Commit Graph

63 Commits

Author SHA1 Message Date
Robert Watson
f51e58036e Redesign the externalization APIs from the MAC Framework to
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
2003-06-23 01:26:34 +00:00
Robert Watson
f32bb0529b Use mac_biba_label_copy() and mac_mls_label_copy() to implement the
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
2003-06-02 17:21:38 +00:00
Robert Watson
05e830f1e7 Rewrite Biba and MLS label externalization code to use sbufs instead
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
2003-05-31 19:01:44 +00:00
Robert Watson
7792fe5719 Use strsep() in preference to manual string parsing for Biba and MLS
label internalization.  Use sensible variable names.  Include comments.
Doesn't fix any known bugs, but may fix unknown ones.

Approved by:	re (scottl)
2003-05-29 22:51:52 +00:00
Robert Watson
9a1b0237a7 Enable the MAC_ALWAYS_LABEL_MBUF flag for the Biba, LOMAC, MLS, and Test
policies.  Missed in earlier merge.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2003-04-15 20:51:18 +00:00
Robert Watson
78183ac2d2 Trim "trustedbsd_" from the front of the policy module "short names";
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
2003-03-27 19:26:39 +00:00
Robert Watson
5e7ce4785f Modify the mac_init_ipq() MAC Framework entry point to accept an
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
2003-03-26 15:12:03 +00:00
Robert Watson
2b03c68008 Expand scope of the Biba policy to include some of the new entry
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
2003-03-25 01:10:54 +00:00
Warner Losh
a163d034fa Back out M_* changes, per decision of the TRB.
Approved by: trb
2003-02-19 05:47:46 +00:00
Robert Watson
793274cecf Implement mpo_check_kld_load() and mpo_check_kld_unload() for the Biba
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
2003-02-04 22:38:33 +00:00
Robert Watson
12613c76cc Place more stringent checks on process credential relabeling for the Biba
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
2003-02-04 21:28:46 +00:00
Robert Watson
4d2ec8debb Rename the variable 'grade' to 'type' in interface parsing and
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
2003-02-04 21:00:51 +00:00
Alfred Perlstein
44956c9863 Remove M_TRYWAIT/M_WAITOK/M_WAIT. Callers should use 0.
Merge M_NOWAIT/M_DONTWAIT into a single flag M_NOWAIT.
2003-01-21 08:56:16 +00:00
Robert Watson
eba0370d90 Default policies to on: if you load them or compile them into your
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
2002-12-10 16:20:34 +00:00
Robert Watson
990b4b2dc5 Remove dm_root entry from struct devfs_mount. It's never set, and is
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
2002-12-09 03:44:28 +00:00
Robert Watson
63b6f478ec Garbage collect mac_create_devfs_vnode() -- it hasn't been used since
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
2002-11-12 04:20:36 +00:00
Robert Watson
ef5def596d Update MAC modules for changes in arguments for exec MAC policy
entry points to include an explicit execlabel.

Approved by:	re
Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-11-08 18:04:36 +00:00
Robert Watson
939b97cba6 Update policy modules for changes in arguments associated with support
for label access on the interpreter, not just the shell script.  No
policies currently present in the system rely on the new labels.
2002-11-05 17:52:42 +00:00
Robert Watson
b317d6f0aa Since neither the Biba policy nor the MLS policy make use of
transitioning, remove their transition entry points.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-11-05 16:44:29 +00:00
Robert Watson
743d9c6a2d Implement mpo_check_system_acct and mpo_check_system_settime() for Biba:
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
2002-11-04 17:50:52 +00:00
Robert Watson
1980cf9b79 Correct use of mac_biba_subject_privileged() in swapon() code.
Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-11-04 17:36:47 +00:00
Robert Watson
dc858fcabe License and wording updates: NAI has authorized the removal of clause
three from their BSD-style license.  Also, s/NAI Labs/Network Associates
Laboratories/.
2002-11-04 01:53:12 +00:00
Maxime Henrion
e6faed4db0 Fix some warnings on 64 bit architectures. The vn_extattr_get()
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
2002-11-02 20:16:35 +00:00
Robert Watson
5c8dd34218 Move to C99 sparse structure initialization for the mac_policy_ops
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
2002-10-30 18:48:51 +00:00
Robert Watson
1979061b56 Various minor type, prototype tweaks -- clean up cruft due to lack of
type checking on entry points (to be introduced shortly).

