we will initialize the label to biba/low for files that have been created
through an NFS RPC. This is a safe default given the default nature of our
NFS implementation, there is not a whole lot of data integrity there by
default. This also fixes kernel panics associated with file creation over NFS
while creating files on filesystems which have multilabel enabled with BIBA
enabled.
MFC after: 2 weeks
Discussed with: rwatson
security.mac.biba.interfaces_equal
If non-zero, all network interfaces be created with the label:
biba/equal(equal-equal)
This is useful where programs which initialize network interfaces
do not have any labeling support. This includes dhclient and ppp. A
long term solution is to add labeling support into dhclient(8)
and ppp(8), and remove this variable.
It should be noted that this behavior is different then setting the:
security.mac.biba.trust_all_interfaces
sysctl variable, as this will create interfaces with a biba/high label.
Lower integrity processes are not able to write to the interface in this
event. The security.mac.biba.interfaces_equal will override
trust_all_interfaces.
The security.mac.biba.interfaces_equal variable will be set to zero
or disabled by default.
MFC after: 2 weeks
provided access to the root file system before the start of the
init process. This was used briefly by SEBSD before it knew about
preloading data in the loader, and using that method to gain
access to data earlier results in fewer inconsistencies in the
approach. Policy modules still have access to the root file system
creation event through the mac_create_mount() entry point.
Removed now, and will be removed from RELENG_6, in order to gain
third party policy dependencies on the entry point for the lifetime
of the 6.x branch.
MFC after: 3 days
Submitted by: Chris Vance <Christopher dot Vance at SPARTA dot com>
Sponsored by: SPARTA
process that caused the clone event to take place for the device driver
creating the device. This allows cloned device drivers to adapt the
device node based on security aspects of the process, such as the uid,
gid, and MAC label.
- Add a cred reference to struct cdev, so that when a device node is
instantiated as a vnode, the cloning credential can be exposed to
MAC.
- Add make_dev_cred(), a version of make_dev() that additionally
accepts the credential to stick in the struct cdev. Implement it and
make_dev() in terms of a back-end make_dev_credv().
- Add a new event handler, dev_clone_cred, which can be registered to
receive the credential instead of dev_clone, if desired.
- Modify the MAC entry point mac_create_devfs_device() to accept an
optional credential pointer (may be NULL), so that MAC policies can
inspect and act on the label or other elements of the credential
when initializing the skeleton device protections.
- Modify tty_pty.c to register clone_dev_cred and invoke make_dev_cred(),
so that the pty clone credential is exposed to the MAC Framework.
While currently primarily focussed on MAC policies, this change is also
a prerequisite for changes to allow ptys to be instantiated with the UID
of the process looking up the pty. This requires further changes to the
pty driver -- in particular, to immediately recycle pty nodes on last
close so that the credential-related state can be recreated on next
lookup.
Submitted by: Andrew Reisse <andrew.reisse@sparta.com>
Obtained from: TrustedBSD Project
Sponsored by: SPAWAR, SPARTA
MFC after: 1 week
MFC note: Merge to 6.x, but not 5.x for ABI reasons
redundant with respect to existing mbuf copy label routines. Expose
a new mac_copy_mbuf() routine at the top end of the Framework and
use that; use the existing mpo_copy_mbuf_label() routine on the
bottom end.
Obtained from: TrustedBSD Project
Sponsored by: SPARTA, SPAWAR
Approved by: re (scottl)
points to convert _sema() to _sem() for consistency purposes with
respect to the other semaphore-related entry points:
mac_init_sysv_sema() -> mac_init_sysv_sem()
mac_destroy_sysv_sem() -> mac_destroy_sysv_sem()
mac_create_sysv_sema() -> mac_create_sysv_sem()
mac_cleanup_sysv_sema() -> mac_cleanup_sysv_sem()
Congruent changes are made to the policy interface to support this.
