mac_reflect_mbuf_icmp()
mac_reflect_mbuf_tcp()
These entry points permit MAC policies to do "update in place"
changes to the labels on ICMP and TCP mbuf headers when an ICMP or
TCP response is generated to a packet outside of the context of
an existing socket. For example, in respond to a ping or a RST
packet to a SYN on a closed port.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
change in mac_lomac: if both flags are set on the new label, we
may not need to always fill out the label (only if one flag is
set, not both). Avoid stomping on a section of the label if we
are in fact modifying both elements.
Because we know that both flags will be set, we don't need to
test whether the range or single are set in later consistency
checks of the range and single -- just test them.
By checking the range of the new vs. the range of the old label
before testing the single against the new range, we implicitly
test that the new single is in the old range. Document this
with a comment.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
Framework labels:
- Re-work the label state assertions to use a set of central
ASSERT_type_LABEL() assertions.
- Test to make sure labels passed to externalize/internalize calls haven't
been destroyed.
- For access control checks, assert the condition of all labels passed in.
- For life cycle events, assert the condition of all labels passed in.
- Add new entry point implementations for new MAC Framework entry points:
mac_test_reflect_mbuf_icmp(), mac_test_reflect_mbuf_tcp(),
mac_test_check_vnode_deleteextattr(), mac_test_check_vnode_listextattr().
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
mac_stub policy and no longer mac_none (as found in the repocopy).
Add comment to this effect.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
explicit access control checks to delete and list extended attributes
on a vnode, rather than implicitly combining with the setextattr and
getextattr checks. This reflects EA API changes in the kernel made
recently, including the move to explicit VOP's for both of these
operations.
Obtained from: TrustedBSD PRoject
Sponsored by: DARPA, Network Associates Laboratories
MAC_DEBUG_COUNTER_INC() and MAC_DEBUG_COUNTER_DEC() to maintain
debugging counter values rather than #ifdef'ing the atomic
operations to MAC_DEBUG.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
mac_mls_subject_equal_ok() to mac_mls_subject_privileged(),
which more consistently reflects the fact that this is really
about our notion of privilege in the MLS policy.
Since we don't use suser() for privilege in MLS, remove
the suser check from the ifnet relabel ioctl, and replace it
with an MLS privilege check.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
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
policy definition structure; this permits policies to reduce their
number of gratuitous includes for required for entry points they
don't implement. This also facilitates building the MAC Framework
on Darwin.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
Several of the subtypes have an associated vnode which is used for
stuff like the f*() functions.
By giving the vnode a speparate field, a number of checks for the specific
subtype can be replaced simply with a check for f_vnode != NULL, and
we can later free f_data up to subtype specific use.
At this point in time, f_data still points to the vnode, so any code I
might have overlooked will still work.
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
mismerged from the MAC tree, and didn't get picked up because warnings
are not normally fatal in per-module builds, only when they are linked
into a kernel (such as LINT).
Reported by: des and the technicolor tinderbox
Approved by: re (scottl)
constants in question refer to the number of label slots, not the
maximum number of policies that may be loaded. This should reduce
confusion regarding an element in the MAC sysctl MIB, as well as
make it more clear what the affect of changing the compile-time
constants is.
Approved by: re (jhb)
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
(1) Accept that we're now going to use mutexes, so don't attempt
to avoid treating them as mutexes. This cleans up locking
accessor function names some.
(2) Rename variables to _mtx, _cv, _count, simplifying the naming.
(3) Add a new form of the _busy() primitive that conditionally
makes the list busy: if there are entries on the list, bump
the busy count. If there are no entries, don't bump the busy
count. Return a boolean indicating whether or not the busy
count was bumped.
(4) Break mac_policy_list into two lists: one with the same name
holding dynamic policies, and a new list, mac_static_policy_list,
which holds policies loaded before mac_late and without the
unload flag set. The static list may be accessed without
holding the busy count, since it can't change at run-time.
(5) In general, prefer making the list busy conditionally, meaning
we pay only one mutex lock per entry point if all modules are
on the static list, rather than two (since we don't have to
lower the busy count when we're done with the framework). For
systems running just Biba or MLS, this will halve the mutex
accesses in the network stack, and may offer a substantial
performance benefits.
(6) Lay the groundwork for a dynamic-free kernel option which
eliminates all locking associated with dynamically loaded or
unloaded policies, for pre-configured systems requiring
maximum performance but less run-time flexibility.
These changes have been running for a few weeks on MAC development
branch systems.
Approved by: re (jhb)
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
- Add a parameter to vm_pageout_flush() that tells vm_pageout_flush()
whether its caller has locked the vm_object. (This is a temporary
measure to bootstrap vm_object locking.)
blocking allocation could occur as a result of a label
initialization. This will simulate the behavior of allocated
label policies such as MLS and Biba when running mac_test from
the perspective of WITNESS lock and sleep warnings.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
don't try and convert the argument flags to malloc flags, or we risk
implicitly requesting blocking and generating witness warnings.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
returning some additional room in the first mbuf in a chain, and
avoiding feature-specific contents in the mbuf header. To do this:
- Modify mbuf_to_label() to extract the tag, returning NULL if not
found.
