ima: Make it independent from 'integrity' LSM

Make the 'ima' LSM independent from the 'integrity' LSM by introducing IMA
own integrity metadata (ima_iint_cache structure, with IMA-specific fields
from the integrity_iint_cache structure), and by managing it directly from
the 'ima' LSM.

Create ima_iint.c and introduce the same integrity metadata management
functions found in iint.c (renamed with ima_). However, instead of putting
metadata in an rbtree, reserve space from IMA in the inode security blob
for a pointer, and introduce the ima_inode_set_iint()/ima_inode_get_iint()
primitives to store/retrieve that pointer. This improves search time from
logarithmic to constant.

Consequently, don't include the inode pointer as field in the
ima_iint_cache structure, since the association with the inode is clear.
Since the inode field is missing in ima_iint_cache, pass the extra inode
parameter to ima_get_verity_digest().

Prefer storing the pointer instead of the entire ima_iint_cache structure,
to avoid too much memory pressure. Use the same mechanism as before, a
cache named ima_iint_cache (renamed from iint_cache), to quickly allocate
a new ima_iint_cache structure when requested by the IMA policy.

Create the new ima_iint_cache in ima_iintcache_init(),
called by init_ima_lsm(), during the initialization of the 'ima' LSM. And,
register ima_inode_free_security() to free the ima_iint_cache structure, if
exists.

Replace integrity_iint_cache with ima_iint_cache in various places of the
IMA code. Also, replace integrity_inode_get() and integrity_iint_find(),
respectively with ima_inode_get() and ima_iint_find().

Finally, move the remaining IMA-specific flags
to security/integrity/ima/ima.h, since they are now unnecessary in the
common integrity layer.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

ima: detect changes to the backing overlay file

Commit 18b44bc5a672 ("ovl: Always reevaluate the file signature for
IMA") forced signature re-evaulation on every file access.

Instead of always re-evaluating the file's integrity, detect a change
to the backing file, by comparing the cached file metadata with the
backing file's metadata. Verifying just the i_version has not changed
is insufficient. In addition save and compare the i_ino and s_dev
as well.

Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Tested-by: Eric Snowberg <eric.snowberg@oracle.com>
Tested-by: Raul E Rangel <rrangel@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

fsverity: rework fsverity_get_digest() again

Address several issues with the calling convention and documentation of
fsverity_get_digest():

- Make it provide the hash algorithm as either a FS_VERITY_HASH_ALG_*
value or HASH_ALGO_* value, at the caller's choice, rather than only a
HASH_ALGO_* value as it did before. This allows callers to work with
the fsverity native algorithm numbers if they want to. HASH_ALGO_* is
what IMA uses, but other users (e.g. overlayfs) should use
FS_VERITY_HASH_ALG_* to match fsverity-utils and the fsverity UAPI.

- Make it return the digest size so that it doesn't need to be looked up
separately. Use the return value for this, since 0 works nicely for
the "file doesn't have fsverity enabled" case. This also makes it
clear that no other errors are possible.

- Rename the 'digest' parameter to 'raw_digest' and clearly document
that it is only useful in combination with the algorithm ID. This
hopefully clears up a point of confusion.

- Export it to modules, since overlayfs will need it for checking the
fsverity digests of lowerdata files
(https://lore.kernel.org/r/dd294a44e8f401e6b5140029d8355f88748cd8fd.1686565330.git.alexl@redhat.com).

Acked-by: Mimi Zohar <zohar@linux.ibm.com> # for the IMA piece
Link: https://lore.kernel.org/r/20230612190047.59755-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>

IMA: use vfs_getattr_nosec to get the i_version

IMA currently accesses the i_version out of the inode directly when it
does a measurement. This is fine for most simple filesystems, but can be
problematic with more complex setups (e.g. overlayfs).

Make IMA instead call vfs_getattr_nosec to get this info. This allows
the filesystem to determine whether and how to report the i_version, and
should allow IMA to work properly with a broader class of filesystems in
the future.

Reported-and-Tested-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

ima: Introduce MMAP_CHECK_REQPROT hook

Commit 98de59bfe4b2f ("take calculation of final prot in
security_mmap_file() into a helper") caused ima_file_mmap() to receive the
protections requested by the application and not those applied by the
kernel.

After restoring the original MMAP_CHECK behavior, existing attestation
servers might be broken due to not being ready to handle new entries
(previously missing) in the IMA measurement list.

Restore the original correct MMAP_CHECK behavior, instead of keeping the
current buggy one and introducing a new hook with the correct behavior.
Otherwise, there would have been the risk of IMA users not noticing the
problem at all, as they would actively have to update the IMA policy, to
switch to the correct behavior.

Also, introduce the new MMAP_CHECK_REQPROT hook to keep the current
behavior, so that IMA users could easily fix a broken attestation server,
although this approach is discouraged due to potentially missing
measurements.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

ima: fix error handling logic when file measurement failed

Restore the error handling logic so that when file measurement fails,
the respective iint entry is not left with the digest data being
populated with zeroes.

