specific privilege names to a broad range of privileges. These may
require some future tweaking.
Sponsored by: nCircle Network Security, Inc.
Obtained from: TrustedBSD Project
Discussed on: arch@
Reviewed (at least in part) by: mlaier, jmg, pjd, bde, ceri,
Alex Lyashkov <umka at sevcity dot net>,
Skip Ford <skip dot ford at verizon dot net>,
Antoine Brodin <antoine dot brodin at laposte dot net>
privilege for threads and credentials. Unlike the existing suser(9)
interface, priv(9) exposes a named privilege identifier to the privilege
checking code, allowing more complex policies regarding the granting of
privilege to be expressed. Two interfaces are provided, replacing the
existing suser(9) interface:
suser(td) -> priv_check(td, priv)
suser_cred(cred, flags) -> priv_check_cred(cred, priv, flags)
A comprehensive list of currently available kernel privileges may be
found in priv.h. New privileges are easily added as required, but the
comments on adding privileges found in priv.h and priv(9) should be read
before doing so.
The new privilege interface exposed sufficient information to the
privilege checking routine that it will now be possible for jail to
determine whether a particular privilege is granted in the check routine,
rather than relying on hints from the calling context via the
SUSER_ALLOWJAIL flag. For now, the flag is maintained, but a new jail
check function, prison_priv_check(), is exposed from kern_jail.c and used
by the privilege check routine to determine if the privilege is permitted
in jail. As a result, a centralized list of privileges permitted in jail
is now present in kern_jail.c.
The MAC Framework is now also able to instrument privilege checks, both
to deny privileges otherwise granted (mac_priv_check()), and to grant
privileges otherwise denied (mac_priv_grant()), permitting MAC Policy
modules to implement privilege models, as well as control a much broader
range of system behavior in order to constrain processes running with
root privilege.
The suser() and suser_cred() functions remain implemented, now in terms
of priv_check() and the PRIV_ROOT privilege, for use during the transition
and possibly continuing use by third party kernel modules that have not
been updated. The PRIV_DRIVER privilege exists to allow device drivers to
check privilege without adopting a more specific privilege identifier.
This change does not modify the actual security policy, rather, it
modifies the interface for privilege checks so changes to the security
policy become more feasible.
Sponsored by: nCircle Network Security, Inc.
Obtained from: TrustedBSD Project
Discussed on: arch@
Reviewed (at least in part) by: mlaier, jmg, pjd, bde, ceri,
Alex Lyashkov <umka at sevcity dot net>,
Skip Ford <skip dot ford at verizon dot net>,
Antoine Brodin <antoine dot brodin at laposte dot net>
sockaddr_storage. This structure is defined in RFC 2553 and is a more
semantically correct structure for holding IP and IP6 sockaddr information.
struct sockaddr is not big enough to hold all the required information for
IP6, resulting in truncated addresses et al when auditing IP6 sockaddr
information.
We also need to assume that the sa->sa_len has been validated before the call to
audit_arg_sockaddr() is made, otherwise it could result in a buffer overflow.
This is being done to accommodate auditing of network related arguments (like
connect, bind et al) that will be added soon.
Discussed with: rwatson
Obtained from: TrustedBSD Project
MFC after: 2 weeks
begun with a repo-copy of mac.h to mac_framework.h. sys/mac.h now
contains the userspace and user<->kernel API and definitions, with all
in-kernel interfaces moved to mac_framework.h, which is now included
across most of the kernel instead.
This change is the first step in a larger cleanup and sweep of MAC
Framework interfaces in the kernel, and will not be MFC'd.
Obtained from: TrustedBSD Project
Sponsored by: SPARTA
not trust jails enough to execute audit related system calls. An example of
this is with su(1), or login(1) within prisons. So, if the syscall request
comes from a jail return ENOSYS. This will cause these utilities to operate
as if audit is not present in the kernel.
Looking forward, this problem will be remedied by allowing non privileged
users to maintain and their own audit streams, but the details on exactly how
this will be implemented needs to be worked out.
This change should fix situations when options AUDIT has been compiled into
the kernel, and utilities like su(1), or login(1) fail due to audit system
call failures within jails.
This is a RELENG_6 candidate.
Reported by: Christian Brueffer
Discussed with: rwatson
MFC after: 3 days
written to the audit trail file:
- audit_record_write() now returns void, and all file system specific
error handling occurs inside this function. This pushes error handling
complexity out of the record demux routine that hands off to both the
trail and audit pipes, and makes trail behavior more consistent with
pipes as a record destination.
- Rate limit kernel printfs associated with running low on space. Rate
limit audit triggers for low space. Rate limit printfs for fail stop
events. Rate limit audit worker write error printfs.