Obtained from: TrustedBSD Project
Sponsored by: SPAWAR, SPARTA
access to POSIX Semaphores:
mac_init_posix_sem() Initialize label for POSIX semaphore
mac_create_posix_sem() Create POSIX semaphore
mac_destroy_posix_sem() Destroy POSIX semaphore
mac_check_posix_sem_destroy() Check whether semaphore may be destroyed
mac_check_posix_sem_getvalue() Check whether semaphore may be queried
mac_check_possix_sem_open() Check whether semaphore may be opened
mac_check_posix_sem_post() Check whether semaphore may be posted to
mac_check_posix_sem_unlink() Check whether semaphore may be unlinked
mac_check_posix_sem_wait() Check whether may wait on semaphore
Update Biba, MLS, Stub, and Test policies to implement these entry points.
For information flow policies, most semaphore operations are effectively
read/write.
Submitted by: Dandekar Hrishikesh <rishi_dandekar at sbcglobal dot net>
Sponsored by: DARPA, McAfee, SPARTA
Obtained from: TrustedBSD Project
MAP_SHARED so that the entry point gets executed un-conditionally.
This may be useful for security policies which want to perform access
control checks around run-time linking.
-add the mmap(2) flags argument to the check_vnode_mmap entry point
so that we can make access control decisions based on the type of
mapped object.
-update any dependent API around this parameter addition such as
function prototype modifications, entry point parameter additions
and the inclusion of sys/mman.h header file.
-Change the MLS, BIBA and LOMAC security policies so that subject
domination routines are not executed unless the type of mapping is
shared. This is done to maintain compatibility between the old
vm_mmap_vnode(9) and these policies.
Reviewed by: rwatson
MFC after: 1 month
accurately represents the intention of the 'single' label element in
Biba and MLS labels. It also approximates the use of 'effective' in
traditional UNIX credentials, and avoids confusion with 'singlelabel'
in the context of file systems.
Inspired by: trhodes
network interfaces. This global mutex will protect all ifnet labels.
Acquire the mutex across various MAC activities on interfaces, such
as security checks, propagating interface labels to mbufs generated
from the interface, retrieving and setting the interface label.
Introduce mpo_copy_ifnet_label MAC policy entry point to copy the
value of an interface label from one label to another. Use this
to avoid performing a label externalize while holding mac_ifnet_mtx;
copy the label to a temporary ifnet label and then externalize that.
Implement mpo_copy_ifnet_label for various MAC policies that
implement interface labeling using generic label copying routines.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, McAfee Research
Now I believe it is done in the right way.
Removed some XXMAC cases, we now assume 'high' integrity level for all
sysctls, except those with CTLFLAG_ANYBODY flag set. No more magic.
Reviewed by: rwatson
Approved by: rwatson, scottl (mentor)
Tested with: LINT (compilation), mac_biba(4) (functionality)
to use the "year1-year3" format, as opposed to "year1, year2, year3".
This seems to make lawyers more happy, but also prevents the
lines from getting excessively long as the years start to add up.
Suggested by: imp
would allocate two 'struct pipe's from the pipe zone, and malloc a
mutex.
- Create a new "struct pipepair" object holding the two 'struct
pipe' instances, struct mutex, and struct label reference. Pipe
structures now have a back-pointer to the pipe pair, and a
'pipe_present' flag to indicate whether the half has been
closed.
- Perform mutex init/destroy in zone init/destroy, avoiding
reallocating the mutex for each pipe. Perform most pipe structure
setup in zone constructor.
- VM memory mappings for pageable buffers are still done outside of
the UMA zone.
- Change MAC API to speak 'struct pipepair' instead of 'struct pipe',
update many policies. MAC labels are also handled outside of the
UMA zone for now. Label-only policy modules don't have to be
recompiled, but if a module is recompiled, its pipe entry points
will need to be updated. If a module actually reached into the
pipe structures (unlikely), that would also need to be modified.
These changes substantially simplify failure handling in the pipe
code as there are many fewer possible failure modes.
On half-close, pipes no longer free the 'struct pipe' for the closed
half until a full-close takes place. However, VM mapped buffers
are still released on half-close.
Some code refactoring is now possible to clean up some of the back
references, etc; this patch attempts not to change the structure
of most of the pipe implementation, only allocation/free code
paths, so as to avoid introducing bugs (hopefully).
This cuts about 8%-9% off the cost of sequential pipe allocation
and free in system call tests on UP and SMP in my micro-benchmarks.