Fixes: 54f03916fb89 ("ima: permit fsverity's file digests in the IMA measurement list")
Cc: stable@vger.kernel.org # 5.19
Signed-off-by: Matt Bobrowski <mattbobrowski@google.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

fs: port xattr to mnt_idmap

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

ima: permit fsverity's file digests in the IMA measurement list

Permit fsverity's file digest (a hash of struct fsverity_descriptor) to
be included in the IMA measurement list, based on the new measurement
policy rule 'digest_type=verity' option.

To differentiate between a regular IMA file hash from an fsverity's
file digest, use the new d-ngv2 format field included in the ima-ngv2
template.

The following policy rule requires fsverity file digests and specifies
the new 'ima-ngv2' template, which contains the new 'd-ngv2' field. The
policy rule may be constrained, for example based on a fsuuid or LSM
label.

measure func=FILE_CHECK digest_type=verity template=ima-ngv2

Acked-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

ima: define ima_max_digest_data struct without a flexible array variable

To support larger hash digests in the 'iint' cache, instead of defining
the 'digest' field as the maximum digest size, the 'digest' field was
defined as a flexible array variable. The "ima_digest_data" struct was
wrapped inside a local structure with the maximum digest size. But
before adding the record to the iint cache, memory for the exact digest
size was dynamically allocated.

The original reason for defining the 'digest' field as a flexible array
variable is still valid for the 'iint' cache use case. Instead of
wrapping the 'ima_digest_data' struct in a local structure define
'ima_max_digest_data' struct.

Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

ima: Fix trivial typos in the comments

There are a few minor typos in the comments. Fix these.

Signed-off-by: Austin Kim <austindh.kim@gmail.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

ima: Use strscpy instead of strlcpy

strlcpy is deprecated, use its safer replacement.

Signed-off-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

IMA: add support to restrict the hash algorithms used for file appraisal

The kernel accepts any hash algorithm as a value for the security.ima
xattr. Users may wish to restrict the accepted algorithms to only
support strong cryptographic ones.

Provide the plumbing to restrict the permitted set of hash algorithms
used for verifying file hashes and signatures stored in security.ima
xattr.

Signed-off-by: THOBY Simon <Simon.THOBY@viveris.fr>
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

ima: handle idmapped mounts

IMA does sometimes access the inode's i_uid and compares it against the
rules' fowner. Enable IMA to handle idmapped mounts by passing down the
mount's user namespace. We simply make use of the helpers we introduced
before. If the initial user namespace is passed nothing changes so
non-idmapped mounts will see identical behavior as before.

Link: https://lore.kernel.org/r/20210121131959.646623-27-christian.brauner@ubuntu.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

IMA: define a hook to measure kernel integrity critical data

IMA provides capabilities to measure file and buffer data. However,
various data structures, policies, and states stored in kernel memory
also impact the integrity of the system. Several kernel subsystems
contain such integrity critical data. These kernel subsystems help
protect the integrity of the system. Currently, IMA does not provide a
generic function for measuring kernel integrity critical data.

Define ima_measure_critical_data, a new IMA hook, to measure kernel
integrity critical data.

Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

IMA: generalize keyring specific measurement constructs

IMA functions such as ima_match_keyring(), process_buffer_measurement(),
ima_match_policy() etc. handle data specific to keyrings. Currently,
these constructs are not generic to handle any func specific data.
This makes it harder to extend them without code duplication.

Refactor the keyring specific measurement constructs to be generic and
reusable in other measurement scenarios.

Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

ima: Support additional conditionals in the KEXEC_CMDLINE hook function

Take the properties of the kexec kernel's inode and the current task
ownership into consideration when matching a KEXEC_CMDLINE operation to
the rules in the IMA policy. This allows for some uniformity when
writing IMA policy rules for KEXEC_KERNEL_CHECK, KEXEC_INITRAMFS_CHECK,
and KEXEC_CMDLINE operations.

Prior to this patch, it was not possible to write a set of rules like
this:

dont_measure func=KEXEC_KERNEL_CHECK obj_type=foo_t
dont_measure func=KEXEC_INITRAMFS_CHECK obj_type=foo_t
dont_measure func=KEXEC_CMDLINE obj_type=foo_t
measure func=KEXEC_KERNEL_CHECK
measure func=KEXEC_INITRAMFS_CHECK
measure func=KEXEC_CMDLINE

The inode information associated with the kernel being loaded by a
kexec_kernel_load(2) syscall can now be included in the decision to
measure or not

Additonally, the uid, euid, and subj_* conditionals can also now be
used in KEXEC_CMDLINE rules. There was no technical reason as to why
those conditionals weren't being considered previously other than
ima_match_rules() didn't have a valid inode to use so it immediately
bailed out for KEXEC_CMDLINE operations rather than going through the
full list of conditional comparisons.

Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: kexec@lists.infradead.org
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

ima: Directly free *entry in ima_alloc_init_template() if digests is NULL

To support multiple template digests, the static array entry->digest has
been replaced with a dynamically allocated array in commit aa724fe18a8a
("ima: Switch to dynamically allocated buffer for template digests"). The
array is allocated in ima_alloc_init_template() and if the returned pointer
is NULL, ima_free_template_entry() is called.

However, (*entry)->template_desc is not yet initialized while it is used by
ima_free_template_entry(). This patch fixes the issue by directly freeing
*entry without calling ima_free_template_entry().

Fixes: aa724fe18a8a ("ima: Switch to dynamically allocated buffer for template digests")
Reported-by: syzbot+223310b454ba6b75974e@syzkaller.appspotmail.com
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

ima: Switch to dynamically allocated buffer for template digests

This patch dynamically allocates the array of tpm_digest structures in
ima_alloc_init_template() and ima_restore_template_data(). The size of the
array is equal to the number of PCR banks plus ima_extra_slots, to make
room for SHA1 and the IMA default hash algorithm, when PCR banks with those
algorithms are not allocated.

Calculating the SHA1 digest is mandatory, as SHA1 still remains the default
hash algorithm for the measurement list. When IMA will support the Crypto
Agile format, remaining digests will be also provided.

The position in the measurement entry array of the SHA1 digest is stored in
the ima_sha1_idx global variable and is determined at IMA initialization
time.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

ima: Store template digest directly in ima_template_entry

In preparation for the patch that calculates a digest for each allocated
PCR bank, this patch passes to ima_calc_field_array_hash() the
ima_template_entry structure, so that digests can be directly stored in
that structure instead of ima_digest_data.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

IMA: Add support to limit measuring keys

Limit measuring keys to those keys being loaded onto a given set of
keyrings only and when the user id (uid) matches if uid is specified
in the policy.

This patch defines a new IMA policy option namely "keyrings=" that
can be used to specify a set of keyrings. If this option is specified
in the policy for "measure func=KEY_CHECK" then only the keys
loaded onto a keyring given in the "keyrings=" option are measured.

If uid is specified in the policy then the key is measured only if
the current user id matches the one specified in the policy.

Added a new parameter namely "keyring" (name of the keyring) to
process_buffer_measurement(). The keyring name is passed to
ima_get_action() to determine the required action.
ima_match_rules() is updated to check keyring in the policy, if
specified, for KEY_CHECK function.

Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

ima: ima_api: Use struct_size() in kzalloc()

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct ima_template_entry {
...
struct ima_field_data template_data[0]; /* template related data */
};

instance = kzalloc(sizeof(struct ima_template_entry) + count * sizeof(struct ima_field_data), GFP_NOFS);

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = kzalloc(struct_size(instance, entry, count), GFP_NOFS);

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

ima: Store the measurement again when appraising a modsig

If the IMA template contains the "modsig" or "d-modsig" field, then the
modsig should be added to the measurement list when the file is appraised.

And that is what normally happens, but if a measurement rule caused a file
containing a modsig to be measured before a different rule causes it to be
appraised, the resulting measurement entry will not contain the modsig
because it is only fetched during appraisal. When the appraisal rule
triggers, it won't store a new measurement containing the modsig because
the file was already measured.

We need to detect that situation and store an additional measurement with
the modsig. This is done by adding an IMA_MEASURE action flag if we read a
modsig and the IMA template contains a modsig field.

Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

ima: Define ima-modsig template

Define new "d-modsig" template field which holds the digest that is
expected to match the one contained in the modsig, and also new "modsig"
template field which holds the appended file signature.

Add a new "ima-modsig" defined template descriptor with the new fields as
well as the ones from the "ima-sig" descriptor.

Change ima_store_measurement() to accept a struct modsig * argument so that
it can be passed along to the templates via struct ima_event_data.

Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

ima: Collect modsig

Obtain the modsig and calculate its corresponding hash in
ima_collect_measurement().

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

IMA: Define a new hook to measure the kexec boot command line arguments

Currently during soft reboot(kexec_file_load) boot command line
arguments are not measured. Define hooks needed to measure kexec
command line arguments during soft reboot(kexec_file_load).

- A new ima hook ima_kexec_cmdline is defined to be called by the
kexec code.
- A new function process_buffer_measurement is defined to measure
the buffer hash into the IMA measurement list.
- A new func policy KEXEC_CMDLINE is defined to control the
measurement.

Signed-off-by: Prakhar Srivastava <prsriva02@gmail.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

IMA: support for per policy rule template formats

Admins may wish to log different measurements using different IMA
templates. Add support for overriding the default template on a per-rule
basis.

Inspired-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Matthew Garrett <mjg59@google.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

ima: Use designated initializers for struct ima_event_data

Designated initializers allow specifying only the members of the struct
that need initialization. Non-mentioned members are initialized to zero.