- Document in detail the types of limits and space checks we perform, and
combine common cases.
This improves the audit subsystems tolerance to low space conditions by
avoiding toasting the console with printfs are waking up the audit daemon
continuously.
MFC after: 3 days
Obtained from: TrustedBSD Project
other problems while labels were first being added to various kernel
objects. They have outlived their usefulness.
MFC after: 1 month
Suggested by: Christopher dot Vance at SPARTA dot com
Obtained from: TrustedBSD Project
when allocating the record in the first place, allocate the final buffer
when closing the BSM record. At that point, more size information is
available, so a sufficiently large buffer can be allocated.
This allows the kernel to generate audit records in excess of
MAXAUDITDATA bytes, but is consistent with Solaris's behavior. This only
comes up when auditing command line arguments, in which case we presume
the administrator really does want the data as they have specified the
policy flag to gather them.
Obtained from: TrustedBSD Project
MFC after: 3 days
with other commonly used sysctl name spaces, rather than declaring them
all over the place.
MFC after: 1 month
Sponsored by: nCircle Network Security, Inc.
audit pipes. If the kernel record was not selected for the trail or the pipe,
any user supplied record attached to it would be tossed away, resulting in
otherwise selected events being lost.
- Introduce two new masks: AR_PRESELECT_USER_TRAIL AR_PRESELECT_USER_PIPE,
currently we have AR_PRESELECT_TRAIL and AR_PRESELECT_PIPE, which tells
the audit worker that we are interested in the kernel record, with
the additional masks we can determine if either the pipe or trail is
interested in seeing the kernel or user record.
- In audit(2), we unconditionally set the AR_PRESELECT_USER_TRAIL and
AR_PRESELECT_USER_PIPE masks under the assumption that userspace has
done the preselection [1].
Currently, there is work being done that allows the kernel to parse and
preselect user supplied records, so in the future preselection could occur
in either layer. But there is still a few details to work out here.
[1] At some point we need to teach au_preselect(3) about the interests of
all the individual audit pipes.
This is a RELENG_6 candidate.
Reviewed by: rwatson
Obtained from: TrustedBSD Project
MFC after: 1 week
exists to allow the mandatory access control policy to properly initialize
mbufs generated by the firewall. An example where this might happen is keep
alive packets, or ICMP error packets in response to other packets.
This takes care of kernel panics associated with un-initialize mbuf labels
when the firewall generates packets.
[1] I modified this patch from it's original version, the initial patch
introduced a number of entry points which were programmatically
equivalent. So I introduced only one. Instead, we should leverage
mac_create_mbuf_netlayer() which is used for similar situations,
an example being icmp_error()
This will minimize the impact associated with the MFC
Submitted by: mlaier [1]
MFC after: 1 week
This is a RELENG_6 candidate
Add the argument auditing functions for argv and env.
Add kernel-specific versions of the tokenizer functions for the
arg and env represented as a char array.
Implement the AUDIT_ARGV and AUDIT_ARGE audit policy commands to
enable/disable argv/env auditing.
Call the argument auditing from the exec system calls.
Obtained from: TrustedBSD Project
Approved by: rwatson (mentor)
is loaded. This problem stems from the fact that the policy is not properly
initializing the mac label associated with the NFS daemon.
Obtained from: TrustedBSD Project
Discussed with: rwatson
audit record size at run-time, which can be used by the user
process to size the user space buffer it reads into from the audit
pipe.
Perforce change: 105098
Obtained from: TrustedBSD Project
progress the kernel audit code in CVS is considered authoritative.
This will ease $P4$-related merging issues during the CVS loopback.
Obtained from: TrustedBSD Project
we will initialize the label to biba/low for files that have been created
through an NFS RPC. This is a safe default given the default nature of our
NFS implementation, there is not a whole lot of data integrity there by
default. This also fixes kernel panics associated with file creation over NFS
while creating files on filesystems which have multilabel enabled with BIBA
enabled.
MFC after: 2 weeks
Discussed with: rwatson
- Correct audit_arg_socketaddr() argument name from so to sa.
- Assert arguments are non-NULL to many argument capture functions
rather than testing them. This may trip some bugs.
- Assert the process lock is held when auditing process
information.
- Test currecord in several more places.
- Test validity of more arguments with kasserts, such as flag
values when auditing vnode information.
Perforce change: 98825
Obtained from: TrustedBSD Project
whether we have an IPv6 address. Write the term ID as 4 or
16 bytes depending on address type. This change matches the recent
OpenBSM change, and what Solaris does.
