Commit Graph

69 Commits

Author SHA1 Message Date
Robert Watson
2555374c4f Introduce p_label, extensible security label storage for the MAC framework
in struct proc.  While the process label is actually stored in the
struct ucred pointed to by p_ucred, there is a need for transient
storage that may be used when asynchronous (deferred) updates need to
be performed on the "real" label for locking reasons.  Unlike other
label storage, this label has no locking semantics, relying on policies
to provide their own protection for the label contents, meaning that
a policy leaf mutex may be used, avoiding lock order issues.  This
permits policies that act based on historical process behavior (such
as audit policies, the MAC Framework port of LOMAC, etc) can update
process properties even when many existing locks are held without
violating the lock order.  No currently committed policies implement use
of this label storage.

Approved by:	re
Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-11-20 15:41:25 +00:00
Robert Watson
a3df768b04 Merge kld access control checks from the MAC tree: these access control
checks permit policy modules to augment the system policy for permitting
kld operations.  This permits policies to limit access to kld operations
based on credential (and other) properties, as well as to perform checks
on the kld being loaded (integrity, etc).

Approved by:	re
Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-11-19 22:12:42 +00:00
Robert Watson
a96acd1ace Introduce a condition variable to avoid returning EBUSY when
the MAC policy list is busy during a load or unload attempt.
We assert no locks held during the cv wait, meaning we should
be fairly deadlock-safe.  Because of the cv model and busy
count, it's possible for a cv waiter waiting for exclusive
access to the policy list to be starved by active and
long-lived access control/labeling events.  For now, we
accept that as a necessary tradeoff.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-11-13 15:47:09 +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
2d43d24ed4 Garbage collect definition of M_MACOPVEC -- we no longer perform a
dynamic mapping of an operation vector into an operation structure,
rather, we rely on C99 sparse structure initialization.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-11-11 14:15:58 +00:00
Robert Watson
9fa3506ecd Add an explicit execlabel argument to exec-related MAC policy entry
points, rather than relying on policies to grub around in the
image activator instance structure.

Approved by:	re
Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-11-08 18:04:00 +00:00
Robert Watson
670cb89bf4 Bring in two sets of changes:
(1) Permit userland applications to request a change of label atomic
    with an execve() via mac_execve().  This is required for the
    SEBSD port of SELinux/FLASK.  Attempts to invoke this without
    MAC compiled in result in ENOSYS, as with all other MAC system
    calls.  Complexity, if desired, is present in policy modules,
    rather than the framework.

(2) Permit policies to have access to both the label of the vnode
    being executed as well as the interpreter if it's a shell
    script or related UNIX nonsense.  Because we can't hold both
    vnode locks at the same time, cache the interpreter label.
    SEBSD relies on this because it supports secure transitioning
    via shell script executables.  Other policies might want to
    take both labels into account during an integrity or
    confidentiality decision at execve()-time.

Approved by:	re
Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-11-05 17:51:56 +00:00
Robert Watson
4443e9ff4a Assert that appropriate vnodes are locked in mac_execve_will_transition().
Allow transitioning to be twiddled off using the process and fs enforcement
flags, although at some point this should probably be its own flag.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-11-05 15:11:33 +00:00
Robert Watson
e5e820fd1f Permit MAC policies to instrument the access control decisions for
system accounting configuration and for nfsd server thread attach.
Policies might use this to protect the integrity or confidentiality
of accounting data, limit the ability to turn on or off accounting,
as well as to prevent inappropriately labeled threads from becoming nfs
server threads.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-11-04 15:13:36 +00:00
Robert Watson
3da87a65c7 Remove mac_cache_fslabel_in_vnode sysctl -- with the new VFS/MAC
construction, labels are always cached.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-11-04 14:55:14 +00:00
Robert Watson
6201265be7 License clarification and wording changes: NAI has approved removal of
clause three, and NAI Labs now goes by the name Network Associates
Laboratories.
2002-11-04 01:42:39 +00:00
Robert Watson
4b8d5f2d97 Introduce mac_check_system_settime(), a MAC check allowing policies to
augment the system policy for changing the system time.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-11-03 02:39:42 +00:00
Robert Watson
e686e5ae91 Add MAC checks for various kenv() operations: dump, get, set, unset,
permitting MAC policies to limit access to the kernel environment.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-11-01 20:46:53 +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
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
8b3a843438 An inappropriate ASSERT slipped in during the recent merge of the
reboot checking; remove.
2002-10-28 18:53:53 +00:00
Robert Watson
9e913ebd0a Centrally manage enforcement of {reboot,swapon,sysctl} using the
mac_enforce_system toggle, rather than several separate toggles.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-27 15:50:49 +00:00
Robert Watson
d3fc69ee6a Implement mac_check_system_sysctl(), a MAC Framework entry point to
permit MAC policies to augment the security protections on sysctl()
operations.  This is not really a wonderful entry point, as we
only have access to the MIB of the target sysctl entry, rather than
the more useful entry name, but this is sufficient for policies
like Biba that wish to use their notions of privilege or integrity
to prevent inappropriate sysctl modification.  Affects MAC kernels
only.  Since SYSCTL_LOCK isn't in sysctl.h, just kern_sysctl.c,
we can't assert the SYSCTL subsystem lockin the MAC Framework.

