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>

When EVM attempts to appraise a file signed with a crypto algorithm the
kernel doesn't have support for, it will cause the kernel to trigger a
module load. If the EVM policy includes appraisal of kernel modules this
will in turn call back into EVM - since EVM is holding a lock until the
crypto initialisation is complete, this triggers a deadlock. Add a
CRYPTO_NOLOAD flag and skip module loading if it's set, and add that flag
in the EVM case in order to fail gracefully with an error message
instead of deadlocking.
Signed-off-by: NMatthew Garrett <mjg59@google.com>
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

When CONFIG_SECURITYFS is not enabled, securityfs_create_dir returns
-ENODEV which throws the following error:
	"Unable to create integrity sysfs dir: -19"

However, if the feature is disabled, it can't be warning and hence
we need to silence the error. This patch checks for the error -ENODEV
which is returned when CONFIG_SECURITYFS is disabled to stop the error
being thrown.
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Acked-by: NMatthew Garrett <mjg59@google.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

The AUDIT_INTEGRITY_RULE is used for auditing IMA policy rules and
the IMA "audit" policy action.  This patch defines
AUDIT_INTEGRITY_POLICY_RULE to reflect the IMA policy rules.

Since we defined a new message type we can now also pass the
audit_context and get an associated SYSCALL record. This now produces
the following records when parsing IMA policy's rules:

type=UNKNOWN[1807] msg=audit(1527888965.738:320): action=audit \
  func=MMAP_CHECK mask=MAY_EXEC res=1
type=UNKNOWN[1807] msg=audit(1527888965.738:320): action=audit \
  func=FILE_CHECK mask=MAY_READ res=1
type=SYSCALL msg=audit(1527888965.738:320): arch=c000003e syscall=1 \
  success=yes exit=17 a0=1 a1=55bcfcca9030 a2=11 a3=7fcc1b55fb38 \
  items=0 ppid=1567 pid=1601 auid=0 uid=0 gid=0 euid=0 suid=0 \
  fsuid=0 egid=0 sgid=0 fsgid=0 tty=tty2 ses=2 comm="echo" \
  exe="/usr/bin/echo" \
  subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)
Signed-off-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Acked-by: NPaul Moore <paul@paul-moore.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

If Integrity is not auditing, IMA shouldn't audit, either.
Signed-off-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Acked-by: NPaul Moore <paul@paul-moore.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

Remove the usage of audit_log_string() and replace it with
audit_log_format().
Signed-off-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Suggested-by: NSteve Grubb <sgrubb@redhat.com>
Acked-by: NPaul Moore <paul@paul-moore.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

The parameters passed to this logging function are all provided by
a privileged user and therefore we can call audit_log_string()
rather than audit_log_untrustedstring().
Signed-off-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Suggested-by: NSteve Grubb <sgrubb@redhat.com>
Acked-by: NPaul Moore <paul@paul-moore.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

Some systems are memory constrained but they need to load very large
firmwares.  The firmware subsystem allows drivers to request this
firmware be loaded from the filesystem, but this requires that the
entire firmware be loaded into kernel memory first before it's provided
to the driver.  This can lead to a situation where we map the firmware
twice, once to load the firmware into kernel memory and once to copy the
firmware into the final resting place.

To resolve this problem, commit a098ecd2 ("firmware: support loading
into a pre-allocated buffer") introduced request_firmware_into_buf() API
that allows drivers to request firmware be loaded directly into a
pre-allocated buffer.

Do devices using pre-allocated memory run the risk of the firmware being
accessible to the device prior to the completion of IMA's signature
verification any more than when using two buffers? (Refer to mailing list
discussion[1]).

Only on systems with an IOMMU can the access be prevented.  As long as
the signature verification completes prior to the DMA map is performed,
the device can not access the buffer.  This implies that the same buffer
can not be re-used.  Can we ensure the buffer has not been DMA mapped
before using the pre-allocated buffer?