Obtained from: TrustedBSD Project
Approved by: rwatson (mentor)
get a consistent snapshot, as well as get consistent values (i.e.,
that p_comm is properly nul-terminated).
Perforce CID: 98824
Obtained from: TrustedBSD Project
process was sucessfully audited. Otherwise, generate the PID
token. This change covers the pid < 0 cases, and pid lookup
failure cases.
Submitted by: wsalamon
Obtained from: TrustedBSD Project
global audit trail configuration. This allows applications consuming
audit trails to specify parameters for which audit records are of
interest, including selecting records not required by the global trail.
Allowing application interest specification without changing the global
configuration allows intrusion detection systems to run without
interfering with global auditing or each other (if multiple are
present). To implement this:
- Kernel audit records now carry a flag to indicate whether they have
been selected by the global trail or by the audit pipe subsystem,
set during record commit, so that this information is available
after BSM conversion when delivering the BSM to the trail and audit
pipes in the audit worker thread asynchronously. Preselection by
either record target will cause the record to be kept.
- Similar changes to preselection when the audit record is created
when the system call is entering: consult both the global trail and
pipes.
- au_preselect() now accepts the class in order to avoid repeatedly
looking up the mask for each preselection test.
- Define a series of ioctls that allow applications to specify whether
they want to track the global trail, or program their own
preselection parameters: they may specify their own flags and naflags
masks, similar to the global masks of the same name, as well as a set
of per-auid masks. They also set a per-pipe mode specifying whether
they track the global trail, or user their own -- the door is left
open for future additional modes. A new ioctl is defined to allow a
user process to flush the current audit pipe queue, which can be used
after reprogramming pre-selection to make sure that only records of
interest are received in future reads.
- Audit pipe data structures are extended to hold the additional fields
necessary to support preselection. By default, audit pipes track the
global trail, so "praudit /dev/auditpipe" will track the global audit
trail even though praudit doesn't program the audit pipe selection
model.
- Comment about the complexities of potentially adding partial read
support to audit pipes.
By using a set of ioctls, applications can select which records are of
interest, and toggle the preselection mode.
Obtained from: TrustedBSD Project
knowledge of user vs. kernel audit records into
audit_worker_process_record(). This largely confines vnode
knowledge to audit_record_write(), but avoids that logic knowing
about BSM as opposed to byte streams. This will allow us to
improve our ability to support real-time audit stream processing
by audit pipe consumers while auditing is disabled, but this
support is not yet complete.
Obtained from: TrustedBSD Project
Break out logic to call audit_record_write() and handle error
conditions into audit_worker_process_record(). This will be the
future home of some logic now present in audit_record_write()
also.
Obtained from: TrustedBSD Project
worker.
Rename audit_commit_cv to audit_watermark_cv, since it is there to
wake up threads waiting on hitting the low watermark. Describe
properly in comment.
Obtained from: TrustedBSD Project
src/sys/security/audit:
- Clarify and clean up AUR_ types to match Solaris.
- Clean up use of host vs. network byte order for IP addresses.
- Remove combined user/kernel implementations of some token creation
calls, such as au_to_file(), header calls, etc.
Obtained from: TrustedBSD Project
pointer prototypes from it into their own typedefs. No functional or
ABI change. This allows policies to declare their own function
prototypes based on a common definition from mac_policy.h rather than
duplicating these definitions.
Obtained from: SEDarwin, SPARTA
MFC after: 1 month
subject: ranges of uid, ranges of gid, jail id
objects: ranges of uid, ranges of gid, filesystem,
object is suid, object is sgid, object matches subject uid/gid
object type
We can also negate individual conditions. The ruleset language is
a superset of the previous language, so old rules should continue
to work.
These changes require a change to the API between libugidfw and the
mac_bsdextended module. Add a version number, so we can tell if
we're running mismatched versions.
Update man pages to reflect changes, add extra test cases to
test_ugidfw.c and add a shell script that checks that the the
module seems to do what we expect.
Suggestions from: rwatson, trhodes
Reviewed by: trhodes
MFC after: 2 months
credential: mac_associate_nfsd_label()
This entry point can be utilized by various Mandatory Access Control policies
so they can properly initialize the label of files which get created
as a result of an NFS operation. This work will be useful for fixing kernel
panics associated with accessing un-initialized or invalid vnode labels.
The implementation of these entry points will come shortly.
Obtained from: TrustedBSD
Requested by: mdodd
MFC after: 3 weeks
branch:
Integrate audit.c to audit_worker.c, so as to migrate the worker
thread implementation to its own .c file.
Populate audit_worker.c using parts now removed from audit.c:
- Move audit rotation global variables.
