platform_system_sepolicy/global_macros
Nick Kralevich 85ce2c706e Don't grant hard link capabilities by default.
Modify create_file_perms and create_dir_perms so it doesn't have
the "link" permission. This permission controls whether hard links
are allowed or not on the given file label. Hard links are a common
source of security bugs, and isn't something we want to support by
default.

Get rid of link_file_perms and move the necessary permissions into
create_file_perms and create_dir_perms. Nobody is using this macro,
so it's pointless to keep it around.

Get rid of unlink on directories. It returns EISDIR if you attempt to
do it, independent of SELinux permissions.

SELinux domains which have a need for hard linking for a particular
file type can add it back to their permission set on an as-needed basis.

Add a compile time assertion (neverallow rule) for untrusted_app.
It's particularly dangerous for untrusted_app to ever have hard
link capabilities, and the neverallow rule will prevent regressions.

Bug: 19953790
Change-Id: I5e9493d2bf5da460d074f0bc5ad8ba7c14dec6e0
2015-03-27 08:22:56 -07:00

46 lines
2.5 KiB
Text

#####################################
# Common groupings of object classes.
#
define(`capability_class_set', `{ capability capability2 }')
define(`devfile_class_set', `{ chr_file blk_file }')
define(`notdevfile_class_set', `{ file lnk_file sock_file fifo_file }')
define(`file_class_set', `{ devfile_class_set notdevfile_class_set }')
define(`dir_file_class_set', `{ dir file_class_set }')
define(`socket_class_set', `{ socket tcp_socket udp_socket rawip_socket netlink_socket packet_socket key_socket unix_stream_socket unix_dgram_socket appletalk_socket netlink_route_socket netlink_firewall_socket netlink_tcpdiag_socket netlink_nflog_socket netlink_xfrm_socket netlink_selinux_socket netlink_audit_socket netlink_ip6fw_socket netlink_dnrt_socket netlink_kobject_uevent_socket tun_socket }')
define(`dgram_socket_class_set', `{ udp_socket unix_dgram_socket }')
define(`stream_socket_class_set', `{ tcp_socket unix_stream_socket }')
define(`unpriv_socket_class_set', `{ tcp_socket udp_socket unix_stream_socket unix_dgram_socket }')
define(`ipc_class_set', `{ sem msgq shm ipc }')
#####################################
# Common groupings of permissions.
#
define(`x_file_perms', `{ getattr execute execute_no_trans }')
define(`r_file_perms', `{ getattr open read ioctl lock }')
define(`w_file_perms', `{ open append write }')
define(`rx_file_perms', `{ r_file_perms x_file_perms }')
define(`ra_file_perms', `{ r_file_perms append }')
define(`rw_file_perms', `{ r_file_perms w_file_perms }')
define(`rwx_file_perms', `{ rw_file_perms x_file_perms }')
define(`create_file_perms', `{ create rename setattr unlink rw_file_perms }')
define(`r_dir_perms', `{ open getattr read search ioctl }')
define(`w_dir_perms', `{ open search write add_name remove_name }')
define(`ra_dir_perms', `{ r_dir_perms add_name write }')
define(`rw_dir_perms', `{ r_dir_perms w_dir_perms }')
define(`create_dir_perms', `{ create reparent rename rmdir setattr rw_dir_perms }')
define(`r_ipc_perms', `{ getattr read associate unix_read }')
define(`w_ipc_perms', `{ write unix_write }')
define(`rw_ipc_perms', `{ r_ipc_perms w_ipc_perms }')
define(`create_ipc_perms', `{ create setattr destroy rw_ipc_perms }')
#####################################
# Common socket permission sets.
define(`rw_socket_perms', `{ ioctl read getattr write setattr lock append bind connect getopt setopt shutdown }')
define(`create_socket_perms', `{ create rw_socket_perms }')
define(`rw_stream_socket_perms', `{ rw_socket_perms listen accept }')
define(`create_stream_socket_perms', `{ create rw_stream_socket_perms }')