(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
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
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
permitting MAC policies to limit access to the kernel environment.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
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
mac_enforce_system toggle, rather than several separate toggles.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
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
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
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
"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
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
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
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
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
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
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
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
point that instruments the creation of hard links. Policy implementations
to follow.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
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
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
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
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
- 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
- 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
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
(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
v_tag is now const char * and should only be used for debugging.
Additionally:
1. All users of VT_NTS now check vfsconf->vf_type VFCF_NETWORK
2. The user of VT_PROCFS now checks for the new flag VV_PROCDEP, which
is propagated by pseudofs to all child vnodes if the fs sets PFS_PROCDEP.
Suggested by: phk
Reviewed by: bde, rwatson (earlier version)
layers deep in <sys/proc.h> or <sys/vnode.h>.
Removed unused includes.
Fixed some printf format errors (1 fatal on i386's; 1 fatal on alphas;
1 not fatal on any supported machine).
proc locking when revoking access to mmaps. Instead, perform this
later once we've changed the process label (hold onto a reference
to the new cred so that we don't lose it when we release the
process lock if another thread changes the credential).
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
for mac_check_vnode_{poll,read,stat,write}(). Pass in fp->f_cred
when calling these checks with a struct file available. Otherwise,
pass NOCRED. All currently MAC policies use active_cred, but
could now offer the cached credential semantic used for the base
system security model.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
can offer new services without reserving system call numbers, or
augmented versions of existing services. User code requests a
target policy by name, and specifies the policy-specific API plus
target. This is required in particular for our port of SELinux/FLASK
to the MAC framework since it offers additional security services.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
mac_check_pipe_poll(), mac_check_pipe_read(), mac_check_pipe_stat(),
and mac_check_pipe_write(). This is improves consistency with other
access control entry points and permits security modules to only
control the object methods that they are interested in, avoiding
switch statements.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
mac_check_vnode_poll(), mac_check_vnode_read(), mac_check_vnode_write().
This improves the consistency with other existing vnode checks, and
allows policies to avoid implementing switch statements to determine
what operations they do and do not want to authorize.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
can avoid the cost of a large number of atomic operations if we're not
interested in the object count statistics.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
we can use the names _receive() and _send() for the receive() and send()
checks. Rename related constants, policy implementations, etc.
PR:
Submitted by:
Reviewed by:
Approved by:
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
MFC after:
during a label change resulting in an mmap removal. This is "fail stop"
behavior, which is preferred, although it offers slightly less
transparency.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
enabled and the kernel provides the MAC registration and entry point
service. Declare a dependency on that module service for any
MAC module registered using mac_policy.h. For now, hard code the
version as 1, but once we've come up with a versioning policy, we'll
move to a #define of some sort. In the mean time, this will prevent
loading a MAC module when 'options MAC' isn't present, which (due to
a bug in the kernel linker) can result if the MAC module is preloaded
via loader.conf.
This particular evil recommended by: peter
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI LAbs
- v_vflag is protected by the vnode lock and is used when synchronization
with VOP calls is needed.
- v_iflag is protected by interlock and is used for dealing with vnode
management issues. These flags include X/O LOCK, FREE, DOOMED, etc.
- All accesses to v_iflag and v_vflag have either been locked or marked with
mp_fixme's.
- Many ASSERT_VOP_LOCKED calls have been added where the locking was not
clear.
- Many functions in vfs_subr.c were restructured to provide for stronger
locking.
Idea stolen from: BSD/OS
kernel access control. The MAC framework permits loadable kernel
modules to link to the kernel at compile-time, boot-time, or run-time,
and augment the system security policy. This commit includes the
initial kernel implementation, although the interface with the userland
components of the oeprating system is still under work, and not all
kernel subsystems are supported. Later in this commit sequence,
documentation of which kernel subsystems will not work correctly with
a kernel compiled with MAC support will be added.
kern_mac.c contains the body of the MAC framework. Kernel and
user APIs defined in mac.h are implemented here, providing a front end
to loaded security modules. This code implements a module registration
service, state (label) management, security configuration and policy
composition.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