- Move audit_record_write(), audit_worker_rotate(),
audit_worker_drain(), audit_worker(), audit_rotate_vnode().
- Create audit_worker_init() from relevant parts of audit_init(),
which now calls this routine.
- Recreate audit_free(), which wraps uma_zfree() so that
audit_record_zone can be static to audit.c.
- Unstaticize various types and variables relating to the audit
record queue so that audit_worker can get to them. We may want
to wrap these in accessor methods at some point.
- Move AUDIT_PRINTF() to audit_private.h.
Addition of audit_worker.c to kernel configuration, missed in
earlier submit.
Obtained from: TrustedBSD Project
Add ioctls to audit pipes in order to allow querying of the current
record queue state, setting of the queue limit, and querying of pipe
statistics.
Obtained from: TrustedBSD Project
Change send_trigger() prototype to return an int, so that user
space callers can tell if the message was successfully placed
in the trigger queue. This isn't quite the same as it being
successfully received, but is close enough that we can generate
a more useful warning message in audit(8).
Obtained from: TrustedBSD Project
vnode and a mode and checks if a given access mode is permitted.
This centralises the mac_bsdextended_enabled check and the GETATTR
calls and makes the implementation of the mac policy methods simple.
This should make it easier for us to match vnodes on more complex
attributes than just uid and gid in the future, but for now there
should be no functional change.
Approved/Reviewed by: rwatson, trhodes
MFC after: 1 month
- Include audit_internal.h to get definition of internal audit record
structures, as it's no longer in audit.h. Forward declare au_record
in audit_private.h as not all audit_private.h consumers care about
it.
- Remove __APPLE__ compatibility bits that are subsumed by configure
for user space.
- Don't expose in6_addr internals (non-portable, but also cleaner
looking).
- Avoid nested include of audit.h in audit_private.h.
Obtained from: TrustedBSD Project
be called without any vnode locks held. Remove calls to vn_start_write() and
vn_finished_write() in vnode_pager_putpages() and add these calls before the
vnode lock is obtained to most of the callers that don't already have them.
In the future, we may want to acquire the lock early in the function and
hold it across calls to vn_rdwr(), etc, to avoid multiple acquires.
Spotted by: kris (bugmagnet)
Obtained from: TrustedBSD Project
applications to insert a "tee" in the live audit event stream. Records
are inserted into a per-clone queue so that user processes can pull
discreet records out of the queue. Unlike delivery to disk, audit pipes
are "lossy", dropping records in low memory conditions or when the
process falls behind real-time events. This mechanism is appropriate
for use by live monitoring systems, host-based intrusion detection, etc,
and avoids applications having to dig through active on-disk trails that
are owned by the audit daemon.
Obtained from: TrustedBSD Project
initialization routines into a ctor, tear-down to a dtor, cleaning
up, etc. This will allow audit records to be allocated from
per-cpu caches.
On recent FreeBSD, dropping the audit_mtx around freeing to UMA is
no longer required (at one point it was possible to acquire Giant
on that path), so a mutex-free thread-local drain is no longer
required.
Obtained from: TrustedBSD Project
This should not happen, but with this assert, brueffer and I would
not have spent 45 minutes trying to figure out why he wasn't
seeing audit records with the audit version in CVS.
Obtained from: TrustedBSD Project
an incompatible conversion from a 64-bit pointer to a 32-bit integer on
64-bit platforms. We will investigate whether Solaris uses a 64-bit
token here, or a new record here, in order to avoid truncating user
pointers that are 64-bit. However, in the mean time, truncation is fine
as these are rarely/never used fields in audit records.
Obtained from: TrustedBSD Project
- td_ar to struct thread, which holds the in-progress audit record during
a system call.
- p_au to struct proc, which holds per-process audit state, such as the
audit identifier, audit terminal, and process audit masks.
In the earlier implementation, td_ar was added to the zero'd section of
struct thread. In order to facilitate merging to RELENG_6, it has been
moved to the end of the data structure, requiring explicit
initalization in the thread constructor.
Much help from: wsalamon
Obtained from: TrustedBSD Project
- Management of audit state on processes.
- Audit system calls to configure process and system audit state.
- Reliable audit record queue implementation, audit_worker kernel
thread to asynchronously store records on disk.
- Audit event argument.
- Internal audit data structure -> BSM audit trail conversion library.
- Audit event pre-selection.
- Audit pseudo-device permitting kernel->user upcalls to notify auditd
of kernel audit events.
