This option creates IMA MOK and blacklist keyrings.  IMA MOK is an
intermediate keyring that sits between .system and .ima keyrings,
effectively forming a simple CA hierarchy.  To successfully import a key
into .ima_mok it must be signed by a key which CA is in .system keyring.
On turn any key that needs to go in .ima keyring must be signed by CA in
either .system or .ima_mok keyrings. IMA MOK is empty at kernel boot.

IMA blacklist keyring contains all revoked IMA keys.  It is consulted
before any other keyring.  If the search is successful the requested
operation is rejected and error is returned to the caller.
Signed-off-by: NPetko Manolov <petkan@mip-labs.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

The new rules get appended to the original policy, forming a queue.
The new rules are first added to a temporary list, which on error
get released without disturbing the normal IMA operations.  On
success both lists (the current policy and the new rules) are spliced.

IMA policy reads are many orders of magnitude more numerous compared to
writes, the match code is RCU protected.  The updater side also does
list splice in RCU manner.
Signed-off-by: NPetko Manolov <petkan@mip-labs.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

The newly added EVM_LOAD_X509 code can be configured even if
CONFIG_EVM is disabled, but that causes a link error:

security/built-in.o: In function `integrity_load_keys':
digsig_asymmetric.c:(.init.text+0x400): undefined reference to `evm_load_x509'

This adds a Kconfig dependency to ensure it is only enabled when
CONFIG_EVM is set as well.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Fixes: 2ce523eb ("evm: load x509 certificate from the kernel")
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

The EVM verification status is cached in iint->evm_status and if it
was successful, never re-verified again when IMA passes the 'iint' to
evm_verifyxattr().

When file attributes or extended attributes change, we may wish to
re-verify EVM integrity as well.  For example, after setting a digital
signature we may need to re-verify the signature and update the
iint->flags that there is an EVM signature.

This patch enables that by resetting evm_status to INTEGRITY_UKNOWN
state.

Changes in v2:
* Flag setting moved to EVM layer
Signed-off-by: NDmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

A crypto HW kernel module can possibly initialize the EVM key from the
kernel __init code to enable EVM before calling the 'init' process.
This patch provides a function evm_set_key() to set the EVM key
directly without using the KEY subsystem.

Changes in v4:
* kernel-doc style for evm_set_key

Changes in v3:
* error reporting moved to evm_set_key
* EVM_INIT_HMAC moved to evm_set_key
* added bitop to prevent key setting race

Changes in v2:
* use size_t for key size instead of signed int
* provide EVM_MAX_KEY_SIZE macro in <linux/evm.h>
* provide EVM_MIN_KEY_SIZE macro in <linux/evm.h>
Signed-off-by: NDmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

In order to enable EVM before starting the 'init' process,
evm_initialized needs to be non-zero.  Previously non-zero indicated
that the HMAC key was loaded.  When EVM loads the X509 before calling
'init', with this patch it is now possible to enable EVM to start
signature based verification.

This patch defines bits to enable EVM if a key of any type is loaded.

Changes in v3:
* print error message if key is not set

Changes in v2:
* EVM_STATE_KEY_SET replaced by EVM_INIT_HMAC
* EVM_STATE_X509_SET replaced by EVM_INIT_X509
Signed-off-by: NDmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

This patch defines a configuration option and the evm_load_x509() hook
to load an X509 certificate onto the EVM trusted kernel keyring.

Changes in v4:
* Patch description updated

Changes in v3:
* Removed EVM_X509_PATH definition. CONFIG_EVM_X509_PATH is used
  directly.

Changes in v2:
* default key patch changed to /etc/keys
Signed-off-by: NDmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

Require all keys added to the EVM keyring be signed by an
existing trusted key on the system trusted keyring.

This patch also switches IMA to use integrity_init_keyring().

Changes in v3:
* Added 'init_keyring' config based variable to skip initializing
  keyring instead of using  __integrity_init_keyring() wrapper.
* Added dependency back to CONFIG_IMA_TRUSTED_KEYRING

Changes in v2:
* Replace CONFIG_EVM_TRUSTED_KEYRING with IMA and EVM common
  CONFIG_INTEGRITY_TRUSTED_KEYRING configuration option
* Deprecate CONFIG_IMA_TRUSTED_KEYRING but keep it for config
  file compatibility. (Mimi Zohar)
Signed-off-by: NDmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

__GFP_WAIT was used to signal that the caller was in atomic context and
could not sleep.  Now it is possible to distinguish between true atomic
context and callers that are not willing to sleep.  The latter should
clear __GFP_DIRECT_RECLAIM so kswapd will still wake.  As clearing
__GFP_WAIT behaves differently, there is a risk that people will clear the
wrong flags.  This patch renames __GFP_WAIT to __GFP_RECLAIM to clearly
indicate what it does -- setting it allows all reclaim activity, clearing
them prevents it.

