Commit Graph

381 Commits

Author SHA1 Message Date
Petr Vorel ab60368ab6 ima: Fallback to the builtin hash algorithm
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: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-03-25 07:26:32 -04:00
Martin Townsend 1c070b18d4 ima: Add smackfs to the default appraise/measure list
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: Martin Townsend <mtownsend1973@gmail.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-03-25 07:26:31 -04:00
Thiago Jung Bauermann f5e51fa368 ima: Improvements in ima_appraise_measurement()
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: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
2018-03-25 07:26:30 -04:00
Thiago Jung Bauermann 1775cb87b0 ima: Simplify ima_eventsig_init()
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: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-03-25 07:26:29 -04:00
Tycho Andersen e456ef88ae 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>
2018-03-25 07:26:28 -04:00
Jiandi An fac37c628f ima: Fix Kconfig to select TPM 2.0 CRB interface
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: Jiandi An <anjiandi@codeaurora.org>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-03-25 07:24:31 -04:00
Mimi Zohar 9e67028e76 ima: fail signature verification based on policy
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: Mimi 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: Serge Hallyn <serge@hallyn.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-03-23 06:31:37 -04:00
Mimi Zohar a9a4935d44 ima: clear IMA_HASH
The IMA_APPRAISE and IMA_HASH policies overlap. Clear IMA_HASH properly.

Fixes: da1b0029f5 ("ima: support new "hash" and "dont_hash" policy actions")
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-03-23 06:31:37 -04:00
Mimi Zohar d77ccdc644 ima: re-evaluate files on privileged mounted filesystems
This patch addresses the fuse privileged mounted filesystems in a "secure"
environment, with a correctly enforced security policy, which is willing
to assume the inherent risk of specific fuse filesystems that are well
defined and properly implemented.

As there is no way for the kernel to detect file changes, the kernel
ignores the cached file integrity results and re-measures, re-appraises,
and re-audits the file.

Signed-off-by: Mimi 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: Serge Hallyn <serge@hallyn.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-03-23 06:31:37 -04:00
Mimi Zohar 57b56ac6fe ima: fail file signature verification on non-init mounted filesystems
FUSE can be mounted by unprivileged users either today with fusermount
installed with setuid, or soon with the upcoming patches to allow FUSE
mounts in a non-init user namespace.

This patch addresses the new unprivileged non-init mounted filesystems,
which are untrusted, by failing the signature verification.

This patch defines two new flags SB_I_IMA_UNVERIFIABLE_SIGNATURE and
SB_I_UNTRUSTED_MOUNTER.

Signed-off-by: Mimi 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: Serge Hallyn <serge@hallyn.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-03-23 06:31:37 -04:00
Matthew Garrett d906c10d8a 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
2018-03-23 06:31:11 -04:00
Goffredo Baroncelli c472c07bfe iversion: Rename make inode_cmp_iversion{+raw} to inode_eq_iversion{+raw}
The function inode_cmp_iversion{+raw} is counter-intuitive, because it
returns true when the counters are different and false when these are equal.

Rename it to inode_eq_iversion{+raw}, which will returns true when
the counters are equal and false otherwise.

Signed-off-by: Goffredo Baroncelli <kreijack@inwind.it>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
2018-02-01 08:15:25 -05:00
Linus Torvalds ae0cb7be35 Merge branch 'next-tpm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull tpm updates from James Morris:

 - reduce polling delays in tpm_tis

 - support retrieving TPM 2.0 Event Log through EFI before
   ExitBootServices

 - replace tpm-rng.c with a hwrng device managed by the driver for each
   TPM device

 - TPM resource manager synthesizes TPM_RC_COMMAND_CODE response instead
   of returning -EINVAL for unknown TPM commands. This makes user space
   more sound.

