With the addition of the new kernel module syscall, which defines two
arguments - a file descriptor to the kernel module and a pointer to a NULL
terminated string of module arguments - it is now possible to measure and
appraise kernel modules like any other file on the file system.

This patch adds support to measure and appraise kernel modules in an
extensible and consistent manner.

To support filesystems without extended attribute support, additional
patches could pass the signature as the first parameter.
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Use kuid's in the IMA rules.

When reporting the current uid in audit logs use from_kuid
to get a usable value.

Cc: Mimi Zohar <zohar@us.ibm.com>
Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>

This adds an 'audit' policy action which audit logs file measurements.

Changelog v6:
 - use new action flag handling (Dmitry Kasatkin).
 - removed whitespace (Mimi)

Changelog v5:
 - use audit_log_untrustedstring.

Changelog v4:
 - cleanup digest -> hash conversion.
 - use filename rather than d_path in ima_audit_measurement.

Changelog v3:
 - Use newly exported audit_log_task_info for logging pid/ppid/uid/etc.
 - Update the ima_policy ABI documentation.

Changelog v2:
 - Use 'audit' action rather than 'measure_and_audit' to permit
 auditing in the absence of measuring..

Changelog v1:
 - Initial posting.
Signed-off-by: NPeter Moody <pmoody@google.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

Make the IMA action flag handling generic in order to support
additional new actions, without requiring changes to the base
implementation.  New actions, like audit logging, will only
need to modify the define statements.
Signed-off-by: NDmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

Unlike the IMA measurement policy, the appraise policy can not be dependent
on runtime process information, such as the task uid, as the 'security.ima'
xattr is written on file close and must be updated each time the file changes,
regardless of the current task uid.

This patch extends the policy language with 'fowner', defines an appraise
policy, which appraises all files owned by root, and defines 'ima_appraise_tcb',
a new boot command line option, to enable the appraise policy.

Changelog v3:
- separate the measure from the appraise rules in order to support measuring
  without appraising and appraising without measuring.
- change appraisal default for filesystems without xattr support to fail
- update default appraise policy for cgroups

Changelog v1:
- don't appraise RAMFS (Dmitry Kasatkin)
- merged rest of "ima: ima_must_appraise_or_measure API change" commit
  (Dmtiry Kasatkin)

  ima_must_appraise_or_measure() called ima_match_policy twice, which
  searched the policy for a matching rule.  Once for a matching measurement
  rule and subsequently for an appraisal rule. Searching the policy twice
  is unnecessary overhead, which could be noticeable with a large policy.

  The new version of ima_must_appraise_or_measure() does everything in a
  single iteration using a new version of ima_match_policy().  It returns
  IMA_MEASURE, IMA_APPRAISE mask.

  With the use of action mask only one efficient matching function
  is enough.  Removed other specific versions of matching functions.

Changelog:
- change 'owner' to 'fowner' to conform to the new LSM conditions posted by
  Roberto Sassu.
- fix calls to ima_log_string()
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NDmitry Kasatkin <dmitry.kasatkin@intel.com>

IMA currently maintains an integrity measurement list used to assert the
integrity of the running system to a third party.  The IMA-appraisal
extension adds local integrity validation and enforcement of the
measurement against a "good" value stored as an extended attribute
'security.ima'.  The initial methods for validating 'security.ima' are
hashed based, which provides file data integrity, and digital signature
based, which in addition to providing file data integrity, provides
authenticity.

This patch creates and maintains the 'security.ima' xattr, containing
the file data hash measurement.  Protection of the xattr is provided by
EVM, if enabled and configured.

Based on policy, IMA calls evm_verifyxattr() to verify a file's metadata
integrity and, assuming success, compares the file's current hash value
with the one stored as an extended attribute in 'security.ima'.

Changelov v4:
- changed iint cache flags to hex values

Changelog v3:
- change appraisal default for filesystems without xattr support to fail

Changelog v2:
- fix audit msg 'res' value
- removed unused 'ima_appraise=' values

