hulk inclusion
category: feature
feature: IMA Digest Lists extension
bugzilla: 46797

---------------------------

With the patch to allow xattr/attr operations if a portable signature
verification fails, cp and tar can copy all xattrs/attrs so that at the
end of the process verification succeeds.

However, it might happen that the xattrs/attrs are already set to the
correct value (taken at signing time) and signature verification succeeds
before the copy has completed. For example, an archive might contains files
owned by root and the archive is extracted by root.

Then, since portable signatures are immutable, all subsequent operations
fail (e.g. fchown()), even if the operation is legitimate (does not alter
the current value).

This patch avoids this problem by reporting successful operation to user
space when that operation does not alter the current value of xattrs/attrs.
Signed-off-by: NRoberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: NJason Yan <yanaijie@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

hulk inclusion
category: feature
feature: IMA Digest Lists extension
bugzilla: 46797

---------------------------

If files with portable signatures are copied from one location to another
or are extracted from an archive, verification can temporarily fail until
all xattrs/attrs are set in the destination. Only portable signatures may
be moved or copied from one file to another, as they don't depend on
system-specific information such as the inode generation. Instead portable
signatures must include security.ima.

Unlike other security.evm types, EVM portable signatures are also
immutable. Thus, it wouldn't be a problem to allow xattr/attr operations
when verification fails, as portable signatures will never be replaced with
the HMAC on possibly corrupted xattrs/attrs.

This patch first introduces a new integrity status called
INTEGRITY_FAIL_IMMUTABLE, that allows callers of
evm_verify_current_integrity() to detect that a portable signature didn't
pass verification and then adds an exception in evm_protect_xattr() and
evm_inode_setattr() for this status and returns 0 instead of -EPERM.
Signed-off-by: NRoberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: NMimi Zohar <zohar@linux.ibm.com>
Reviewed-by: NJason Yan <yanaijie@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

hulk inclusion
category: feature
feature: IMA Digest Lists extension
bugzilla: 46797

---------------------------

When a file is being created, LSMs can set the initial label with the
inode_init_security hook. If no HMAC key is loaded, the new file will have
LSM xattrs but not the HMAC. It is also possible that the file remains
without protected xattrs after creation if no active LSM provided it.

Unfortunately, EVM will deny any further metadata operation on new files,
as evm_protect_xattr() will always return the INTEGRITY_NOLABEL error, or
INTEGRITY_NOXATTRS if no protected xattrs exist. This would limit the
usability of EVM when only a public key is loaded, as commands such as cp
or tar with the option to preserve xattrs won't work.

This patch ignores these errors when they won't be an issue, if no HMAC key
is loaded and cannot be loaded in the future (which can be enforced by
setting the EVM_SETUP_COMPLETE initialization flag).
Signed-off-by: NRoberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: NJason Yan <yanaijie@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

hulk inclusion
category: feature
feature: IMA Digest Lists extension
bugzilla: 46797

---------------------------

When EVM_ALLOW_METADATA_WRITES is set, EVM allows any operation on
metadata. Its main purpose is to allow users to freely set metadata when it
is protected by a portable signature, until an HMAC key is loaded.

However, callers of evm_verifyxattr() are not notified about metadata
changes and continue to rely on the last status returned by the function.
For example IMA, since it caches the appraisal result, will not call again
evm_verifyxattr() until the appraisal flags are cleared, and will grant
access to the file even if there was a metadata operation that made the
portable signature invalid.

This patch introduces evm_status_revalidate(), which callers of
evm_verifyxattr() can use in their xattr post hooks to determine whether
re-validation is necessary and to do the proper actions. IMA calls it in
its xattr post hooks to reset the appraisal flags, so that the EVM status
is re-evaluated after a metadata operation.

Lastly, this patch also adds a call to evm_reset_status() in
evm_inode_post_setattr() to invalidate the cached EVM status after a
setattr operation.
Signed-off-by: NRoberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: NJason Yan <yanaijie@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

hulk inclusion
category: feature
feature: IMA Digest Lists extension
bugzilla: 46797

---------------------------

evm_inode_init_security() requires an HMAC key to calculate the HMAC on
initial xattrs provided by LSMs. However, it checks generically whether a
key has been loaded, including also public keys, which is not correct as
public keys are not suitable to calculate the HMAC.