 - CLKRUN fixes:

    * Keep #CLKRUN disable through the entier TPM command/response flow

    * Check whether #CLKRUN is enabled before disabling and enabling it
      again because enabling it breaks PS/2 devices on a system where it
      is disabled

* 'next-tpm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  tpm: remove unused variables
  tpm: remove unused data fields from I2C and OF device ID tables
  tpm: only attempt to disable the LPC CLKRUN if is already enabled
  tpm: follow coding style for variable declaration in tpm_tis_core_init()
  tpm: delete the TPM_TIS_CLK_ENABLE flag
  tpm: Update MAINTAINERS for Jason Gunthorpe
  tpm: Keep CLKRUN enabled throughout the duration of transmit_cmd()
  tpm_tis: Move ilb_base_addr to tpm_tis_data
  tpm2-cmd: allow more attempts for selftest execution
  tpm: return a TPM_RC_COMMAND_CODE response if command is not implemented
  tpm: Move Linux RNG connection to hwrng
  tpm: use struct tpm_chip for tpm_chip_find_get()
  tpm: parse TPM event logs based on EFI table
  efi: call get_event_log before ExitBootServices
  tpm: add event log format version
  tpm: rename event log provider files
  tpm: move tpm_eventlog.h outside of drivers folder
  tpm: use tpm_msleep() value as max delay
  tpm: reduce tpm polling delay in tpm_tis_core
  tpm: move wait_for_tpm_stat() to respective driver files
2018-01-31 13:12:31 -08:00
Linus Torvalds 3c29548f87 Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull integrity updates from James Morris:
 "This contains a mixture of bug fixes, code cleanup, and new
  functionality. Of note is the integrity cache locking fix, file change
  detection, and support for a new EVM portable and immutable signature
  type.

  The re-introduction of the integrity cache lock (iint) fixes the
  problem of attempting to take the i_rwsem shared a second time, when
  it was previously taken exclusively. Defining atomic flags resolves
  the original iint/i_rwsem circular locking - accessing the file data
  vs. modifying the file metadata. Although it fixes the O_DIRECT
  problem as well, a subsequent patch is needed to remove the explicit
  O_DIRECT prevention.

  For performance reasons, detecting when a file has changed and needs
  to be re-measured, re-appraised, and/or re-audited, was limited to
  after the last writer has closed, and only if the file data has
  changed. Detecting file change is based on i_version. For filesystems
  that do not support i_version, remote filesystems, or userspace
  filesystems, the file was measured, appraised and/or audited once and
  never re-evaluated. Now local filesystems, which do not support
  i_version or are not mounted with the i_version option, assume the
  file has changed and are required to re-evaluate the file. This change
  does not address detecting file change on remote or userspace
  filesystems.

  Unlike file data signatures, which can be included and distributed in
  software packages (eg. rpm, deb), the existing EVM signature, which
  protects the file metadata, could not be included in software
  packages, as it includes file system specific information (eg. i_ino,
  possibly the UUID). This pull request defines a new EVM portable and
  immutable file metadata signature format, which can be included in
  software packages"

* 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  ima/policy: fix parsing of fsuuid
  ima: Use i_version only when filesystem supports it
  integrity: remove unneeded initializations in integrity_iint_cache entries
  ima: log message to module appraisal error
  ima: pass filename to ima_rdwr_violation_check()
  ima: Fix line continuation format
  ima: support new "hash" and "dont_hash" policy actions
  ima: re-introduce own integrity cache lock
  EVM: Add support for portable signature format
  EVM: Allow userland to permit modification of EVM-protected metadata
  ima: relax requiring a file signature for new files with zero length
2018-01-31 13:07:35 -08:00
Jeff Layton 3b370b215f IMA: switch IMA over to new i_version API
Signed-off-by: Jeff Layton <jlayton@redhat.com>
2018-01-29 06:42:21 -05:00
Mike Rapoport 36447456e1 ima/policy: fix parsing of fsuuid
The switch to uuid_t invereted the logic of verfication that &entry->fsuuid
is zero during parsing of "fsuuid=" rule. Instead of making sure the
&entry->fsuuid field is not attempted to be overwritten, we bail out for
perfectly correct rule.

Fixes: 787d8c530a ("ima/policy: switch to use uuid_t")

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-01-18 16:52:49 -05:00
Jarkko Sakkinen aad887f664 tpm: use struct tpm_chip for tpm_chip_find_get()
Device number (the character device index) is not a stable identifier
for a TPM chip. That is the reason why every call site passes
TPM_ANY_NUM to tpm_chip_find_get().

