dhcp_data_file:dir create_dir_perms;
allow dhcp dhcp_data_file:file create_file_perms;
# PAN connections
allow dhcp netd:fd use;
allow dhcp netd:fifo_file rw_file_perms;
allow dhcp netd:{ dgram_socket_class_set unix_stream_socket } { read write };
allow dhcp netd:{ netlink_kobject_uevent_socket netlink_route_socket netlink_nflog_socket } { read write };