Originally, support for signature verification was introduced to verify a
possibly immutable initial ram disk, when no new files are created, and to
switch to HMAC for the root filesystem. By that time, an HMAC key should
have been loaded and usable to calculate HMACs for new files.

More recently support for requiring an HMAC key was removed from the
kernel, so that signature verification can be used alone. Since this is a
legitimate use case, evm_inode_init_security() should not return an error
when no HMAC key has been loaded.

This patch fixes this problem by replacing the evm_key_loaded() check with
a check of the EVM_INIT_HMAC flag in evm_initialized.

Cc: stable@vger.kernel.org # 4.5.x
Fixes: 26ddabfe ("evm: enable EVM when X509 certificate is loaded")
Signed-off-by: NRoberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: NMimi Zohar <zohar@linux.ibm.com>
Reviewed-by: NJason Yan <yanaijie@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

This patch checks the size for the EVM_IMA_XATTR_DIGSIG and
EVM_XATTR_PORTABLE_DIGSIG types to ensure that the algorithm is read from
the buffer returned by vfs_getxattr_alloc().

Cc: stable@vger.kernel.org # 4.19.x
Fixes: 5feeb611 ("evm: Allow non-SHA1 digital signatures")
Signed-off-by: NRoberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: NMimi Zohar <zohar@linux.ibm.com>

Don't silently ignore unknown or invalid ima_{policy,appraise,hash} and evm
kernel boot command line options.
Signed-off-by: NBruno Meneguele <bmeneg@redhat.com>
Signed-off-by: NMimi Zohar <zohar@linux.ibm.com>

This patch fixes the following warning and few other instances of
traversal of evm_config_xattrnames list:

[   32.848432] =============================
[   32.848707] WARNING: suspicious RCU usage
[   32.848966] 5.7.0-rc1-00006-ga8d5875ce5f0b #1 Not tainted
[   32.849308] -----------------------------
[   32.849567] security/integrity/evm/evm_main.c:231 RCU-list traversed in non-reader section!!

Since entries are only added to the list and never deleted, use
list_for_each_entry_lockless() instead of list_for_each_entry_rcu for
traversing the list.  Also, add a relevant comment in evm_secfs.c to
indicate this fact.
Reported-by: Nkernel test robot <lkp@intel.com>
Suggested-by: NPaul E. McKenney <paulmck@kernel.org>
Signed-off-by: NMadhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org> (RCU viewpoint)
Signed-off-by: NMimi Zohar <zohar@linux.ibm.com>

The #define for formatting log messages, pr_fmt, is duplicated in the
files under security/integrity.

This change moves the definition to security/integrity/integrity.h and
removes the duplicate definitions in the other files under
security/integrity.

With this change, the messages in the following files will be prefixed
with 'integrity'.

     security/integrity/platform_certs/platform_keyring.c
     security/integrity/platform_certs/load_powerpc.c
     security/integrity/platform_certs/load_uefi.c
     security/integrity/iint.c

     e.g. "integrity: Error adding keys to platform keyring %s\n"

And the messages in the following file will be prefixed with 'ima'.

     security/integrity/ima/ima_mok.c

     e.g. "ima: Allocating IMA blacklist keyring.\n"

For the rest of the files under security/integrity, there will be no
change in the message format.
Suggested-by: NShuah Khan <skhan@linuxfoundation.org>
Suggested-by: NJoe Perches <joe@perches.com>
Signed-off-by: NTushar Sugandhi <tusharsu@linux.microsoft.com>
Reviewed-by: NLakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: NMimi Zohar <zohar@linux.ibm.com>

Even though struct evm_ima_xattr_data includes a fixed-size array to hold a
SHA1 digest, most of the code ignores the array and uses the struct to mean
"type indicator followed by data of unspecified size" and tracks the real
size of what the struct represents in a separate length variable.

The only exception to that is the EVM code, which correctly uses the
definition of struct evm_ima_xattr_data.

So make this explicit in the code by removing the length specification from
the array in struct evm_ima_xattr_data. Also, change the name of the
element from digest to data since in most places the array doesn't hold a
digest.