- Introduce mac_init_mbuf_tag() which does most of the work
mac_init_mbuf() used to do, except on an m_tag rather than an
mbuf.
- Scale back mac_init_mbuf() to perform m_tag allocation and invoke
mac_init_mbuf_tag().
- Replace mac_destroy_mbuf() with mac_destroy_mbuf_tag(), since
m_tag's are now GC'd deep in the m_tag/mbuf code rather than
at a higher level when mbufs are directly free()'d.
- Add mac_copy_mbuf_tag() to support m_copy_pkthdr() and related
notions.
- Generally change all references to mbuf labels so that they use
mbuf_to_label() rather than &mbuf->m_pkthdr.label. This
required no changes in the MAC policies (yay!).
- Tweak mbuf release routines to not call mac_destroy_mbuf(),
tag destruction takes care of it for us now.
- Remove MAC magic from m_copy_pkthdr() and m_move_pkthdr() --
the existing m_tag support does all this for us. Note that
we can no longer just zero the m_tag list on the target mbuf,
rather, we have to delete the chain because m_tag's will
already be hung off freshly allocated mbuf's.
- Tweak m_tag copying routines so that if we're copying a MAC
m_tag, we don't do a binary copy, rather, we initialize the
new storage and do a deep copy of the label.
- Remove use of MAC_FLAG_INITIALIZED in a few bizarre places
having to do with mbuf header copies previously.
- When an mbuf is copied in ip_input(), we no longer need to
explicitly copy the label because it will get handled by the
m_tag code now.
- No longer any weird handling of MAC labels in if_loop.c during
header copies.
- Add MPC_LOADTIME_FLAG_LABELMBUFS flag to Biba, MLS, mac_test.
In mac_test, handle the label==NULL case, since it can be
dynamically loaded.
In order to improve performance with this change, introduce the notion
of "lazy MAC label allocation" -- only allocate m_tag storage for MAC
labels if we're running with a policy that uses MAC labels on mbufs.
Policies declare this intent by setting the MPC_LOADTIME_FLAG_LABELMBUFS
flag in their load-time flags field during declaration. Note: this
opens up the possibility of post-boot policy modules getting back NULL
slot entries even though they have policy invariants of non-NULL slot
entries, as the policy might have been loaded after the mbuf was
allocated, leaving the mbuf without label storage. Policies that cannot
handle this case must be declared as NOTLATE, or must be modified.
- mac_labelmbufs holds the current cumulative status as to whether
any policies require mbuf labeling or not. This is updated whenever
the active policy set changes by the function mac_policy_updateflags().
The function iterates the list and checks whether any have the
flag set. Write access to this variable is protected by the policy
list; read access is currently not protected for performance reasons.
This might change if it causes problems.
- Add MAC_POLICY_LIST_ASSERT_EXCLUSIVE() to permit the flags update
function to assert appropriate locks.
- This makes allocation in mac_init_mbuf() conditional on the flag.
Reviewed by: sam
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
mbuf_to_label(). This permits the vast majority of entry point code
to be unaware that labels are stored in m->m_pkthdr.label, such that
we can experiment storage of labels elsewhere (such as in m_tags).
Reviewed by: sam
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
of asserting that an mbuf has a packet header. Use it instead of hand-
rolled versions wherever applicable.
Submitted by: Hiten Pandya <hiten@unixdaemons.com>
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
functionality for the following entry pints:
mac_test_init_proc_label()
mac_test_destroy_proc_label()
For process labeling entry points, now also track the use of process
labels and test assertions about their integrity and life cycle.
mac_test_thread_userret()
mac_test_check_kenv_dump()
mac_test_check_kenv_get()
mac_test_check_kenv_set()
mac_test_check_kenv_unset()
mac_test_check_kld_load()
mac_test_check_kld_stat()
mac_test_check_kld_unload()
mac_test_check_sysarch_ioperm()
mac_test_check_system_acct()
mac_test_check_system_reboot()
mac_test_check_system_settime()
mac_test_check_system_swapon()
mac_test_check_system_swapoff()
mac_test_check_system_sysctl()
For other entry points, just provide testing stubs.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
for enforcement:
mac_mls_check_system_swapon() - Require that the subject and the
swapfile target vnode labels dominate one another. An additional
check is probably needed here to require that the swapfile target
has a label of mls/high to prevent information leakage through
swapfiles.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
include a new entry point available for enforcement:
mac_bsdextended_check_system_swapon() - Apply extended access
control checks to the file target of swap.
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
which are no longer required now that we have UFS2 with extended
attribute transactions.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
check, mac_check_sysarch_ioperm(), permitting MAC security policy
modules to control access to these interfaces. Currently, they
protect access to IOPL on i386, and setting HAE on Alpha.
Additional checks might be required on other platforms to prevent
bypass of kernel security protections by unauthorized processes.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
modules to authorize disabling of swap against a particular vnode.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