May or may not make a difference in macro-benchmarks, but doing
less work is good.
Reviewed by: juli, tjr
Testing help: dwhite, fenestro, scottl, et al
wait, rather than the socket label. This avoids reaching up to
the socket layer during connection close, which requires locking
changes. To do this, introduce MAC Framework entry point
mac_create_mbuf_from_inpcb(), which is called from tcp_twrespond()
instead of calling mac_create_mbuf_from_socket() or
mac_create_mbuf_netlayer(). Introduce MAC Policy entry point
mpo_create_mbuf_from_inpcb(), and implementations for various
policies, which generally just copy label data from the inpcb to
the mbuf. Assert the inpcb lock in the entry point since we
require consistency for the inpcb label reference.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
and the mpo_create_cred() MAC policy entry point to
mpo_copy_cred_label(). This is more consistent with similar entry
points for creation and label copying, as mac_create_cred() was
called from crdup() as opposed to during process creation. For
a number of policies, this removes the requirement for special
handling when copying credential labels, and improves consistency.
Approved by: re (scottl)
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
the MAC label referenced from 'struct socket' in the IPv4 and
IPv6-based protocols. This permits MAC labels to be checked during
network delivery operations without dereferencing inp->inp_socket
to get to so->so_label, which will eventually avoid our having to
grab the socket lock during delivery at the network layer.
This change introduces 'struct inpcb' as a labeled object to the
MAC Framework, along with the normal circus of entry points:
initialization, creation from socket, destruction, as well as a
delivery access control check.
For most policies, the inpcb label will simply be a cache of the
socket label, so a new protocol switch method is introduced,
pr_sosetlabel() to notify protocols that the socket layer label
has been updated so that the cache can be updated while holding
appropriate locks. Most protocols implement this using
pru_sosetlabel_null(), but IPv4/IPv6 protocols using inpcbs use
the the worker function in_pcbsosetlabel(), which calls into the
MAC Framework to perform a cache update.
Biba, LOMAC, and MLS implement these entry points, as do the stub
policy, and test policy.
Reviewed by: sam, bms
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
system calls, and prefer these calls over getsockopt()/setsockopt()
for ABI reasons. When addressing UNIX domain sockets, these calls
retrieve and modify the socket label, not the label of the
rendezvous vnode.
- Create mac_copy_socket_label() entry point based on
mac_copy_pipe_label() entry point, intended to copy the socket
label into temporary storage that doesn't require a socket lock
to be held (currently Giant).
- Implement mac_copy_socket_label() for various policies.
- Expose socket label allocation, free, internalize, externalize
entry points as non-static from mac_net.c.
- Use mac_socket_label_set() in __mac_set_fd().
MAC-aware applications may now use mac_get_fd(), mac_set_fd(), and
mac_get_peer() to retrieve and set various socket labels without
directly invoking the getsockopt() interface.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
extra argument to the devfs MAC policy entry points was accidentally
merged from the MAC branch during my earlier commit to these policies,
and is not scheduled to be merged just yet.
in various kernel objects to represent security data, we embed a
(struct label *) pointer, which now references labels allocated using
a UMA zone (mac_label.c). This allows the size and shape of struct
label to be varied without changing the size and shape of these kernel
objects, which become part of the frozen ABI with 5-STABLE. This opens
the door for boot-time selection of the number of label slots, and hence
changes to the bound on the number of simultaneous labeled policies
at boot-time instead of compile-time. This also makes it easier to
embed label references in new objects as required for locking/caching
with fine-grained network stack locking, such as inpcb structures.
This change also moves us further in the direction of hiding the
structure of kernel objects from MAC policy modules, not to mention
dramatically reducing the number of '&' symbols appearing in both the
MAC Framework and MAC policy modules, and improving readability.
While this results in minimal performance change with MAC enabled, it
will observably shrink the size of a number of critical kernel data
structures for the !MAC case, and should have a small (but measurable)
performance benefit (i.e., struct vnode, struct socket) do to memory
conservation and reduced cost of zeroing memory.
NOTE: Users of MAC must recompile their kernel and all MAC modules as a
result of this change. Because this is an API change, third party
MAC modules will also need to be updated to make less use of the '&'
symbol.