Approved by:	re
Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-27 07:12:34 +00:00
Robert Watson
a2ecb9b790 Hook up mac_check_system_reboot(), a MAC Framework entry point that
permits MAC modules to augment system security decisions regarding
the reboot() system call, if MAC is compiled into the kernel.

Approved by:	re
Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-27 07:03:29 +00:00
Robert Watson
03ce2c0c9b Merge from MAC tree: rename mac_check_vnode_swapon() to
mac_check_system_swapon(), to reflect the fact that the primary
object of this change is the running kernel as a whole, rather
than just the vnode.  We'll drop additional checks of this
class into the same check namespace, including reboot(),
sysctl(), et al.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-27 06:54:06 +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
a67fe518a1 Comment describing the semantics of mac_late.
Trim trailing whitespace.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-25 20:45:27 +00:00
Robert Watson
1cbfd977fd Introduce MAC_CHECK_VNODE_SWAPON, which permits MAC policies to
perform authorization checks during swapon() events; policies
might choose to enforce protections based on the credential
requesting the swap configuration, the target of the swap operation,
or other factors such as internal policy state.

Approved by:	re
Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-22 15:53:43 +00:00
Robert Watson
2789e47e2c Missed in previous merge: export sizeof(struct oldmac) rather than
sizeof(struct mac).

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-22 15:33:33 +00:00
Robert Watson
f7b951a8e0 Support the new MAC user API in kernel: modify existing system calls
to use a modified notion of 'struct mac', and flesh out the new variation
system calls (almost identical to existing ones except that they permit
a pid to be specified for process label retrieval, and don't follow
symlinks).  This generalizes the label API so that the framework is
now almost entirely policy-agnostic.

Approved by:	re
Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-22 14:29:47 +00:00
Brooks Davis
29e1b85f97 Use if_printf(ifp, "blah") instead of
printf("%s%d: blah", ifp->if_name, ifp->if_xname).
2002-10-21 02:51:56 +00:00
Robert Watson
a13c67da35 If MAC_MAX_POLICIES isn't defined, don't try to define it, just let the
compile fail.  MAC_MAX_POLICIES should always be defined, or we have
bigger problems at hand.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-20 03:41:09 +00:00
Robert Watson
9aeffb2b28 Make sure to clear the 'registered' flag for MAC policies when they
unregister.  Under some obscure (perhaps demented) circumstances,
this can result in a panic if a policy is unregistered, and then someone
foolishly unregisters it again.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-19 20:30:12 +00:00
Robert Watson
b371c939ce Integrate mac_check_socket_send() and mac_check_socket_receive()
checks from the MAC tree: allow policies to perform access control
for the ability of a process to send and receive data via a socket.
At some point, we might also pass in additional address information
if an explicit address is requested on send.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-06 14:39:15 +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
74e62b1b75 Integrate a devfs/MAC fix from the MAC tree: avoid a race condition during
devfs VOP symlink creation by introducing a new entry point to determine
the label of the devfs_dirent prior to allocation of a vnode for the
symlink.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-05 18:40:10 +00:00
Robert Watson
0a69419678 Merge support for mac_check_vnode_link(), a MAC framework/policy entry
point that instruments the creation of hard links.  Policy implementations
to follow.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-05 18:11:36 +00:00
Robert Watson
56c1541237 While the MAC API has supported the ability to handle M_NOWAIT passed
to mbuf label initialization, that functionality was never merged to
the main tree.  Go ahead and merge that functionality now.  Note that
this requires policy modules to accept the case where the label
element may be destroyed even if init has not succeeded on it (in
the event that policy failed the init).  This will shortly also
apply to sockets.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-05 17:44:49 +00:00
Robert Watson
87807196f8 Rearrange object and label init/destroy functions to match the
order used in mac_policy.h and elsewhere.  Sort order is basically
"by operation category", then "alphabetically by object". Sync to
MAC tree.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-05 17:38:45 +00:00
Robert Watson
a931e345a9 Sync to MAC tree: use 'flag' instead of 'how' for mac_init_mbuf();
remove a slightly less than useful comment.
2002-10-05 17:18:43 +00:00
Robert Watson
69bbb5b1c7 Another big diff, little functional change: move label internalization,
externalization, and cred label life cycle events to entirely above
devfs and vnode events.  Sync from MAC tree.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-05 16:57:16 +00:00
Robert Watson
08bcdc586e Move all object label init/destroy routines to the head of the
entry points to better match the entry point ordering in mac_policy.h.
Big diff, no functional change; merge from the MAC tree.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-05 16:54:59 +00:00
Robert Watson
ea599aa018 Synch from TrustedBSD MAC tree:
- If a policy isn't registered when a policy module unloads, silently
  succeed.

