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
require Biba privilege to configure either, and require that accounting
files be high integrity. Note that this does allow implicit information
flow from low to high integrity, but it also protects the integrity
of accounting data.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
function takes an int * parameter, not a size_t * parameter.
Arguably, it should rather take a size_t *, but that would
require changing the uio_resid field of struct uio to be a size_t
instead of an int, which I don't want to do that close to
5.0-RELEASE.
Reviewed by: rwatson
structure definition, rather than using an operation vector
we translate into the structure. Originally, we used a vector
for two reasons:
(1) We wanted to define the structure sparsely, which wasn't
supported by the C compiler for structures. For a policy
with five entry points, you don't want to have to stick in
a few hundred NULL function pointers.
(2) We thought it would improve ABI compatibility allowing modules
to work with kernels that had a superset of the entry points
defined in the module, even if the kernel had changed its
entry point set.
Both of these no longer apply:
(1) C99 gives us a way to sparsely define a static structure.
(2) The ABI problems existed anyway, due to enumeration numbers,
argument changes, and semantic mismatches. Since the going
rule for FreeBSD is that you really need your modules to
pretty closely match your kernel, it's not worth the
complexity.
This submit eliminates the operation vector, dynamic allocation
of the operation structure, copying of the vector to the
structure, and redoes the vectors in each policy to direct
structure definitions. One enourmous benefit of this change
is that we now get decent type checking on policy entry point
implementation arguments.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
MAC access() and open() checks, the argument actually has an int type
where it becomes available. Switch to using 'int' for the mode argument
throughout the MAC Framework and policy modules.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
and mac_check_system_sysctl(), providing additional integrity
protections relating to swap target device selection and system
management via sysctl(). Require Biba privilege for both; also
require that the target of swap operations be a high integrity
object, since swap data is high integrity.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Asssociates Laboratories
Print a warning if a requested interface name is longer than
IFNAMSIZ.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
"refreshing" the label on the vnode before use, just get the label
right from inception. For single-label file systems, set the label
in the generic VFS getnewvnode() code; for multi-label file systems,
leave the labeling up to the file system. With UFS1/2, this means
reading the extended attribute during vfs_vget() as the inode is
pulled off disk, rather than hitting the extended attributes
frequently during operations later, improving performance. This
also corrects sematics for shared vnode locks, which were not
previously present in the system. This chances the cache
coherrency properties WRT out-of-band access to label data, but in
an acceptable form. With UFS1, there is a small race condition
during automatic extended attribute start -- this is not present
with UFS2, and occurs because EAs aren't available at vnode
inception. We'll introduce a work around for this shortly.
Approved by: re
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
to parse their own label elements (some cleanup to occur here in the
future to use the newly added kernel strsep()). Policies now
entirely encapsulate their notion of label in the policy module.
Approved by: re
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
copy elements of one Biba or MLS label to another based on the flags
on the source label element. Use this instead of
mac_{biba,mls}_{single,range}() to simplify the existing code, as
well as support partial label updates (we don't update if none is
requested).
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
policies remains the same: subjects and objects are labeled for
integrity or sensitivity, and a dominance operator determines whether
or not subject/object accesses are permitted to limit inappropriate
information flow. Compartments are a non-hierarchal component to
the label, so add a bitfield to the label element for each, and a
set check as part of the dominance operator. This permits the
implementation of "need to know" elements of MLS.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
range on them, leaving process credentials as the only kernel
objects with label ranges in the Biba and MLS policies. We
weren't using the range in any access control decisions, so this
lets us garbage collect effectively unused code.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
collapse the two cases more cleanly: rather than wrapping an access
check around open, simply provide the open implementation for the
access vector entry. No functional change.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
we just break out some of the tests better. Minor change in that
we now better support incremental update of labels.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
instead of the default biba/high, mls/low, making it easier to use
ptys with these policies. This isn't the final solution, but does
help.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
seperate entry points for each occasion:
mac_check_vnode_mmap() Check at initial mapping
mac_check_vnode_mprotect() Check at mapping protection change
mac_check_vnode_mmap_downgrade() Determine if a mapping downgrade
should take place following
subject relabel.
Implement mmap() and mprotect() entry points for labeled vnode
policies. These entry points are currently not hooked up to the
VM system in the base tree. These changes improve the consistency
of the access control interface and offer more flexibility regarding
limiting access to vnode mmaping.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
flags so that we can call malloc with M_NOWAIT if necessary, avoiding
potential sleeps while holding mutexes in the TCP syncache code.
Similar to the existing support for mbuf label allocation: if we can't
allocate all the necessary label store in each policy, we back out
the label allocation and fail the socket creation. Sync from MAC tree.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
- Change mpo_init_foo(obj, label) and mpo_destroy_foo(obj, label) policy
entry points to mpo_init_foo_label(label) and
mpo_destroy_foo_label(label). This will permit the use of the same
entry points for holding temporary type-specific label during
internalization and externalization, as well as for caching purposes.
- Because of this, break out mpo_{init,destroy}_socket() and
mpo_{init,destroy}_mount() into seperate entry points for socket
main/peer labels and mount main/fs labels.
- Since the prototype for label initialization is the same across almost
all entry points, implement these entry points using common
implementations for Biba, MLS, and Test, reducing the number of
almost identical looking functions.
This simplifies policy implementation, as well as preparing us for the
merge of the new flexible userland API for managing labels on objects.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