[akpm@linux-foundation.org: fix build]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NMel Gorman <mgorman@techsingularity.net>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Merge the type-specific data with the payload data into one four-word chunk
as it seems pointless to keep them separate.

Use user_key_payload() for accessing the payloads of overloaded
user-defined keys.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
cc: linux-cifs@vger.kernel.org
cc: ecryptfs@vger.kernel.org
cc: linux-ext4@vger.kernel.org
cc: linux-f2fs-devel@lists.sourceforge.net
cc: linux-nfs@vger.kernel.org
cc: ceph-devel@vger.kernel.org
cc: linux-ima-devel@lists.sourceforge.net

If IMA_LOAD_X509 is enabled, either directly or indirectly via
IMA_APPRAISE_SIGNED_INIT, certificates are loaded onto the IMA
trusted keyring by the kernel via key_create_or_update(). When
the KEY_ALLOC_TRUSTED flag is provided, certificates are loaded
without first verifying the certificate is properly signed by a
trusted key on the system keyring.  This patch removes the
KEY_ALLOC_TRUSTED flag.
Signed-off-by: NDmitry Kasatkin <dmitry.kasatkin@huawei.com>
Cc:  <stable@vger.kernel.org> # 3.19+
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

This patch defines a builtin measurement policy "tcb", similar to the
existing "ima_tcb", but with additional rules to also measure files
based on the effective uid and to measure files opened with the "read"
mode bit set (eg. read, read-write).

Changing the builtin "ima_tcb" policy could potentially break existing
users.  Instead of defining a new separate boot command line option each
time the builtin measurement policy is modified, this patch defines a
single generic boot command line option "ima_policy=" to specify the
builtin policy and deprecates the use of the builtin ima_tcb policy.

[The "ima_policy=" boot command line option is based on Roberto Sassu's
"ima: added new policy type exec" patch.]
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: NDr. Greg Wettstein <gw@idfusion.org>
Cc: stable@vger.kernel.org

The current "mask" policy option matches files opened as MAY_READ,
MAY_WRITE, MAY_APPEND or MAY_EXEC.  This patch extends the "mask"
option to match files opened containing one of these modes.  For
example, "mask=^MAY_READ" would match files opened read-write.
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: NDr. Greg Wettstein <gw@idfusion.org>
Cc: stable@vger.kernel.org

The new "euid" policy condition measures files with the specified
effective uid (euid).  In addition, for CAP_SETUID files it measures
files with the specified uid or suid.

Changelog:
- fixed checkpatch.pl warnings
- fixed avc denied {setuid} messages - based on Roberto's feedback
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: NDr. Greg Wettstein <gw@idfusion.org>
Cc: stable@vger.kernel.org

This patch fixes a bug introduced in "4d7aeee7 ima: define new template
ima-ng and template fields d-ng and n-ng".

Changelog:
- change int to uint32 (Roberto Sassu's suggestion)
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: NRoberto Sassu <rsassu@suse.de>
Cc: stable@vger.kernel.org # 3.13

Most code already uses consts for the struct kernel_param_ops,
sweep the kernel for the last offending stragglers. Other than
include/linux/moduleparam.h and kernel/params.c all other changes
were generated with the following Coccinelle SmPL patch. Merge
conflicts between trees can be handled with Coccinelle.

In the future git could get Coccinelle merge support to deal with
patch --> fail --> grammar --> Coccinelle --> new patch conflicts
automatically for us on patches where the grammar is available and
the patch is of high confidence. Consider this a feature request.

Test compiled on x86_64 against:

	* allnoconfig
	* allmodconfig
	* allyesconfig

@ const_found @
identifier ops;
@@

const struct kernel_param_ops ops = {
};

@ const_not_found depends on !const_found @
identifier ops;
@@

-struct kernel_param_ops ops = {
+const struct kernel_param_ops ops = {
};

Generated-by: Coccinelle SmPL
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Junio C Hamano <gitster@pobox.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: cocci@systeme.lip6.fr
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NLuis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

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

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

This patch adds validity checks for 'path' parameter and
makes it const.
Signed-off-by: NDmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

EVM needs to be atomically updated when removing xattrs.
Otherwise concurrent EVM verification may fail in between.
This patch fixes by moving i_mutex unlocking after calling
EVM hook. fsnotify_xattr() is also now called while locked
the same way as it is done in __vfs_setxattr_noperm.