Changelog v1:
- removed unused iint mutex (Dmitry Kasatkin)
- setattr hook must not reset appraised (Dmitry Kasatkin)
- evm_verifyxattr() now differentiates between no 'security.evm' xattr
  (INTEGRITY_NOLABEL) and no EVM 'protected' xattrs included in the
  'security.evm' (INTEGRITY_NOXATTRS).
- replace hash_status with ima_status (Dmitry Kasatkin)
- re-initialize slab element ima_status on free (Dmitry Kasatkin)
- include 'security.ima' in EVM if CONFIG_IMA_APPRAISE, not CONFIG_IMA
- merged half "ima: ima_must_appraise_or_measure API change" (Dmitry Kasatkin)
- removed unnecessary error variable in process_measurement() (Dmitry Kasatkin)
- use ima_inode_post_setattr() stub function, if IMA_APPRAISE not configured
  (moved ima_inode_post_setattr() to ima_appraise.c)
- make sure ima_collect_measurement() can read file

Changelog:
- add 'iint' to evm_verifyxattr() call (Dimitry Kasatkin)
- fix the race condition between chmod, which takes the i_mutex and then
  iint->mutex, and ima_file_free() and process_measurement(), which take
  the locks in the reverse order, by eliminating iint->mutex. (Dmitry Kasatkin)
- cleanup of ima_appraise_measurement() (Dmitry Kasatkin)
- changes as a result of the iint not allocated for all regular files, but
  only for those measured/appraised.
- don't try to appraise new/empty files
- expanded ima_appraisal description in ima/Kconfig
- IMA appraise definitions required even if IMA_APPRAISE not enabled
- add return value to ima_must_appraise() stub
- unconditionally set status = INTEGRITY_PASS *after* testing status,
  not before.  (Found by Joe Perches)
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NDmitry Kasatkin <dmitry.kasatkin@intel.com>

Exclude DEVPTS and BINFMT filesystems from the measurement policy.
Signed-off-by: NDmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

The audit res field ususally indicates success with a 1 and 0 for a
failure.  So make IMA do it the same way.
Signed-off-by: NEric Paris <eparis@redhat.com>
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Don't measure ramfs files.
Signed-off-by: NDmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>

Fix ima_policy.c sparse "warning: dereference of noderef expression"
message, by accessing cred->uid using current_cred().

Changelog v1:
- Change __cred to just cred (based on David Howell's comment)
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

If security_filter_rule_init() doesn't return a rule, then not everything
is as fine as the return code implies.

This bug only occurs when the LSM (eg. SELinux) is disabled at runtime.

Adding an empty LSM rule causes ima_match_rules() to always succeed,
ignoring any remaining rules.

 default IMA TCB policy:
  # PROC_SUPER_MAGIC
  dont_measure fsmagic=0x9fa0
  # SYSFS_MAGIC
  dont_measure fsmagic=0x62656572
  # DEBUGFS_MAGIC
  dont_measure fsmagic=0x64626720
  # TMPFS_MAGIC
  dont_measure fsmagic=0x01021994
  # SECURITYFS_MAGIC
  dont_measure fsmagic=0x73636673

  < LSM specific rule >
  dont_measure obj_type=var_log_t

  measure func=BPRM_CHECK
  measure func=FILE_MMAP mask=MAY_EXEC
  measure func=FILE_CHECK mask=MAY_READ uid=0

Thus without the patch, with the boot parameters 'tcb selinux=0', adding
the above 'dont_measure obj_type=var_log_t' rule to the default IMA TCB
measurement policy, would result in nothing being measured.  The patch
prevents the default TCB policy from being replaced.
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Cc: James Morris <jmorris@namei.org>
Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
Cc: David Safford <safford@watson.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Convert all of the places IMA calls audit_log_format with %s into
audit_log_untrusted_string().  This is going to cause them all to get
quoted, but it should make audit log injection harder.
Signed-off-by: NEric Paris <eparis@redhat.com>
Acked-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

IMA policy load parser will reject any policies with a comment.  This patch
will allow the parser to just ignore lines which start with a #.  This is not
very robust.  # can ONLY be used at the very beginning of a line.  Inline
comments are not allowed.

Signed-off-by: Eric Paris
Acked-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

IMA parser will fail if whitespace is used in any way other than a single
space.  Using a tab or even using 2 spaces in a row will result in a policy
being rejected.  This patch makes the kernel ignore whitespace a bit better.
Signed-off-by: NEric Paris <eparis@redhat.com>
Acked-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Currently the ima policy load code will print what it doesn't understand
but really I think it should reject any policy it doesn't understand.  This
patch makes it so!
Signed-off-by: NEric Paris <eparis@redhat.com>
Acked-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

ima_parse_rule currently sets entry->action = -1 and then later tests
if (entry->action == UNKNOWN).  It is true that UNKNOWN == -1 but actually
setting it to UNKNOWN makes a lot more sense in case things change in the
future.
Signed-off-by: NEric Paris <eparis@redhat.com>
Acked-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

IMA will accept rules which specify things twice and will only pay
attention to the last one.  We should reject such rules.
Signed-off-by: NEric Paris <eparis@redhat.com>
Acked-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Currently IMA will only accept one rule per write().  This patch allows IMA to
accept writes which contain multiple rules but only processes one rule per
write.  \n is used as the delimiter between rules.  IMA will return a short
write indicating that it only accepted up to the first \n.