This makes the code a bit clearer (particularly in ima_add_boot_aggregate)
and also allows adding a new member to the struct without having to update
all struct initializations.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation version 2 of the license

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 315 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

security: audit and remove any unnecessary uses of module.h

Historically a lot of these existed because we did not have
a distinction between what was modular code and what was providing
support to modules via EXPORT_SYMBOL and friends. That changed
when we forked out support for the latter into the export.h file.
This means we should be able to reduce the usage of module.h
in code that is obj-y Makefile or bool Kconfig.

The advantage in removing such instances is that module.h itself
sources about 15 other headers; adding significantly to what we feed
cpp, and it can obscure what headers we are effectively using.

Since module.h might have been the implicit source for init.h
(for __init) and for export.h (for EXPORT_SYMBOL) we consider each
instance for the presence of either and replace as needed.

Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: John Johansen <john.johansen@canonical.com>
Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: linux-security-module@vger.kernel.org
Cc: linux-integrity@vger.kernel.org
Cc: keyrings@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: James Morris <james.morris@microsoft.com>

audit: use current whenever possible

There are many places, notably audit_log_task_info() and
audit_log_exit(), that take task_struct pointers but in reality they
are always working on the current task. This patch eliminates the
task_struct arguments and uses current directly which allows a number
of cleanups as well.

Acked-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

security/integrity: constify some read-only data

Constify some static data that is never modified,
so that it is placed in .rodata.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

audit: use inline function to get audit context

Recognizing that the audit context is an internal audit value, use an
access function to retrieve the audit context pointer for the task
rather than reaching directly into the task struct to get it.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: merge fuzz in auditsc.c and selinuxfs.c, checkpatch.pl fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>

ima: drop vla in ima_audit_measurement()

In keeping with the directive to get rid of VLAs [1], let's drop the VLA
from ima_audit_measurement(). We need to adjust the return type of
ima_audit_measurement, because now this function can fail if an allocation
fails.

[1]: https://lkml.org/lkml/2018/3/7/621

v2: just use audit_log_format instead of doing a second allocation
v3: ignore failures in ima_audit_measurement()

Signed-off-by: Tycho Andersen <tycho@tycho.ws>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

IMA: Support using new creds in appraisal policy

The existing BPRM_CHECK functionality in IMA validates against the
credentials of the existing process, not any new credentials that the
child process may transition to. Add an additional CREDS_CHECK target
and refactor IMA to pass the appropriate creds structure. In
ima_bprm_check(), check with both the existing process credentials and
the credentials that will be committed when the new process is started.
This will not change behaviour unless the system policy is extended to
include CREDS_CHECK targets - BPRM_CHECK will continue to check the same
credentials that it did previously.

After this patch, an IMA policy rule along the lines of:

measure func=CREDS_CHECK subj_type=unconfined_t

will trigger if a process is executed and runs as unconfined_t, ignoring
the context of the parent process. This is in contrast to:

measure func=BPRM_CHECK subj_type=unconfined_t

which will trigger if the process that calls exec() is already executing
in unconfined_t, ignoring the context that the child process executes
into.

Signed-off-by: Matthew Garrett <mjg59@google.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

Changelog:
- initialize ima_creds_status

IMA: switch IMA over to new i_version API

Signed-off-by: Jeff Layton <jlayton@redhat.com>

ima: support new "hash" and "dont_hash" policy actions

The builtin ima_appraise_tcb policy, which is specified on the boot
command line, can be replaced with a custom policy, normally early in
the boot process. Custom policies can be more restrictive in some ways,
like requiring file signatures, but can be less restrictive in other
ways, like not appraising mutable files. With a less restrictive policy
in place, files in the builtin policy might not be hashed and labeled
with a security.ima hash. On reboot, files which should be labeled in
the ima_appraise_tcb are not labeled, possibly preventing the system
from booting properly.

To resolve this problem, this patch extends the existing IMA policy
actions "measure", "dont_measure", "appraise", "dont_appraise", and
"audit" with "hash" and "dont_hash". The new "hash" action will write
the file hash as security.ima, but without requiring the file to be
appraised as well.

For example, the builtin ima_appraise_tcb policy includes the rule,
"appraise fowner=0". Adding the "hash fowner=0" rule to a custom
policy, will cause the needed file hashes to be calculated and written
as security.ima xattrs.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>

ima: always measure and audit files in policy

All files matching a "measure" rule must be included in the IMA
measurement list, even when the file hash cannot be calculated.
Similarly, all files matching an "audit" rule must be audited, even when
the file hash can not be calculated.

The file data hash field contained in the IMA measurement list template
data will contain 0's instead of the actual file hash digest.