Changelog:
- remove unused 'inode' variable.
Signed-off-by: NDmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

To prevent offline stripping of existing file xattrs and relabeling of
them at runtime, EVM allows only newly created files to be labeled.  As
pseudo filesystems are not persistent, stripping of xattrs is not a
concern.

Some LSMs defer file labeling on pseudo filesystems.  This patch
permits the labeling of existing files on pseudo files systems.
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

CONFIG_IMA_X509_PATH is always defined.  This patch removes the
IMA_X509_PATH definition and uses CONFIG_IMA_X509_PATH.
Signed-off-by: NDmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

File hashes are automatically set and updated and should not be
manually set. This patch limits file hash setting to fix and log
modes.
Signed-off-by: NDmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

Include don't appraise or measure rules for the NSFS filesystem
in the builtin ima_tcb and ima_appraise_tcb policies.

Changelog:
- Update documentation
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # 3.19

This patch adds a rule in the default measurement policy to skip inodes
in the cgroupfs filesystem. Measurements for this filesystem can be
avoided, as all the digests collected have the same value of the digest of
an empty file.

Furthermore, this patch updates the documentation of IMA policies in
Documentation/ABI/testing/ima_policy to make it consistent with
the policies set in security/integrity/ima/ima_policy.c.
Signed-off-by: NRoberto Sassu <rsassu@suse.de>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

It's a bit easier to read this if we split it up into two for loops.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

most of the ->d_inode uses there refer to the same inode IO would
go to, i.e. d_backing_inode()
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

/proc/keys is now mandatory and its config option no longer exists, so it
doesn't need selecting.
Reported-by: NPaul Bolle <pebolle@tiscali.nl>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: NJames Morris <james.l.morris@oracle.com>

Support for keyword 'boolean' will be dropped later on.

No functional change.

Reference: http://lkml.kernel.org/r/cover.1418003065.git.cj@linux.comSigned-off-by: NChristoph Jaeger <cj@linux.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

On powerpc we can end up with IMA=y and PPC_PSERIES=n which leads to:

 warning: (IMA) selects TCG_IBMVTPM which has unmet direct dependencies (TCG_TPM && PPC_PSERIES)
  tpm_ibmvtpm.c:(.text+0x14f3e8): undefined reference to `.plpar_hcall_norets'

I'm not sure why IMA needs to select those user-visible symbols, but if
it must then the simplest fix is to just express the proper dependencies
on the select.
Tested-by: NHon Ching (Vicky) Lo <lo1@us.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

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

integrity_kernel_read() duplicates the file read operations code
in vfs_read(). This patch refactors vfs_read() code creating a
helper function __vfs_read(). It is used by both vfs_read() and
integrity_kernel_read().
Signed-off-by: NDmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

This patch provides CONFIG_IMA_APPRAISE_SIGNED_INIT kernel configuration
option to force IMA appraisal using signatures. This is useful, when EVM
key is not initialized yet and we want securely initialize integrity or
any other functionality.

It forces embedded policy to require signature. Signed initialization
script can initialize EVM key, update the IMA policy and change further
requirement of everything to be signed.

Changes in v3:
* kernel parameter fixed to configuration option in the patch description

Changes in v2:
* policy change of this patch separated from the key loading patch
Signed-off-by: NDmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

Keys can only be loaded once the rootfs is mounted. Initcalls
are not suitable for that. This patch defines a special hook
to load the x509 public keys onto the IMA keyring, before
attempting to access any file. The keys are required for
verifying the file's signature. The hook is called after the
root filesystem is mounted and before the kernel calls 'init'.

Changes in v3:
* added more explanation to the patch description (Mimi)

Changes in v2:
* Hook renamed as 'integrity_load_keys()' to handle both IMA and EVM
  keys by integrity subsystem.
* Hook patch moved after defining loading functions
Signed-off-by: NDmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

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

Provide the function to load x509 certificates from the kernel into the
integrity kernel keyring.

Changes in v2:
* configuration option removed
* function declared as '__init'
Signed-off-by: NDmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

This patch defines a new function called integrity_read_file()
to read file from the kernel into a buffer. Subsequent patches
will read a file containing the public keys and load them onto
the IMA keyring.

This patch moves and renames ima_kernel_read(), the non-security
checking version of kernel_read(), to integrity_kernel_read().