- Hold the policy list lock across more of the validity tests to avoid
  races.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-05 16:46:03 +00:00
Robert Watson
226b96fb6d Cosmetic line wrap synchronization. 2002-10-05 16:33:46 +00:00
Robert Watson
b2f0927ad6 Push the debugging obect label counters into security.mac.debug.counters
rather than directly under security.mac.debug.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-05 16:30:53 +00:00
Robert Watson
96adb90996 Begin another merge from the TrustedBSD MAC branch:
- 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
2002-10-05 15:10:00 +00:00
Robert Watson
92dbb82a47 Add a new MAC entry point, mac_thread_userret(td), which permits policy
modules to perform MAC-related events when a thread returns to user
space.  This is required for policies that have floating process labels,
as it's not always possible to acquire the process lock at arbitrary
points in the stack during system call processing; process labels might
represent traditional authentication data, process history information,
or other data.

LOMAC will use this entry point to perform the process label update
prior to the thread returning to userspace, when plugged into the MAC
framework.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-02 02:42:38 +00:00
Poul-Henning Kamp
328048bc56 Remember to include "opt_devfs.h" so we get any relevant changes
to NDEVFSINO before we include devfs.h.

Spotted by:	FlexeLint
2002-10-01 15:24:35 +00:00
Robert Watson
1aa37f5392 Improve locking of pipe mutexes in the context of MAC:
(1) Where previously the pipe mutex was selectively grabbed during
    pipe_ioctl(), now always grab it and then release if if not
    needed.  This protects the call to mac_check_pipe_ioctl() to
    make sure the label remains consistent.  (Note: it looks
    like sigio locking may be incorrect for fgetown() since we
    call it not-by-reference and sigio locking assumes call by
    reference).

(2) In pipe_stat(), lock the pipe if MAC is compiled in so that
    the call to mac_check_pipe_stat() gets a locked pipe to
    protect label consistency.  We still release the lock before
    returning actual stat() data, risking inconsistency, but
    apparently our pipe locking model accepts that risk.

(3) In various pipe MAC authorization checks, assert that the pipe
    lock is held.

(4) Grab the lock when performing a pipe relabel operation, and
    assert it a little deeper in the stack.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-01 04:30:19 +00:00
Robert Watson
6be0c25e4e Push 'security.mac.debug_label_fallback' behind options MAC_DEBUG.
Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, NAI Labs
2002-10-01 03:24:20 +00:00
Robert Watson
c031391bd5 Add tunables for the existing sysctl twiddles for pipe and vm
enforcement so they can be disabled prior to kernel start.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-09-30 20:50:00 +00:00
Robert Watson
cc51a2b55e Remove un-needed stack variable 'ops'.
Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-09-18 22:35:02 +00:00
Robert Watson
ca7850c313 Add a toggle to disable VM enforcement.
Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, NAI Labs
2002-09-18 02:02:08 +00:00
Robert Watson
b88c98f6b1 At the cost of seeming a little gauche, make use of more traditional
alphabetization for mac_enforce_pipe sysctl.

Obtained from:	TrustedBSD Project
Sponsored by:	DAPRA, NAI Labs
2002-09-18 02:00:19 +00:00