Note:
In general, adding, deleting or in anyway changing which files are
included in the IMA measurement list is not a good idea, as it might
result in not being able to unseal trusted keys sealed to a specific
TPM PCR value. This patch not only adds file measurements that were
not previously measured, but specifies that the file hash value for
these files will be 0's.

As the IMA measurement list ordering is not consistent from one boot
to the next, it is unlikely that anyone is sealing keys based on the
IMA measurement list. Remote attestation servers should be able to
process these new measurement records, but might complain about
these unknown records.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Reviewed-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>

ima: allow to check MAY_APPEND

Otherwise some mask and inmask tokens with MAY_APPEND flag may not work
as expected.

Signed-off-by: Lans Zhang <jia.zhang@windriver.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

ima: fix ima_d_path() possible race with rename

On failure to return a pathname from ima_d_path(), a pointer to
dname is returned, which is subsequently used in the IMA measurement
list, the IMA audit records, and other audit logging. Saving the
pointer to dname for later use has the potential to race with rename.

Intead of returning a pointer to dname on failure, this patch returns
a pointer to a copy of the filename.

Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org

ima: change integrity cache to store measured pcr

IMA avoids re-measuring files by storing the current state as a flag in
the integrity cache. It will then skip adding a new measurement log entry
if the cache reports the file as already measured.

If a policy measures an already measured file to a new PCR, the measurement
will not be added to the list. This patch implements a new bitfield for
specifying which PCR the file was measured into, rather than if it was
measured.

Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

ima: include pcr for each measurement log entry

The IMA measurement list entries include the Kconfig defined PCR value.
This patch defines a new ima_template_entry field for including the PCR
as specified in the policy rule.

Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

ima: extend ima_get_action() to return the policy pcr

Different policy rules may extend different PCRs. This patch retrieves
the specific PCR for the matched rule. Subsequent patches will include
the rule specific PCR in the measurement list and extend the appropriate
PCR.

Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

constify ima_d_path()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

ima: define a new hook to measure and appraise a file already in memory

This patch defines a new IMA hook ima_post_read_file() for measuring
and appraising files read by the kernel. The caller loads the file into
memory before calling this function, which calculates the hash followed by
the normal IMA policy based processing.

Changelog v5:
- fail ima_post_read_file() if either file or buf is NULL
v3:
- rename ima_hash_and_process_file() to ima_post_read_file()

v1:
- split patch

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>

ima: use "ima_hooks" enum as function argument

Cleanup the function arguments by using "ima_hooks" enumerator as needed.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Petko Manolov <petkan@mip-labs.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>

ima: separate 'security.ima' reading functionality from collect

Instead of passing pointers to pointers to ima_collect_measurent() to
read and return the 'security.ima' xattr value, this patch moves the
functionality to the calling process_measurement() to directly read
the xattr and pass only the hash algo to the ima_collect_measurement().

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

ima: pass iint to ima_add_violation()

This patch adds the iint associated to the current inode as a new
parameter of ima_add_violation(). The passed iint is always not NULL
if a violation is detected. This modification will be used to determine
the inode for which there is a violation.

Since the 'd' and 'd-ng' template field init() functions were detecting
a violation from the value of the iint pointer, they now check the new
field 'violation', added to the 'ima_event_data' structure.

Changelog:
- v1:
- modified an old comment (Roberto Sassu)

Signed-off-by: Roberto Sassu <rsassu@suse.de>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

ima: wrap event related data to the new ima_event_data structure

All event related data has been wrapped into the new 'ima_event_data'
structure. The main benefit of this patch is that a new information
can be made available to template fields initialization functions
by simply adding a new field to the new structure instead of modifying
the definition of those functions.

Changelog:
- v2:
- f_dentry replaced with f_path.dentry (Roberto Sassu)
- removed declaration of temporary variables in template field functions
when possible (suggested by Dmitry Kasatkin)

Signed-off-by: Roberto Sassu <rsassu@suse.de>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

kill f_dentry uses

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

ima: load x509 certificate from the kernel

Define configuration option to load X509 certificate into the
IMA trusted kernel keyring. It implements ima_load_x509() hook
to load X509 certificate into the .ima trusted kernel keyring
from the root filesystem.

Changes in v3:
* use ima_policy_flag in ima_get_action()
ima_load_x509 temporarily clears ima_policy_flag to disable
appraisal to load key. Use it to skip appraisal rules.
* Key directory path changed to /etc/keys (Mimi)
* Expand IMA_LOAD_X509 Kconfig help

Changes in v2:
* added '__init'
* use ima_policy_flag to disable appraisal to load keys

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

ima: use path names cache

__getname() uses slab allocation which is faster than kmalloc.
Make use of it.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

ima: detect violations for mmaped files

This patch fixes the detection of the 'open_writers' violation for mmaped
files.

before) an 'open_writers' violation is detected if the policy contains
a rule with the criteria: func=FILE_CHECK mask=MAY_READ

after) an 'open_writers' violation is detected if the current event
matches one of the policy rules.