This allows simple userspace utilities like cat to be used to load an IMA
policy instead of needing a special userspace utility that understood 'one
write per rule'
Signed-off-by: NEric Paris <eparis@redhat.com>
Acked-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: NTejun Heo <tj@kernel.org>
Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

With the movement of the ima hooks functions were renamed from *path* to
*file* since they always deal with struct file.  This patch renames some of
the ima internal flags to make them consistent with the rest of the code.
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: NEric Paris <eparis@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

A number of IMA functions only used during init are not marked with __init.
Add those notations so they are freed automatically.
Signed-off-by: NEric Paris <eparis@redhat.com>
Acked-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

The IMA TCB policy is dangerous.  A normal use can use all of a system's
memory (which cannot be freed) simply by building and running lots of
executables.  The TCB policy is also nearly useless because logging in as root
often causes a policy violation when dealing with utmp, thus rendering the
measurements meaningless.

There is no good fix for this in the kernel.  A full TCB policy would need to
be loaded in userspace using LSM rule matching to get both a protected and
useful system.  But, if too little is measured before userspace can load a real
policy one again ends up with a meaningless set of measurements.  One option
would be to put the policy load inside the initrd in order to get it early
enough in the boot sequence to be useful, but this runs into trouble with the
LSM.  For IMA to measure the LSM policy and the LSM policy loading mechanism
it needs rules to do so, but we already talked about problems with defaulting
to such broad rules....

IMA also depends on the files being measured to be on an FS which implements
and supports i_version.  Since the only FS with this support (ext4) doesn't
even use it by default it seems silly to have any IMA rules by default.

This should reduce the performance overhead of IMA to near 0 while still
letting users who choose to configure their machine as such to inclue the
ima_tcb kernel paramenter and get measurements during boot before they can
load a customized, reasonable policy in userspace.
Signed-off-by: NEric Paris <eparis@redhat.com>
Acked-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

The selinuxfs superblock magic is used inside the IMA code, but is being
defined in two places and could someday get out of sync.  This patch moves the
declaration into magic.h so it is only done once.
Signed-off-by: NEric Paris <eparis@redhat.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

The IMA default policy measures every single file opened by root.  This is
terrible for most users.  Consider a system (like mine) with virtual machine
images.  When those images are touched (which happens at boot for me) those
images are measured.  This is just way too much for the default case.
Signed-off-by: NEric Paris <eparis@redhat.com>
Acked-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

An audit subsystem change replaced AUDIT_EQUAL with Audit_equal.
Update calls to security_filter_rule_init()/match() to reflect
the change.
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Based on discussions on linux-audit, as per Steve Grubb's request
http://lkml.org/lkml/2009/2/6/269, the following changes were made:
- forced audit result to be either 0 or 1.
- made template names const
- Added new stand-alone message type: AUDIT_INTEGRITY_RULE
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Acked-by: NSteve Grubb <sgrubb@redhat.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Fix ima_delete_rules() definition so sparse doesn't complain.
Signed-off-by: NJames Morris <jmorris@namei.org>

Support for a user loadable policy through securityfs
with support for LSM specific policy data.
- free invalid rule in ima_parse_add_rule()
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

IMA provides hardware (TPM) based measurement and attestation for
file measurements. As the Trusted Computing (TPM) model requires,
IMA measures all files before they are accessed in any way (on the
integrity_bprm_check, integrity_path_check and integrity_file_mmap
hooks), and commits the measurements to the TPM. Once added to the
TPM, measurements can not be removed.

In addition, IMA maintains a list of these file measurements, which
can be used to validate the aggregate value stored in the TPM.  The
TPM can sign these measurements, and thus the system can prove, to
itself and to a third party, the system's integrity in a way that
cannot be circumvented by malicious or compromised software.

- alloc ima_template_entry before calling ima_store_template()
- log ima_add_boot_aggregate() failure
- removed unused IMA_TEMPLATE_NAME_LEN
- replaced hard coded string length with #define name
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>