blob: 08d4e1f94dfc0f9ba8e318d0ee9d63a375b67f9e [file] [log] [blame]
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# MLS policy constraints
#
#
# Process constraints
#
# Process transition: Require equivalence unless the subject is trusted.
mlsconstrain process { transition dyntransition }
((h1 eq h2 and l1 eq l2) or t1 == mlstrustedsubject);
# Process read operations: No read up unless trusted.
mlsconstrain process { getsched getsession getpgid getcap getattr ptrace share }
(l1 dom l2 or t1 == mlstrustedsubject);
# Process write operations: Require equivalence unless trusted.
mlsconstrain process { sigkill sigstop signal setsched setpgid setcap setrlimit ptrace share }
(l1 eq l2 or t1 == mlstrustedsubject);
#
# Socket constraints
#
# Create/relabel operations: Subject must be equivalent to object unless
# the subject is trusted. Sockets inherit the range of their creator.
mlsconstrain socket_class_set { create relabelfrom relabelto }
((h1 eq h2 and l1 eq l2) or t1 == mlstrustedsubject);
# Datagram send: Sender must be equivalent to the receiver unless one of them
# is trusted.
mlsconstrain unix_dgram_socket { sendto }
(l1 eq l2 or t1 == mlstrustedsubject or t2 == mlstrustedsubject);
# Stream connect: Client must be equivalent to server unless one of them
# is trusted.
mlsconstrain unix_stream_socket { connectto }
(l1 eq l2 or t1 == mlstrustedsubject or t2 == mlstrustedsubject);
#
# Directory/file constraints
#
# Create/relabel operations: Subject must be equivalent to object unless
# the subject is trusted. Also, files should always be single-level.
# Do NOT exempt mlstrustedobject types from this constraint.
mlsconstrain dir_file_class_set { create relabelfrom relabelto }
(l2 eq h2 and (l1 eq l2 or t1 == mlstrustedsubject));
#
# Constraints for app data files only.
#
# Only constrain open, not read/write.
# Also constrain other forms of manipulation, e.g. chmod/chown, unlink, rename, etc.
# Subject must dominate object unless the subject is trusted.
mlsconstrain dir { open search getattr setattr rename add_name remove_name reparent rmdir }
( (t2 != app_data_file and t2 != privapp_data_file ) or l1 dom l2 or t1 == mlstrustedsubject);
mlsconstrain { file sock_file } { open setattr unlink link rename }
( (t2 != app_data_file and t2 != privapp_data_file and t2 != appdomain_tmpfs) or l1 dom l2 or t1 == mlstrustedsubject);
# For symlinks in app_data_file, require equivalence in order to manipulate or follow (read).
mlsconstrain { lnk_file } { open setattr unlink link rename read }
( (t2 != app_data_file) or l1 eq l2 or t1 == mlstrustedsubject);
# For priv_app_data_file, continue to use dominance for symlinks because dynamite relies on this.
# TODO: Migrate to equivalence when it's no longer needed.
mlsconstrain { lnk_file } { open setattr unlink link rename read }
( (t2 != privapp_data_file and t2 != appdomain_tmpfs) or l1 dom l2 or t1 == mlstrustedsubject);
#
# Constraints for file types other than app data files.
#
# Read operations: Subject must dominate object unless the subject
# or the object is trusted.
mlsconstrain dir { read getattr search }
(t2 == app_data_file or t2 == privapp_data_file or l1 dom l2 or t1 == mlstrustedsubject or t2 == mlstrustedobject);
mlsconstrain { file lnk_file sock_file chr_file blk_file } { read getattr execute }
(t2 == app_data_file or t2 == privapp_data_file or t2 == appdomain_tmpfs or l1 dom l2 or t1 == mlstrustedsubject or t2 == mlstrustedobject);
# Write operations: Subject must be equivalent to the object unless the
# subject or the object is trusted.
mlsconstrain dir { write setattr rename add_name remove_name reparent rmdir }
(t2 == app_data_file or t2 == privapp_data_file or l1 eq l2 or t1 == mlstrustedsubject or t2 == mlstrustedobject);
mlsconstrain { file lnk_file sock_file chr_file blk_file } { write setattr append unlink link rename }
(t2 == app_data_file or t2 == privapp_data_file or t2 == appdomain_tmpfs or l1 eq l2 or t1 == mlstrustedsubject or t2 == mlstrustedobject);
# Special case for FIFOs.
# These can be unnamed pipes, in which case they will be labeled with the
# creating process' label. Thus we also have an exemption when the "object"
# is a domain type, so that processes can communicate via unnamed pipes
# passed by binder or local socket IPC.
mlsconstrain fifo_file { read getattr }
(l1 dom l2 or t1 == mlstrustedsubject or t2 == mlstrustedobject or t2 == domain);
mlsconstrain fifo_file { write setattr append unlink link rename }
(l1 eq l2 or t1 == mlstrustedsubject or t2 == mlstrustedobject or t2 == domain);
#
# Binder IPC constraints
#
# Presently commented out, as apps are expected to call one another.
# This would only make sense if apps were assigned categories
# based on allowable communications rather than per-app categories.
#mlsconstrain binder call
# (l1 eq l2 or t1 == mlstrustedsubject or t2 == mlstrustedsubject);