With the old behaviour, the 'open_writers' violation is not detected
in the following case:

policy:
measure func=FILE_MMAP mask=MAY_EXEC

steps:
1) open a shared library for writing
2) execute a binary that links that shared library
3) during the binary execution, modify the shared library and save
the change

result:
the 'open_writers' violation measurement is not present in the IMA list.

Only binaries executed are protected from writes. For libraries mapped
in memory there is the flag MAP_DENYWRITE for this purpose, but according
to the output of 'man mmap', the mmap flag is ignored.

Since ima_rdwr_violation_check() is now called by process_measurement()
the information about if the inode must be measured is already provided
by ima_get_action(). Thus the unnecessary function ima_must_measure()
has been removed.

Changes in v3 (Dmitry Kasatkin):
- Violation for MMAP_CHECK function are verified since this patch
- Changed patch description a bit

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

ima: remove usage of filename parameter

In all cases except ima_bprm_check() the filename was not defined
and ima_d_path() was used to find the full path. Unfortunately,
the bprm filename is a relative pathname (eg. ./<dir>/filename).

ima_bprm_check() selects between bprm->interp and bprm->filename.
The following dump demonstrates the differences between using
filename and interp.

bprm->filename
filename: ./foo.sh, pathname: /root/bin/foo.sh
filename: ./foo.sh, pathname: /bin/dash

bprm->interp
filename: ./foo.sh, pathname: /root/bin/foo.sh
filename: /bin/sh, pathname: /bin/dash

In both cases the pathnames are currently the same. This patch
removes usage of filename and interp in favor of d_absolute_path.

Changes v3:
- 11 extra bytes for "deleted" not needed (Mimi)
- purpose "replace relative bprm filename with full pathname" (Mimi)

Changes v2:
- use d_absolute_path() instead of d_path to work in chroot environments.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

ima: audit log files opened with O_DIRECT flag

Files are measured or appraised based on the IMA policy. When a
file, in policy, is opened with the O_DIRECT flag, a deadlock
occurs.

The first attempt at resolving this lockdep temporarily removed the
O_DIRECT flag and restored it, after calculating the hash. The
second attempt introduced the O_DIRECT_HAVELOCK flag. Based on this
flag, do_blockdev_direct_IO() would skip taking the i_mutex a second
time. The third attempt, by Dmitry Kasatkin, resolves the i_mutex
locking issue, by re-introducing the IMA mutex, but uncovered
another problem. Reading a file with O_DIRECT flag set, writes
directly to userspace pages. A second patch allocates a user-space
like memory. This works for all IMA hooks, except ima_file_free(),
which is called on __fput() to recalculate the file hash.

Until this last issue is addressed, do not 'collect' the
measurement for measuring, appraising, or auditing files opened
with the O_DIRECT flag set. Based on policy, permit or deny file
access. This patch defines a new IMA policy rule option named
'permit_directio'. Policy rules could be defined, based on LSM
or other criteria, to permit specific applications to open files
with the O_DIRECT flag set.

Changelog v1:
- permit or deny file access based IMA policy rules

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Cc: <stable@vger.kernel.org>

ima: return d_name.name if d_path fails

This is a small refactoring so ima_d_path() returns dentry name
if path reconstruction fails. It simplifies callers actions
and removes code duplication.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

integrity: fix checkpatch errors

Between checkpatch changes (eg. sizeof) and inconsistencies between
Lindent and checkpatch, unfixed checkpatch errors make it difficult
to see new errors. This patch fixes them. Some lines with over 80 chars
remained unchanged to improve code readability.

The "extern" keyword is removed from internal evm.h to make it consistent
with internal ima.h.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

ima: use static const char array definitions

A const char pointer allocates memory for a pointer as well as for
a string, This patch replaces a number of the const char pointers
throughout IMA, with a static const char array.

Suggested-by: David Howells <dhowells@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>

ima: new helper: file_inode(file)

Replace "file->f_dentry->d_inode" with the new file_inode() helper
function.

Signed-off-by: Libo Chen <clbchenlibo.chen@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

ima: properly free ima_template_entry structures

The new templates management mechanism records information associated
to an event into an array of 'ima_field_data' structures and makes it
available through the 'template_data' field of the 'ima_template_entry'
structure (the element of the measurements list created by IMA).

Since 'ima_field_data' contains dynamically allocated data (which length
varies depending on the data associated to a selected template field),
it is not enough to just free the memory reserved for a
'ima_template_entry' structure if something goes wrong.

This patch creates the new function ima_free_template_entry() which
walks the array of 'ima_field_data' structures, frees the memory
referenced by the 'data' pointer and finally the space reserved for
the 'ima_template_entry' structure. Further, it replaces existing kfree()
that have a pointer to an 'ima_template_entry' structure as argument
with calls to the new function.