Much work by: wsalamon
Obtained from: TrustedBSD Project, Apple Computer, Inc.
security.mac.biba.interfaces_equal
If non-zero, all network interfaces be created with the label:
biba/equal(equal-equal)
This is useful where programs which initialize network interfaces
do not have any labeling support. This includes dhclient and ppp. A
long term solution is to add labeling support into dhclient(8)
and ppp(8), and remove this variable.
It should be noted that this behavior is different then setting the:
security.mac.biba.trust_all_interfaces
sysctl variable, as this will create interfaces with a biba/high label.
Lower integrity processes are not able to write to the interface in this
event. The security.mac.biba.interfaces_equal will override
trust_all_interfaces.
The security.mac.biba.interfaces_equal variable will be set to zero
or disabled by default.
MFC after: 2 weeks
- Prefer '_' to ' ', as it results in more easily parsed results in
memory monitoring tools such as vmstat.
- Remove punctuation that is incompatible with using memory type names
as file names, such as '/' characters.
- Disambiguate some collisions by adding subsystem prefixes to some
memory types.
- Generally prefer lower case to upper case.
- If the same type is defined in multiple architecture directories,
attempt to use the same name in additional cases.
Not all instances were caught in this change, so more work is required to
finish this conversion. Similar changes are required for UMA zone names.
framework. This makes Giant protection around MAC operations which inter-
act with VFS conditional, based on the MPSAFE status of the file system.
Affected the following syscalls:
o __mac_get_fd
o __mac_get_file
o __mac_get_link
o __mac_set_fd
o __mac_set_file
o __mac_set_link
-Drop Giant all together in __mac_set_proc because the
mac_cred_mmapped_drop_perms_recurse routine no longer requires it.
-Move conditional Giant aquisitions to after label allocation routines.
-Move the conditional release of Giant to before label de-allocation
routines.
Discussed with: rwatson
provided access to the root file system before the start of the
init process. This was used briefly by SEBSD before it knew about
preloading data in the loader, and using that method to gain
access to data earlier results in fewer inconsistencies in the
approach. Policy modules still have access to the root file system
creation event through the mac_create_mount() entry point.
Removed now, and will be removed from RELENG_6, in order to gain
third party policy dependencies on the entry point for the lifetime
of the 6.x branch.
MFC after: 3 days
Submitted by: Chris Vance <Christopher dot Vance at SPARTA dot com>
Sponsored by: SPARTA
entry points that will be inserted over the life-time of the 6.x branch,
including for:
- New struct file labeling (void * already added to struct file), events,
access control checks.
- Additional struct mount access control checks, internalization/
externalization.
- mac_check_cap()
- System call enter/exit check and event.
- Socket and vnode ioctl entry points.
MFC after: 3 days
process that caused the clone event to take place for the device driver
creating the device. This allows cloned device drivers to adapt the
device node based on security aspects of the process, such as the uid,
gid, and MAC label.
- Add a cred reference to struct cdev, so that when a device node is
instantiated as a vnode, the cloning credential can be exposed to
MAC.
- Add make_dev_cred(), a version of make_dev() that additionally
accepts the credential to stick in the struct cdev. Implement it and
make_dev() in terms of a back-end make_dev_credv().
- Add a new event handler, dev_clone_cred, which can be registered to
receive the credential instead of dev_clone, if desired.
- Modify the MAC entry point mac_create_devfs_device() to accept an
optional credential pointer (may be NULL), so that MAC policies can
inspect and act on the label or other elements of the credential
when initializing the skeleton device protections.
- Modify tty_pty.c to register clone_dev_cred and invoke make_dev_cred(),
so that the pty clone credential is exposed to the MAC Framework.
While currently primarily focussed on MAC policies, this change is also
a prerequisite for changes to allow ptys to be instantiated with the UID
of the process looking up the pty. This requires further changes to the
pty driver -- in particular, to immediately recycle pty nodes on last
close so that the credential-related state can be recreated on next
lookup.
Submitted by: Andrew Reisse <andrew.reisse@sparta.com>
Obtained from: TrustedBSD Project
Sponsored by: SPAWAR, SPARTA
MFC after: 1 week
MFC note: Merge to 6.x, but not 5.x for ABI reasons
redundant with respect to existing mbuf copy label routines. Expose
a new mac_copy_mbuf() routine at the top end of the Framework and
use that; use the existing mpo_copy_mbuf_label() routine on the
bottom end.
Obtained from: TrustedBSD Project
Sponsored by: SPARTA, SPAWAR
Approved by: re (scottl)
which is invoked from socket() and socketpair(), permitting MAC
policy modules to control the creation of sockets by domain, type, and
protocol.
Obtained from: TrustedBSD Project
Sponsored by: SPARTA, SPAWAR
Approved by: re (scottl)
Requested by: SCC