Changes in v3:
* Patch descriptions improved (Mimi)
* Add missing cast (kbuild test robot)

Changes in v2:
* configuration option removed
* function declared as '__init'
Signed-off-by: NDmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

evm_inode_setxattr() can be called with no value. The function does not
check the length so that following command can be used to produce the
kernel oops: setfattr -n security.evm FOO. This patch fixes it.

Changes in v3:
* there is no reason to return different error codes for EVM_XATTR_HMAC
  and non EVM_XATTR_HMAC. Remove unnecessary test then.

Changes in v2:
* testing for validity of xattr type

[ 1106.396921] BUG: unable to handle kernel NULL pointer dereference at           (null)
[ 1106.398192] IP: [<ffffffff812af7b8>] evm_inode_setxattr+0x2a/0x48
[ 1106.399244] PGD 29048067 PUD 290d7067 PMD 0
[ 1106.399953] Oops: 0000 [#1] SMP
[ 1106.400020] Modules linked in: bridge stp llc evdev serio_raw i2c_piix4 button fuse
[ 1106.400020] CPU: 0 PID: 3635 Comm: setxattr Not tainted 3.16.0-kds+ #2936
[ 1106.400020] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 1106.400020] task: ffff8800291a0000 ti: ffff88002917c000 task.ti: ffff88002917c000
[ 1106.400020] RIP: 0010:[<ffffffff812af7b8>]  [<ffffffff812af7b8>] evm_inode_setxattr+0x2a/0x48
[ 1106.400020] RSP: 0018:ffff88002917fd50  EFLAGS: 00010246
[ 1106.400020] RAX: 0000000000000000 RBX: ffff88002917fdf8 RCX: 0000000000000000
[ 1106.400020] RDX: 0000000000000000 RSI: ffffffff818136d3 RDI: ffff88002917fdf8
[ 1106.400020] RBP: ffff88002917fd68 R08: 0000000000000000 R09: 00000000003ec1df
[ 1106.400020] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8800438a0a00
[ 1106.400020] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[ 1106.400020] FS:  00007f7dfa7d7740(0000) GS:ffff88005da00000(0000) knlGS:0000000000000000
[ 1106.400020] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1106.400020] CR2: 0000000000000000 CR3: 000000003763e000 CR4: 00000000000006f0
[ 1106.400020] Stack:
[ 1106.400020]  ffff8800438a0a00 ffff88002917fdf8 0000000000000000 ffff88002917fd98
[ 1106.400020]  ffffffff812a1030 ffff8800438a0a00 ffff88002917fdf8 0000000000000000
[ 1106.400020]  0000000000000000 ffff88002917fde0 ffffffff8116d08a ffff88002917fdc8
[ 1106.400020] Call Trace:
[ 1106.400020]  [<ffffffff812a1030>] security_inode_setxattr+0x5d/0x6a
[ 1106.400020]  [<ffffffff8116d08a>] vfs_setxattr+0x6b/0x9f
[ 1106.400020]  [<ffffffff8116d1e0>] setxattr+0x122/0x16c
[ 1106.400020]  [<ffffffff811687e8>] ? mnt_want_write+0x21/0x45
[ 1106.400020]  [<ffffffff8114d011>] ? __sb_start_write+0x10f/0x143
[ 1106.400020]  [<ffffffff811687e8>] ? mnt_want_write+0x21/0x45
[ 1106.400020]  [<ffffffff811687c0>] ? __mnt_want_write+0x48/0x4f
[ 1106.400020]  [<ffffffff8116d3e6>] SyS_setxattr+0x6e/0xb0
[ 1106.400020]  [<ffffffff81529da9>] system_call_fastpath+0x16/0x1b
[ 1106.400020] Code: c3 0f 1f 44 00 00 55 48 89 e5 41 55 49 89 d5 41 54 49 89 fc 53 48 89 f3 48 c7 c6 d3 36 81 81 48 89 df e8 18 22 04 00 85 c0 75 07 <41> 80 7d 00 02 74 0d 48 89 de 4c 89 e7 e8 5a fe ff ff eb 03 83
[ 1106.400020] RIP  [<ffffffff812af7b8>] evm_inode_setxattr+0x2a/0x48
[ 1106.400020]  RSP <ffff88002917fd50>
[ 1106.400020] CR2: 0000000000000000
[ 1106.428061] ---[ end trace ae08331628ba3050 ]---
Reported-by: NJan Kara <jack@suse.cz>
Signed-off-by: NDmitry Kasatkin <d.kasatkin@samsung.com>
Cc: stable@vger.kernel.org
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

ima_inode_setxattr() can be called with no value. Function does not
check the length so that following command can be used to produce
kernel oops: setfattr -n security.ima FOO. This patch fixes it.