A separate struct evm_xattr is introduced, with the original definition of
evm_ima_xattr_data to be used in the places that actually expect that
definition, specifically the EVM HMAC code.
Signed-off-by: NThiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: NMimi Zohar <zohar@linux.ibm.com>

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: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NAllison Randal <allison@lohutok.net>
Reviewed-by: NArmijn Hemel <armijn@tjaldur.nl>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fixes gcc '-Wunused-but-set-variable' warning:

security/integrity/evm/evm_main.c: In function 'init_evm':
security/integrity/evm/evm_main.c:566:21: warning:
 variable 'xattr' set but not used [-Wunused-but-set-variable]

Commit 21af7663 ("EVM: turn evm_config_xattrnames into a list")
defined and set "xattr", but never used it.

[zohar@linux.ibm.com: tweaked the patch description explanation]
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Signed-off-by: NMimi Zohar <zohar@linux.ibm.com>

The Makefile/Kconfig entry controlling compilation of this code is:

obj-$(CONFIG_EVM) += evm.o
evm-y := evm_main.o evm_crypto.o evm_secfs.o

security/integrity/evm/Kconfig:config EVM
security/integrity/evm/Kconfig: bool "EVM support"

...meaning that it currently is not being built as a module by anyone.

Lets remove the couple traces of modular infrastructure use, so that
when reading the driver there is no doubt it is builtin-only.

We also delete the MODULE_LICENSE tag etc. since all that information
is already contained at the top of the file in the comments.

Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: linux-ima-devel@lists.sourceforge.net
Cc: linux-security-module@vger.kernel.org
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NJames Morris <james.morris@microsoft.com>

SHA1 is reasonable in HMAC constructs, but it's desirable to be able to
use stronger hashes in digital signatures. Modify the EVM crypto code so
the hash type is imported from the digital signature and passed down to
the hash calculation code, and return the digest size to higher layers
for validation.
Signed-off-by: NMatthew Garrett <mjg59@google.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

Sites may wish to provide additional metadata alongside files in order
to make more fine-grained security decisions[1]. The security of this is
enhanced if this metadata is protected, something that EVM makes
possible. However, the kernel cannot know about the set of extended
attributes that local admins may wish to protect, and hardcoding this
policy in the kernel makes it difficult to change over time and less
convenient for distributions to enable.

This patch adds a new /sys/kernel/security/integrity/evm/evm_xattrs node,
which can be read to obtain the current set of EVM-protected extended
attributes or written to in order to add new entries. Extending this list
will not change the validity of any existing signatures provided that the
file in question does not have any of the additional extended attributes -
missing xattrs are skipped when calculating the EVM hash.

[1] For instance, a package manager could install information about the
package uploader in an additional extended attribute. Local LSM policy
could then be associated with that extended attribute in order to
restrict the privileges available to packages from less trusted
uploaders.
Signed-off-by: NMatthew Garrett <mjg59@google.com>
Reviewed-by: NJames Morris <james.morris@microsoft.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

Use a list of xattrs rather than an array - this makes it easier to
extend the list at runtime.
Signed-off-by: NMatthew Garrett <mjg59@google.com>
Reviewed-by: NJames Morris <james.morris@microsoft.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

EVM might update the evm xattr while the VFS performs a remount to
readonly mode. This is not properly checked for, additionally check
the s_readonly_remount superblock flag before writing.

The bug can for example be observed with UBIFS. UBIFS checks the free
space on the device before and after a remount. With EVM enabled the
free space sometimes differs between both checks.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

There is no gain from doing this except for some self-documenting.
Signed-off-by: NHernán Gonzalez <hernan@vanguardiasur.com.ar>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

These variables are not used where they are was defined.  There is no
point in declaring them there as extern.  Move and constify them, saving
2 bytes.

Function                                     old     new   delta
init_desc                                    273     271      -2
Total: Before=2112094, After=2112092, chg -0.00%
Signed-off-by: NHernán Gonzalez <hernan@vanguardiasur.com.ar>
Tested-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

The EVM signature includes the inode number and (optionally) the
filesystem UUID, making it impractical to ship EVM signatures in
packages. This patch adds a new portable format intended to allow
distributions to include EVM signatures. It is identical to the existing
format but hardcodes the inode and generation numbers to 0 and does not
include the filesystem UUID even if the kernel is configured to do so.

Removing the inode means that the metadata and signature from one file
could be copied to another file without invalidating it. This is avoided
by ensuring that an IMA xattr is present during EVM validation.

Portable signatures are intended to be immutable - ie, they will never
be transformed into HMACs.