This commit changes the API in a way that instead a struct tpm_chip
instance is given and NULL means the default chip. In addition, this
commit refines the documentation to be up to date with the
implementation.

Suggested-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> (@chip_num -> @chip part)
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@ziepe.ca>
Tested-by: PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>
2018-01-08 12:58:36 +02:00
Sascha Hauer a2a2c3c858 ima: Use i_version only when filesystem supports it
i_version is only supported by a filesystem when the SB_I_VERSION
flag is set. This patch tests for the SB_I_VERSION flag before using
i_version. If we can't use i_version to detect a file change then we
must assume the file has changed in the last_writer path and remeasure
it.

On filesystems without i_version support IMA used to measure a file
only once and didn't detect any changes to a file. With this patch
IMA now works properly on these filesystems.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-18 09:43:49 -05:00
Bruno E. O. Meneguele 9c655be064 ima: log message to module appraisal error
Simple but useful message log to the user in case of module appraise is
forced and fails due to the lack of file descriptor, that might be
caused by kmod calls to compressed modules.

Signed-off-by: Bruno E. O. Meneguele <brdeoliv@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-18 09:43:48 -05:00
Roberto Sassu 4e8581eefe ima: pass filename to ima_rdwr_violation_check()
ima_rdwr_violation_check() retrieves the full path of a measured file by
calling ima_d_path(). If process_measurement() calls this function, it
reuses the pointer and passes it to the functions to measure/appraise/audit
an accessed file.

After commit bc15ed663e ("ima: fix ima_d_path() possible race with
rename"), ima_d_path() first tries to retrieve the full path by calling
d_absolute_path() and, if there is an error, copies the dentry name to the
buffer passed as argument.

However, ima_rdwr_violation_check() passes to ima_d_path() the pointer of a
local variable. process_measurement() might be reusing the pointer to an
area in the stack which may have been already overwritten after
ima_rdwr_violation_check() returned.

Correct this issue by passing to ima_rdwr_violation_check() the pointer of
a buffer declared in process_measurement().

Fixes: bc15ed663e ("ima: fix ima_d_path() possible race with rename")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-18 09:43:48 -05:00
Joe Perches 72bf83b0c9 ima: Fix line continuation format
Line continuations with excess spacing causes unexpected output.

Based on commit 6f76b6fcaa ("CodingStyle: Document the exception of
not splitting user-visible strings, for grepping") recommendation.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-18 09:43:47 -05:00
Mimi Zohar da1b0029f5 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>
2017-12-18 09:43:38 -05:00
Sascha Hauer ac0bf025d2 ima: Use i_version only when filesystem supports it
i_version is only supported by a filesystem when the SB_I_VERSION
flag is set. This patch tests for the SB_I_VERSION flag before using
i_version. If we can't use i_version to detect a file change then we
must assume the file has changed in the last_writer path and remeasure
it.

On filesystems without i_version support IMA used to measure a file
only once and didn't detect any changes to a file. With this patch
IMA now works properly on these filesystems.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
2017-12-13 07:23:02 -05:00
Dmitry Kasatkin 0d73a55208 ima: re-introduce own integrity cache lock
Before IMA appraisal was introduced, IMA was using own integrity cache
lock along with i_mutex. process_measurement and ima_file_free took
the iint->mutex first and then the i_mutex, while setxattr, chmod and
chown took the locks in reverse order. To resolve the potential deadlock,
i_mutex was moved to protect entire IMA functionality and the redundant
iint->mutex was eliminated.

Solution was based on the assumption that filesystem code does not take
i_mutex further. But when file is opened with O_DIRECT flag, direct-io
implementation takes i_mutex and produces deadlock. Furthermore, certain
other filesystem operations, such as llseek, also take i_mutex.

More recently some filesystems have replaced their filesystem specific
lock with the global i_rwsem to read a file.  As a result, when IMA
attempts to calculate the file hash, reading the file attempts to take
the i_rwsem again.