Changes in v3:
* for stable reverted "allow setting hash only in fix or log mode"
  It will be a separate patch.

Changes in v2:
* testing validity of xattr type
* allow setting hash only in fix or log mode (Mimi)

[  261.562522] BUG: unable to handle kernel NULL pointer dereference at           (null)
[  261.564109] IP: [<ffffffff812af272>] ima_inode_setxattr+0x3e/0x5a
[  261.564109] PGD 3112f067 PUD 42965067 PMD 0
[  261.564109] Oops: 0000 [#1] SMP
[  261.564109] Modules linked in: bridge stp llc evdev serio_raw i2c_piix4 button fuse
[  261.564109] CPU: 0 PID: 3299 Comm: setxattr Not tainted 3.16.0-kds+ #2924
[  261.564109] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  261.564109] task: ffff8800428c2430 ti: ffff880042be0000 task.ti: ffff880042be0000
[  261.564109] RIP: 0010:[<ffffffff812af272>]  [<ffffffff812af272>] ima_inode_setxattr+0x3e/0x5a
[  261.564109] RSP: 0018:ffff880042be3d50  EFLAGS: 00010246
[  261.564109] RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000015
[  261.564109] RDX: 0000001500000000 RSI: 0000000000000000 RDI: ffff8800375cc600
[  261.564109] RBP: ffff880042be3d68 R08: 0000000000000000 R09: 00000000004d6256
[  261.564109] R10: 0000000000000000 R11: 0000000000000000 R12: ffff88002149ba00
[  261.564109] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[  261.564109] FS:  00007f6c1e219740(0000) GS:ffff88005da00000(0000) knlGS:0000000000000000
[  261.564109] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  261.564109] CR2: 0000000000000000 CR3: 000000003b35a000 CR4: 00000000000006f0
[  261.564109] Stack:
[  261.564109]  ffff88002149ba00 ffff880042be3df8 0000000000000000 ffff880042be3d98
[  261.564109]  ffffffff812a101b ffff88002149ba00 ffff880042be3df8 0000000000000000
[  261.564109]  0000000000000000 ffff880042be3de0 ffffffff8116d08a ffff880042be3dc8
[  261.564109] Call Trace:
[  261.564109]  [<ffffffff812a101b>] security_inode_setxattr+0x48/0x6a
[  261.564109]  [<ffffffff8116d08a>] vfs_setxattr+0x6b/0x9f
[  261.564109]  [<ffffffff8116d1e0>] setxattr+0x122/0x16c
[  261.564109]  [<ffffffff811687e8>] ? mnt_want_write+0x21/0x45
[  261.564109]  [<ffffffff8114d011>] ? __sb_start_write+0x10f/0x143
[  261.564109]  [<ffffffff811687e8>] ? mnt_want_write+0x21/0x45
[  261.564109]  [<ffffffff811687c0>] ? __mnt_want_write+0x48/0x4f
[  261.564109]  [<ffffffff8116d3e6>] SyS_setxattr+0x6e/0xb0
[  261.564109]  [<ffffffff81529da9>] system_call_fastpath+0x16/0x1b
[  261.564109] Code: 48 89 f7 48 c7 c6 58 36 81 81 53 31 db e8 73 27 04 00 85 c0 75 28 bf 15 00 00 00 e8 8a a5 d9 ff 84 c0 75 05 83 cb ff eb 15 31 f6 <41> 80 7d 00 03 49 8b 7c 24 68 40 0f 94 c6 e8 e1 f9 ff ff 89 d8
[  261.564109] RIP  [<ffffffff812af272>] ima_inode_setxattr+0x3e/0x5a
[  261.564109]  RSP <ffff880042be3d50>
[  261.564109] CR2: 0000000000000000
[  261.599998] ---[ end trace 39a89a3fc267e652 ]---
Reported-by: NJan Kara <jack@suse.cz>
Signed-off-by: NDmitry Kasatkin <d.kasatkin@samsung.com>
Cc: stable@vger.kernel.org
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

Replaced the use of a Variable Length Array In Struct (VLAIS) with a C99
compliant equivalent. This patch allocates the appropriate amount of memory
using a char array using the SHASH_DESC_ON_STACK macro.

The new code can be compiled with both gcc and clang.
Signed-off-by: NBehan Webster <behanw@converseincode.com>
Reviewed-by: NMark Charlebois <charlebm@gmail.com>
Reviewed-by: NJan-Simon Möller <dl9pf@gmx.de>
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Acked-by: NDmitry Kasatkin <d.kasatkin@samsung.com>
Cc: tglx@linutronix.de