Fixes: a71dc65: ima: switch to new template management mechanism
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>

ima: do not include field length in template digest calc for ima template

To maintain compatibility with userspace tools, the field length must not
be included in the template digest calculation for the 'ima' template.

Fixes commit: a71dc65 ima: switch to new template management mechanism

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

ima: extend the measurement list to include the file signature

This patch defines a new template called 'ima-sig', which includes
the file signature in the template data, in addition to the file's
digest and pathname.

A template is composed of a set of fields. Associated with each
field is an initialization and display function. This patch defines
a new template field called 'sig', the initialization function
ima_eventsig_init(), and the display function ima_show_template_sig().

This patch modifies the .field_init() function definition to include
the 'security.ima' extended attribute and length.

Changelog:
- remove unused code (Dmitry Kasatkin)
- avoid calling ima_write_template_field_data() unnecesarily (Roberto Sassu)
- rename DATA_FMT_SIG to DATA_FMT_HEX
- cleanup ima_eventsig_init() based on Roberto's comments

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>

ima: add audit log support for larger hashes

Different files might be signed based on different hash algorithms.
This patch prefixes the audit log measurement hash with the hash
algorithm.

Changelog:
- use generic HASH_ALGO defintions
- use ':' as delimiter between the hash algorithm and the digest
(Roberto Sassu)
- always include the hash algorithm used when audit-logging a measurement

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Peter Moody <pmoody@google.com>

ima: switch to new template management mechanism

This patch performs the switch to the new template mechanism by modifying
the functions ima_alloc_init_template(), ima_measurements_show() and
ima_ascii_measurements_show(). The old function ima_template_show() was
removed as it is no longer needed. Also, if the template descriptor used
to generate a measurement entry is not 'ima', the whole length of field
data stored for an entry is provided before the data itself through the
binary_runtime_measurement interface.

Changelog:
- unnecessary to use strncmp() (Mimi Zohar)
- create new variable 'field' in ima_alloc_init_template() (Roberto Sassu)
- use GFP_NOFS flag in ima_alloc_init_template() (Roberto Sassu)
- new variable 'num_fields' in ima_store_template() (Roberto Sassu,
proposed by Mimi Zohar)
- rename ima_calc_buffer_hash/template_hash() to ima_calc_field_array_hash(),
something more generic (Mimi, requested by Dmitry)
- sparse error fix - Fengguang Wu
- fix lindent warnings
- always include the field length in the template data length
- include the template field length variable size in the template data length
- include both the template field data and field length in the template digest
calculation. Simplifies verifying the template digest. (Mimi)

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

ima: define new function ima_alloc_init_template() to API

Instead of allocating and initializing the template entry from multiple
places (eg. boot aggregate, violation, and regular measurements), this
patch defines a new function called ima_alloc_init_template(). The new
function allocates and initializes the measurement entry with the inode
digest and the filename.

In respect to the current behavior, it truncates the file name passed
in the 'filename' argument if the latter's size is greater than 255 bytes
and the passed file descriptor is NULL.

Changelog:
- initialize 'hash' variable for non TPM case - Mimi
- conform to expectation for 'iint' to be defined as a pointer. - Mimi
- add missing 'file' dependency for recalculating file hash. - Mimi

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

ima: pass the filename argument up to ima_add_template_entry()

Pass the filename argument to ima_add_template_entry() in order to
eliminate a dependency on template specific data (third argument of
integrity_audit_msg).

This change is required because, with the new template management
mechanism, the generation of a new measurement entry will be performed
by new specific functions (introduced in next patches) and the current IMA
code will not be aware anymore of how data is stored in the entry payload.

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

ima: pass the file descriptor to ima_add_violation()

Pass the file descriptor instead of the inode to ima_add_violation(),
to make the latter consistent with ima_store_measurement() in
preparation for the new template architecture.

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

ima: support arbitrary hash algorithms in ima_calc_buffer_hash

ima_calc_buffer_hash will be used with different hash algorithms.
This patch provides support for arbitrary hash algorithms in
ima_calc_buffer_hash.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

ima: differentiate between template hash and file data hash sizes

The TPM v1.2 limits the template hash size to 20 bytes. This
patch differentiates between the template hash size, as defined
in the ima_template_entry, and the file data hash size, as
defined in the ima_template_data. Subsequent patches add support
for different file data hash algorithms.

Change log:
- hash digest definition in ima_store_template() should be TPM_DIGEST_SIZE

Signed-off-by: Mimi Zohar <zohar@us.ibm.com>

ima: use dynamically allocated hash storage

For each inode in the IMA policy, an iint is allocated. To support
larger hash digests, the iint digest size changed from 20 bytes to
the maximum supported hash digest size. Instead of allocating the
maximum size, which most likely is not needed, this patch dynamically
allocates the needed hash storage.

Changelog:
- fix krealloc bug

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

ima: read and use signature hash algorithm

All files on the filesystem, currently, are hashed using the same hash
algorithm. In preparation for files from different packages being
signed using different hash algorithms, this patch adds support for
reading the signature hash algorithm from the 'security.ima' extended
attribute and calculates the appropriate file data hash based on it.