[1] https://lkml.org/lkml/2018/7/10/56Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NJames Morris <james.morris@microsoft.com>

Both the init_module and finit_module syscalls call either directly
or indirectly the security_kernel_read_file LSM hook.  This patch
replaces the direct call in init_module with a call to the new
security_kernel_load_data hook and makes the corresponding changes
in SELinux, LoadPin, and IMA.
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: NJessica Yu <jeyu@kernel.org>
Acked-by: NPaul Moore <paul@paul-moore.com>
Acked-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NJames Morris <james.morris@microsoft.com>

IMA by default does not measure, appraise or audit files, but can be
enabled at runtime by specifying a builtin policy on the boot command line
or by loading a custom policy.

This patch defines a build time policy, which verifies kernel modules,
firmware, kexec image, and/or the IMA policy signatures.  This build time
policy is automatically enabled at runtime and persists after loading a
custom policy.
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NJames Morris <james.morris@microsoft.com>

With an IMA policy requiring signed firmware, this patch prevents
the sysfs fallback method of loading firmware.
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Matthew Garrett <mjg59@google.com>
Signed-off-by: NJames Morris <james.morris@microsoft.com>

The original kexec_load syscall can not verify file signatures, nor can
the kexec image be measured.  Based on policy, deny the kexec_load
syscall.
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Reviewed-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NJames Morris <james.morris@microsoft.com>

We need to unlock before returning on this error path.

Fixes: fa516b66 ("EVM: Allow runtime modification of the set of verified xattrs")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

If the user sets xattr->name[0] to NUL then we would read one character
before the start of the array.  This bug seems harmless as far as I can
see but perhaps it would trigger a warning in KASAN.

Fixes: fa516b66 ("EVM: Allow runtime modification of the set of verified xattrs")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

In the case where the allocation of xattr fails and xattr is NULL, the
error exit return path via label 'out' will dereference xattr when
kfree'ing xattr-name.  Fix this by only kfree'ing xattr->name and xattr
when xattr is non-null.

Detected by CoverityScan, CID#1469366 ("Dereference after null check")

Fixes: fa516b66 ("EVM: Allow runtime modification of the set of verified xattrs")
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

The allocation of 'temp' is not kfree'd and hence there is a memory
leak on each call of evm_read_xattrs.  Fix this by kfree'ing it
after copying data from it back to the user space buffer 'buf'.

Detected by CoverityScan, CID#1469386 ("Resource Leak")

Fixes: fa516b66 ("EVM: Allow runtime modification of the set of verified xattrs")
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

Use list_splice_tail_init_rcu() to extend the existing custom IMA policy
with additional IMA policy rules.
Signed-off-by: NPetko Manolov <petko.manolov@konsulko.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

match_string() returns the index of an array for a matching string,
which can be used intead of open coded variant.
Signed-off-by: NYisheng Xie <xieyisheng1@huawei.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

As IMA policy rules are added, a mask of the type of rule (eg. kernel
modules, firmware, IMA policy) is updated.  Unlike custom IMA policy
rules, which replace the original builtin policy rules and update the
mask, the builtin "secure_boot" policy rules were loaded, but did not
update the mask.

This patch refactors the code to load custom policies, defining a new
function named ima_appraise_flag().  The new function is called either
when loading the builtin "secure_boot" or custom policies.

Fixes: 503ceaef ("ima: define a set of appraisal rules requiring file signatures")
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

Don't differentiate, for now, between kernel_read_file_id READING_FIRMWARE
and READING_FIRMWARE_PREALLOC_BUFFER enumerations.

Fixes: a098ecd2 firmware: support loading into a pre-allocated buffer (since 4.8)
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Serge E. Hallyn <serge@hallyn.com>
Cc: Stephen Boyd <stephen.boyd@linaro.org>

If/when file data signatures are distributed with the file data, this
patch will not be needed.  In the current environment where only some
files are signed, the ability to differentiate between file systems is
needed.  Some file systems consider the file system magic number
internal to the file system.

This patch defines a new IMA policy condition named "fsname", based on
the superblock's file_system_type (sb->s_type) name. This allows policy
rules to be expressed in terms of the filesystem name.