Suggestions from: bmilekic
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
if_xname, if_dname, and if_dunit. if_xname is the name of the interface
and if_dname/unit are the driver name and instance.
This change paves the way for interface renaming and enhanced pseudo
device creation and configuration symantics.
Approved By: re (in principle)
Reviewed By: njl, imp
Tested On: i386, amd64, sparc64
Obtained From: NetBSD (if_xname)
already checks suser on a network interface relabel, so don't dup it
here. Rely solely on the Biba definition of privilege, which is
already tested.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
Submitted by: Andrew Reisse <areisse@nailabs.com>
the MAC policy modules to improve robustness against C string
bugs and vulnerabilities. Following these revisions, all
string construction of labels for export to userspace (or
elsewhere) is performed using the sbuf API, which prevents
the consumer from having to perform laborious and intricate
pointer and buffer checks. This substantially simplifies
the externalization logic, both at the MAC Framework level,
and in individual policies; this becomes especially useful
when policies export more complex label data, such as with
compartments in Biba and MLS.
Bundled in here are some other minor fixes associated with
externalization: including avoiding malloc while holding the
process mutex in mac_lomac, and hence avoid a failure mode
when printing labels during a downgrade operation due to
the removal of the M_NOWAIT case.
This has been running in the MAC development tree for about
three weeks without problems.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
mpo_copy_mbuf_label() entry point for Biba and MLS, respectively.
Otherwise, labels in m_tags may not be properly propagated across
some classes of mbuf operations. This problem caused these policies
to fail-stop the system with a panic.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
of C strings internally; C strings require a lot of return value
checking that (a) takes a lot of space, and (b) is difficult to get
right. Prior to the advent of compartment support, modeling APIs
for helper functions on snprintf worked fine; with the additional
complexity, the sbuf_printf() API makes a lot more sense.
While doing this, break out the printing of sequential compartment
lists into a helper function, mac_{biba,mls}_compartment_to_string().
This permits the main body of mac_{biba,mls}_element_to_string()
to be concerned only with identifying sequential ranges rather
than rendering.
At a less disruptive moment, we'll push the move from snprintf()-like
interface to sbuf()-like interface up into the MAC Framework layer.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
the vendor is only included in the long name currently, reducing
verbosity when modules are registered and unregistered.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
additional flags argument to indicate blocking disposition, and
pass in M_NOWAIT from the IP reassembly code to indicate that
blocking is not OK when labeling a new IP fragment reassembly
queue. This should eliminate some of the WITNESS warnings that
have started popping up since fine-grained IP stack locking
started going in; if memory allocation fails, the creation of
the fragment queue will be aborted.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
points available for enforcement:
mac_biba_check_sysarch_ioperm() - Require Biba privilege to make
use of privileged machine-dependent interfaces, protecting against
bypass of the policy via various mechanisms.
mac_biba_check_system_swapoff() - Require Biba privilege to disable
swapping against a vnode target.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
MAC policy. To load a KLD, require that the subject hold Biba privilege,
and the the kernel module be marked as high integrity. To unload a
KLD, require that the subject hold Biba privilege.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
and MLS policies: as we support both an effective (single) element and
range (available) elements, require that the single be in the range if
both the single and range are defined in the update. Remove comments
suggesting that such a check might be a good idea.
Don't introduce a similar check for network interfaces; due to different
interpretations of the single and range elements, it's not clear that
it's useful to do so.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
labeling for Biba.
Rename the variable 'level' to 'type' in interface parsing and
labeling for MLS.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
kernel, you should expect them to do something, so now they do. This
doesn't affect users who don't load or explicitly compile in the
policies.
Approved by: re (jhb)
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
unused. Replace it with a dm_mount back-pointer to the struct mount
that the devfs_mount is associated with. Export that pointer to MAC
Framework entry points, where all current policies don't use the
pointer. This permits the SEBSD port of SELinux's FLASK/TE to compile
out-of-the-box on 5.0-CURRENT with full file system labeling support.
Approved by: re (murray)
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
we brought in the new cache and locking model for vnode labels. We
now rely on mac_associate_devfs_vnode().
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