Changelog:
- fix scripts Lindent and checkpatch msgs - Mimi
- fix md5 support for older version, which occupied 20 bytes in the
xattr, not the expected 16 bytes. Fix the comparison to compare
only the first 16 bytes.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

ima: provide support for arbitrary hash algorithms

In preparation of supporting more hash algorithms with larger hash sizes
needed for signature verification, this patch replaces the 20 byte sized
digest, with a more flexible structure. The new structure includes the
hash algorithm, digest size, and digest.

Changelog:
- recalculate filedata hash for the measurement list, if the signature
hash digest size is greater than 20 bytes.
- use generic HASH_ALGO_
- make ima_calc_file_hash static
- scripts lindent and checkpatch fixes

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

new helper: file_inode(file)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

ima: rename hash calculation functions

Rename hash calculation functions to reflect meaning
and change argument order in conventional way.

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

ima: move full pathname resolution to separate function

Define a new function ima_d_path(), which returns the full pathname.
This function will be used further, for example, by the directory
verification code.

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

ima: rename FILE_MMAP to MMAP_CHECK

Rename FILE_MMAP hook to MMAP_CHECK to be consistent with the other
hook names.

Signed-off-by: Mimi Zohar <zohar@us.ibm.com>

ima: support new kernel module syscall

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: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

ima: audit log hashes

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: Peter Moody <pmoody@google.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

ima: rename ima_must_appraise_or_measure

When AUDIT action support is added to the IMA,
ima_must_appraise_or_measure() does not reflect the real meaning anymore.
Rename it to ima_get_action().

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

ima: add support for different security.ima data types

IMA-appraisal currently verifies the integrity of a file based on a
known 'good' measurement value. This patch reserves the first byte
of 'security.ima' as a place holder for the type of method used for
verifying file data integrity.

Changelog v1:
- Use the newly defined 'struct evm_ima_xattr_data'

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@nokia.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

ima: integrity appraisal extension

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: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>

ima: use full pathnames in measurement list

The IMA measurement list contains filename hints, which can be
ambigious without the full pathname. This patch replaces the
filename hint with the full pathname, simplifying for userspace
the correlating of file hash measurements with files.

Change log v1:
- Revert to short filenames, when full pathname is longer than IMA
measurement buffer size. (Based on Dmitry's review)

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

ima: free duplicate measurement memory

Info about new measurements are cached in the iint for performance. When
the inode is flushed from cache, the associated iint is flushed as well.
Subsequent access to the inode will cause the inode to be re-measured and
will attempt to add a duplicate entry to the measurement list.

This patch frees the duplicate measurement memory, fixing a memory leak.

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Cc: stable@vger.kernel.org

integrity: move ima inode integrity data management

Move the inode integrity data(iint) management up to the integrity directory
in order to share the iint among the different integrity models.

Changelog:
- don't define MAX_DIGEST_SIZE
- rename several globally visible 'ima_' prefixed functions, structs,
locks, etc to 'integrity_'
- replace '20' with SHA1_DIGEST_SIZE
- reflect location change in appropriate Kconfig and Makefiles
- remove unnecessary initialization of iint_initialized to 0
- rebased on current ima_iint.c
- define integrity_iint_store/lock as static

There should be no other functional changes.

Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com>

ima: remove unnecessary call to ima_must_measure

The original ima_must_measure() function based its results on cached
iint information, which required an iint be allocated for all files.
Currently, an iint is allocated only for files in policy. As a result,
for those files in policy, ima_must_measure() is now called twice: once
to determine if the inode is in the measurement policy and, the second
time, to determine if it needs to be measured/re-measured.

The second call to ima_must_measure() unnecessarily checks to see if
the file is in policy. As we already know the file is in policy, this
patch removes the second unnecessary call to ima_must_measure(), removes
the vestige iint parameter, and just checks the iint directly to determine
if the inode has been measured or needs to be measured/re-measured.

Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Eric Paris <eparis@redhat.com>

IMA: move read counter into struct inode

IMA currently allocated an inode integrity structure for every inode in
core. This stucture is about 120 bytes long. Most files however
(especially on a system which doesn't make use of IMA) will never need
any of this space. The problem is that if IMA is enabled we need to
know information about the number of readers and the number of writers
for every inode on the box. At the moment we collect that information
in the per inode iint structure and waste the rest of the space. This
patch moves those counters into the struct inode so we can eventually
stop allocating an IMA integrity structure except when absolutely
needed.

This patch does the minimum needed to move the location of the data.
Further cleanups, especially the location of counter updates, may still
be possible.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.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: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

ima: rename PATH_CHECK to FILE_CHECK

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: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

integrity: audit update

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: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

integrity: IMA as an integrity service provider

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: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>