Based on earlier work by Dmitry Kasatkin and Mikhail Kurinnoi.
Signed-off-by: NMatthew Garrett <mjg59@google.com>
Cc: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Cc: Mikhail Kurinnoi <viewizard@viewizard.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

When EVM is enabled it forbids modification of metadata protected by
EVM unless there is already a valid EVM signature. If any modification
is made, the kernel will then generate a new EVM HMAC. However, this
does not map well on use cases which use only asymmetric EVM signatures,
as in this scenario the kernel is unable to generate new signatures.

This patch extends the /sys/kernel/security/evm interface to allow
userland to request that modification of these xattrs be permitted. This
is only permitted if no keys have already been loaded. In this
configuration, modifying the metadata will invalidate the EVM appraisal
on the file in question. This allows packaging systems to write out new
files, set the relevant extended attributes and then move them into
place.

There's also some refactoring of the use of evm_initialized in order to
avoid heading down codepaths that assume there's a key available.
Signed-off-by: NMatthew Garrett <mjg59@google.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

Apparmor will be gaining support for security.apparmor labels, and it
would be helpful to include these in EVM validation now so appropriate
signatures can be generated even before full support is merged.
Signed-off-by: NMatthew Garrett <mjg59@google.com>
Acked-by: NJohn Johansen <John.johansen@canonical.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

Update files that depend on the magic.h inclusion.
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

In general the handling of IMA/EVM xattrs is good, but I found
a few locations where either the xattr size or the value of the
type field in the xattr are not checked. Add a few simple checks
to these locations to prevent malformed or malicious xattrs from
causing problems.
Signed-off-by: NSeth Forshee <seth.forshee@canonical.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

Right now, various places in the kernel check for the existence of
getxattr, setxattr, and removexattr inode operations and directly call
those operations.  Switch to helper functions and test for the IOP_XATTR
flag instead.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Acked-by: NJames Morris <james.l.morris@oracle.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

... and neither can ever be NULL
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This patch fixes vulnerability CVE-2016-2085.  The problem exists
because the vm_verify_hmac() function includes a use of memcmp().
Unfortunately, this allows timing side channel attacks; specifically
a MAC forgery complexity drop from 2^128 to 2^12.  This patch changes
the memcmp() to the cryptographically safe crypto_memneq().
Reported-by: NXiaofei Rex Guo <xiaofei.rex.guo@intel.com>
Signed-off-by: NRyan Ware <ware@linux.intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: NJames Morris <james.l.morris@oracle.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>

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>

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>

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>

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>

If filesystem is mounted read-only or file is immutable, updating
xattr will fail. This is a usual case during early boot until
filesystem is remount read-write. This patch verifies conditions
to skip unnecessary attempt to calculate HMAC and set xattr.

Changes in v2:
* indention changed according to Lindent (requested by Mimi)
Signed-off-by: NDmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

Unless an LSM labels a file during d_instantiate(), newly created
files are not labeled with an initial security.evm xattr, until
the file closes.  EVM, before allowing a protected, security xattr
to be written, verifies the existing 'security.evm' value is good.
For newly created files without a security.evm label, this
verification prevents writing any protected, security xattrs,
until the file closes.

Following is the example when this happens:
fd = open("foo", O_CREAT | O_WRONLY, 0644);
setxattr("foo", "security.SMACK64", value, sizeof(value), 0);
close(fd);

While INTEGRITY_NOXATTRS status is handled in other places, such
as evm_inode_setattr(), it does not handle it in all cases in
evm_protect_xattr().  By limiting the use of INTEGRITY_NOXATTRS to
newly created files, we can now allow setting "protected" xattrs.

Changelog:
- limit the use of INTEGRITY_NOXATTRS to IMA identified new files
Signed-off-by: NDmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org>  3.14+

This patch fixes a bug, where evm_verify_hmac() returns INTEGRITY_PASS
if inode->i_op->getxattr() returns an error in evm_find_protected_xattrs.
Signed-off-by: NDmitry Kasatkin <d.kasatkin@samsung.com>

This patch fixes checkpatch 'return' warnings introduced with commit
9819cf25 "checkpatch: warn on unnecessary void function return statements".

Use scripts/checkpatch.pl --file security/integrity/evm/evm_main.c
to produce the warnings.
Signed-off-by: NDmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>