The following sample rules require file signatures on rootfs files
executed or mmap'ed.

appraise func=BPRM_CHECK fsname=rootfs appraise_type=imasig
appraise func=FILE_MMAP fsname=rootfs appraise_type=imasig
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Theodore Ts'o <tytso@mit.edu>

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>

We want to add additional evm control nodes, and it'd be preferable not
to clutter up the securityfs root directory any further. Create a new
integrity directory, move the ima directory into it, create an evm
directory for the evm attribute and add compatibility symlinks.
Signed-off-by: NMatthew Garrett <mjg59@google.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

Commit a756024e ("ima: added ima_policy_flag variable") replaced
ima_initialized with ima_policy_flag, but didn't remove ima_initialized.
This patch removes it.
Signed-off-by: NPetr Vorel <pvorel@suse.cz>
Reviewed-by: NJames Morris <james.morris@microsoft.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

Define pr_fmt everywhere.
Signed-off-by: NPetr Vorel <pvorel@suse.cz>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>  (powerpc build error)
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

Changelog:
Previous pr_fmt definition was too late and caused problems in powerpc
allyesconfg build.

Kernel configured as CONFIG_IMA_READ_POLICY=y && CONFIG_IMA_WRITE_POLICY=n
keeps 0600 mode after loading policy. Remove write permission to state
that policy file no longer be written.
Signed-off-by: NPetr Vorel <pvorel@suse.cz>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

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

The kernel should not calculate new hmacs for mounts done by
non-root users. Update evm_calc_hmac_or_hash() to refuse to
calculate new hmacs for mounts for non-init user namespaces.

Cc: linux-integrity@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: James Morris <james.l.morris@oracle.com>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Signed-off-by: NSeth Forshee <seth.forshee@canonical.com>
Signed-off-by: NDongsu Park <dongsu@kinvolk.io>
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>

IMA requires having it's hash algorithm be compiled-in due to it's
early use.  The default IMA algorithm is protected by Kconfig to be
compiled-in.

The ima_hash kernel parameter allows to choose the hash algorithm. When
the specified algorithm is not available or available as a module, IMA
initialization fails, which leads to a kernel panic (mknodat syscall calls
ima_post_path_mknod()).  Therefore as fallback we force IMA to use
the default builtin Kconfig hash algorithm.

Fixed crash:

$ grep CONFIG_CRYPTO_MD4 .config
CONFIG_CRYPTO_MD4=m

[    0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-4.12.14-2.3-default root=UUID=74ae8202-9ca7-4e39-813b-22287ec52f7a video=1024x768-16 plymouth.ignore-serial-consoles console=ttyS0 console=tty resume=/dev/disk/by-path/pci-0000:00:07.0-part3 splash=silent showopts ima_hash=md4
...
[    1.545190] ima: Can not allocate md4 (reason: -2)
...
[    2.610120] BUG: unable to handle kernel NULL pointer dereference at           (null)
[    2.611903] IP: ima_match_policy+0x23/0x390
[    2.612967] PGD 0 P4D 0
[    2.613080] Oops: 0000 [#1] SMP
[    2.613080] Modules linked in: autofs4
[    2.613080] Supported: Yes
[    2.613080] CPU: 0 PID: 1 Comm: systemd Not tainted 4.12.14-2.3-default #1
[    2.613080] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014
[    2.613080] task: ffff88003e2d0040 task.stack: ffffc90000190000
[    2.613080] RIP: 0010:ima_match_policy+0x23/0x390
[    2.613080] RSP: 0018:ffffc90000193e88 EFLAGS: 00010296
[    2.613080] RAX: 0000000000000000 RBX: 000000000000000c RCX: 0000000000000004
[    2.613080] RDX: 0000000000000010 RSI: 0000000000000001 RDI: ffff880037071728
[    2.613080] RBP: 0000000000008000 R08: 0000000000000000 R09: 0000000000000000
[    2.613080] R10: 0000000000000008 R11: 61c8864680b583eb R12: 00005580ff10086f
[    2.613080] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000008000
[    2.613080] FS:  00007f5c1da08940(0000) GS:ffff88003fc00000(0000) knlGS:0000000000000000
[    2.613080] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    2.613080] CR2: 0000000000000000 CR3: 0000000037002000 CR4: 00000000003406f0
[    2.613080] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[    2.613080] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[    2.613080] Call Trace:
[    2.613080]  ? shmem_mknod+0xbf/0xd0
[    2.613080]  ima_post_path_mknod+0x1c/0x40
[    2.613080]  SyS_mknod+0x210/0x220
[    2.613080]  entry_SYSCALL_64_fastpath+0x1a/0xa5
[    2.613080] RIP: 0033:0x7f5c1bfde570
[    2.613080] RSP: 002b:00007ffde1c90dc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000085
[    2.613080] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5c1bfde570
[    2.613080] RDX: 0000000000000000 RSI: 0000000000008000 RDI: 00005580ff10086f
[    2.613080] RBP: 00007ffde1c91040 R08: 00005580ff10086f R09: 0000000000000000
[    2.613080] R10: 0000000000104000 R11: 0000000000000246 R12: 00005580ffb99660
[    2.613080] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000002
[    2.613080] Code: 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 41 57 41 56 44 8d 14 09 41 55 41 54 55 53 44 89 d3 09 cb 48 83 ec 38 48 8b 05 c5 03 29 01 <4c> 8b 20 4c 39 e0 0f 84 d7 01 00 00 4c 89 44 24 08 89 54 24 20
[    2.613080] RIP: ima_match_policy+0x23/0x390 RSP: ffffc90000193e88
[    2.613080] CR2: 0000000000000000
[    2.613080] ---[ end trace 9a9f0a8a73079f6a ]---
[    2.673052] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009
[    2.673052]
[    2.675337] Kernel Offset: disabled
[    2.676405] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009
Signed-off-by: NPetr Vorel <pvorel@suse.cz>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

This is required to use SMACK and IMA/EVM together. Add it to the
default nomeasure/noappraise list like other pseudo filesystems.
Signed-off-by: NMartin Townsend <mtownsend1973@gmail.com>
Acked-by: NCasey Schaufler <casey@schaufler-ca.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>

Replace nested ifs in the EVM xattr verification logic with a switch
statement, making the code easier to understand.

Also, add comments to the if statements in the out section and constify the
cause variable.
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: NThiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Acked-by: NSerge Hallyn <serge@hallyn.com>

The "goto out" statement doesn't have any purpose since there's no cleanup
to be done when returning early, so remove it. This also makes the rc
variable unnecessary so remove it as well.

Also, the xattr_len and fmt variables are redundant so remove them as well.
Signed-off-by: NThiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Acked-by: NSerge Hallyn <serge@hallyn.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

This macro isn't used anymore since commit 0d73a552 ("ima: re-introduce
own integrity cache lock"), so remove it.
Signed-off-by: NThiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Acked-by: NSerge Hallyn <serge@hallyn.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

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

TPM_CRB driver provides TPM CRB 2.0 support.  If it is built as a
module, the TPM chip is registered after IMA init.  tpm_pcr_read() in
IMA fails and displays the following message even though eventually
there is a TPM chip on the system.

ima: No TPM chip found, activating TPM-bypass! (rc=-19)

Fix IMA Kconfig to select TPM_CRB so TPM_CRB driver is built in the kernel
and initializes before IMA.
Signed-off-by: NJiandi An <anjiandi@codeaurora.org>
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>

This patch addresses the fuse privileged mounted filesystems in
environments which are unwilling to accept the risk of trusting the
signature verification and want to always fail safe, but are for example
using a pre-built kernel.

This patch defines a new builtin policy named "fail_securely", which can
be specified on the boot command line as an argument to "ima_policy=".
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Seth Forshee <seth.forshee@canonical.com>
Cc: Dongsu Park <dongsu@kinvolk.io>
Cc: Alban Crequy <alban@kinvolk.io>
Acked-by: NSerge Hallyn <serge@hallyn.com>
Acked-by: N"Eric W. Biederman" <ebiederm@xmission.com>