To resolve O_DIRECT related deadlock problem, this patch re-introduces
iint->mutex. But to eliminate the original chmod() related deadlock
problem, this patch eliminates the requirement for chmod hooks to take
the iint->mutex by introducing additional atomic iint->attr_flags to
indicate calling of the hooks. The allowed locking order is to take
the iint->mutex first and then the i_rwsem.

Original flags were cleared in chmod(), setxattr() or removwxattr()
hooks and tested when file was closed or opened again. New atomic flags
are set or cleared in those hooks and tested to clear iint->flags on
close or on open.

Atomic flags are following:
* IMA_CHANGE_ATTR - indicates that chATTR() was called (chmod, chown,
  chgrp) and file attributes have changed. On file open, it causes IMA
  to clear iint->flags to re-evaluate policy and perform IMA functions
  again.
* IMA_CHANGE_XATTR - indicates that setxattr or removexattr was called
  and extended attributes have changed. On file open, it causes IMA to
  clear iint->flags IMA_DONE_MASK to re-appraise.
* IMA_UPDATE_XATTR - indicates that security.ima needs to be updated.
  It is cleared if file policy changes and no update is needed.
* IMA_DIGSIG - indicates that file security.ima has signature and file
  security.ima must not update to file has on file close.
* IMA_MUST_MEASURE - indicates the file is in the measurement policy.

Fixes: Commit 6552321831 ("xfs: remove i_iolock and use i_rwsem in
the VFS inode instead")

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-11 17:20:47 -05:00
Matthew Garrett 50b977481f EVM: Add support for portable signature format
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: Matthew Garrett <mjg59@google.com>
Cc: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Cc: Mikhail Kurinnoi <viewizard@viewizard.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-11 17:20:39 -05:00
Mimi Zohar b7e27bc1d4 ima: relax requiring a file signature for new files with zero length
Custom policies can require file signatures based on LSM labels.  These
files are normally created and only afterwards labeled, requiring them
to be signed.

Instead of requiring file signatures based on LSM labels, entire
filesystems could require file signatures.  In this case, we need the
ability of writing new files without requiring file signatures.

The definition of a "new" file was originally defined as any file with
a length of zero.  Subsequent patches redefined a "new" file to be based
on the FILE_CREATE open flag.  By combining the open flag with a file
size of zero, this patch relaxes the file signature requirement.

Fixes: 1ac202e978 ima: accept previously set IMA_NEW_FILE
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-11 14:26:26 -05:00
Roberto Sassu 020aae3ee5 ima: do not update security.ima if appraisal status is not INTEGRITY_PASS
Commit b65a9cfc2c ("Untangling ima mess, part 2: deal with counters")
moved the call of ima_file_check() from may_open() to do_filp_open() at a
point where the file descriptor is already opened.

This breaks the assumption made by IMA that file descriptors being closed
belong to files whose access was granted by ima_file_check(). The
consequence is that security.ima and security.evm are updated with good
values, regardless of the current appraisal status.

For example, if a file does not have security.ima, IMA will create it after
opening the file for writing, even if access is denied. Access to the file
will be allowed afterwards.

Avoid this issue by checking the appraisal status before updating
security.ima.

Cc: stable@vger.kernel.org
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-11-20 08:23:10 +11:00
Linus Torvalds 37dc79565c Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto updates from Herbert Xu:
 "Here is the crypto update for 4.15:

  API:

   - Disambiguate EBUSY when queueing crypto request by adding ENOSPC.
     This change touches code outside the crypto API.
   - Reset settings when empty string is written to rng_current.

  Algorithms:

   - Add OSCCA SM3 secure hash.

  Drivers:

   - Remove old mv_cesa driver (replaced by marvell/cesa).
   - Enable rfc3686/ecb/cfb/ofb AES in crypto4xx.
   - Add ccm/gcm AES in crypto4xx.
   - Add support for BCM7278 in iproc-rng200.
   - Add hash support on Exynos in s5p-sss.
   - Fix fallback-induced error in vmx.
   - Fix output IV in atmel-aes.
   - Fix empty GCM hash in mediatek.