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-30 18:10:46 +00:00
Robert Watson
b914de36c0 While 'mode_t' seemed like a good idea for the access mode argument for
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
2002-10-30 17:56:57 +00:00
Robert Watson
26590ca793 Try again to fix the KASSERT. 2002-10-30 00:16:59 +00:00
Robert Watson
c7c2a7954a Fix a KASSERT bug that showed up only in the LINT build, not the
module build, so I missed it in the merge.

Pointed out by:	sam
2002-10-30 00:04:31 +00:00
Robert Watson
84c7715ec3 Implement Biba policy entry points for mac_check_system_swapon()
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
2002-10-29 19:18:52 +00:00
Robert Watson
757db56952 Require Biba privilege to relabel a network interface.
Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-29 19:14:16 +00:00
Robert Watson
f30a9615fd Remove all reference to 'struct oldmac', since it's no longer required
with the new VFS/EA semantics in the MAC framework.  Move the per-policy
structures out to per-policy include files, removing all policy-specific
defines and structures out of the base framework includes and
implementation, making mac_biba and mac_mls entirely self-contained.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-28 19:44:05 +00:00
Robert Watson
6d65e3d4ca Add a return type for mac_biba_high_single(), apparently lost in an
earlier merge.  It's a 'static int'.
2002-10-28 19:18:29 +00:00
Robert Watson
566d99847b Rename mac_biba_subject_equal_ok() to mac_biba_subject_privileged()
to evolve the notion of Biba privilege a bit.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-28 19:17:39 +00:00
Robert Watson
ee3bf1710a Zero the trusted_interface buffer before starting parsing.
Print a warning if a requested interface name is longer than
IFNAMSIZ.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-28 19:16:44 +00:00
Robert Watson
763bbd2f4f Slightly change the semantics of vnode labels for MAC: rather than
"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
2002-10-26 14:38:24 +00:00
Robert Watson
103bcded1d Style fix: space between 'switch' and '('. 2002-10-22 19:01:49 +00:00
Robert Watson
f6f5401f61 Don't enforce MAC Biba policy for socket visibility if Biba is not
explicitly enabled.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-22 17:02:42 +00:00
Robert Watson
24e8d0d07b Adapt MAC policies for the new user API changes; teach policies how
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
2002-10-22 14:31:34 +00:00
Robert Watson
36cf29fd8d Introduce mac_biba_copy() and mac_mls_copy(), which conditionally
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
2002-10-21 20:55:39 +00:00
Robert Watson
2a1c79af92 Add compartment support to Biba and MLS policies. The logic of the
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
2002-10-21 18:42:01 +00:00
Robert Watson
2f7f04362b Demote sockets to single-label objects rather than maintaining a
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
2002-10-21 18:05:12 +00:00
Robert Watson
6157bb02e8 Synchonize variable spelling with the MAC tree: we shortened some of
the names.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-21 17:05:48 +00:00
Robert Watson
b7c2a7f406 Since the Biba and MLS access checks are identical to the open checks,
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
2002-10-21 16:39:12 +00:00
Robert Watson
b5f072b5e1 Cleanup of relabel authorization checks -- almost identical logic,
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
2002-10-21 16:35:54 +00:00
Robert Watson
0b9b85b91d Add a twiddle to create PTY's with a biba/equal or mls/equal label
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
2002-10-21 04:15:40 +00:00
Robert Watson
82c6ef299e Trim accidentally introduced trailing whitespace. 2002-10-06 13:11:01 +00:00
Robert Watson
e183f80e54 Sync from MAC tree: break out the single mmap entry point into
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
2002-10-06 02:46:26 +00:00
Robert Watson
83985c267e Modify label allocation semantics for sockets: pass in soalloc's malloc
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
2002-10-05 21:23:47 +00:00
Robert Watson
eea8ea3108 Implement mac_create_devfs_symlink() for policies that interact with
vnode labels.  Sync from MAC tree.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-05 18:56:25 +00:00
Robert Watson
c27b50f5b4 Merge implementation of mpo_check_vnode_link() for various appropriate
file-system aware MAC policies.  Sync to MAC tree.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-05 18:25:48 +00:00