  Others:

   - Fix DoS potential in lib/mpi.
   - Fix potential out-of-order issues with padata"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (162 commits)
  lib/mpi: call cond_resched() from mpi_powm() loop
  crypto: stm32/hash - Fix return issue on update
  crypto: dh - Remove pointless checks for NULL 'p' and 'g'
  crypto: qat - Clean up error handling in qat_dh_set_secret()
  crypto: dh - Don't permit 'key' or 'g' size longer than 'p'
  crypto: dh - Don't permit 'p' to be 0
  crypto: dh - Fix double free of ctx->p
  hwrng: iproc-rng200 - Add support for BCM7278
  dt-bindings: rng: Document BCM7278 RNG200 compatible
  crypto: chcr - Replace _manual_ swap with swap macro
  crypto: marvell - Add a NULL entry at the end of mv_cesa_plat_id_table[]
  hwrng: virtio - Virtio RNG devices need to be re-registered after suspend/resume
  crypto: atmel - remove empty functions
  crypto: ecdh - remove empty exit()
  MAINTAINERS: update maintainer for qat
  crypto: caam - remove unused param of ctx_map_to_sec4_sg()
  crypto: caam - remove unneeded edesc zeroization
  crypto: atmel-aes - Reset the controller before each use
  crypto: atmel-aes - properly set IV after {en,de}crypt
  hwrng: core - Reset user selected rng by writing "" to rng_current
  ...
2017-11-14 10:52:09 -08:00
Linus Torvalds b33e3cc5c9 Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem integrity updates from James Morris:
 "There is a mixture of bug fixes, code cleanup, preparatory code for
  new functionality and new functionality.

  Commit 26ddabfe96 ("evm: enable EVM when X509 certificate is
  loaded") enabled EVM without loading a symmetric key, but was limited
  to defining the x509 certificate pathname at build. Included in this
  set of patches is the ability of enabling EVM, without loading the EVM
  symmetric key, from userspace. New is the ability to prevent the
  loading of an EVM symmetric key."

* 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  ima: Remove redundant conditional operator
  ima: Fix bool initialization/comparison
  ima: check signature enforcement against cmdline param instead of CONFIG
  module: export module signature enforcement status
  ima: fix hash algorithm initialization
  EVM: Only complain about a missing HMAC key once
  EVM: Allow userspace to signal an RSA key has been loaded
  EVM: Include security.apparmor in EVM measurements
  ima: call ima_file_free() prior to calling fasync
  integrity: use kernel_read_file_from_path() to read x509 certs
  ima: always measure and audit files in policy
  ima: don't remove the securityfs policy file
  vfs: fix mounting a filesystem with i_version
2017-11-13 10:41:25 -08:00
Thiago Jung Bauermann e5729f86a2 ima: Remove redundant conditional operator
A non-zero value is converted to 1 when assigned to a bool variable, so the
conditional operator in is_ima_appraise_enabled is redundant.

The value of a comparison operator is either 1 or 0 so the conditional
operator in ima_inode_setxattr is redundant as well.

Confirmed that the patch is correct by comparing the object file from
before and after the patch. They are identical.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-11-08 15:16:36 -05:00
Thomas Meyer 39adb92598 ima: Fix bool initialization/comparison
Bool initializations should use true and false. Bool tests don't need
comparisons.

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-11-08 15:16:36 -05:00
Bruno E. O. Meneguele 7c9bc0983f ima: check signature enforcement against cmdline param instead of CONFIG
When the user requests MODULE_CHECK policy and its kernel is compiled
with CONFIG_MODULE_SIG_FORCE not set, all modules would not load, just
those loaded in initram time. One option the user would have would be
set a kernel cmdline param (module.sig_enforce) to true, but the IMA
module check code doesn't rely on this value, it checks just
CONFIG_MODULE_SIG_FORCE.

This patch solves this problem checking for the exported value of
module.sig_enforce cmdline param intead of CONFIG_MODULE_SIG_FORCE,
which holds the effective value (CONFIG || param).

Signed-off-by: Bruno E. O. Meneguele <brdeoliv@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-11-08 15:16:36 -05:00
Boshi Wang ebe7c0a7be ima: fix hash algorithm initialization
The hash_setup function always sets the hash_setup_done flag, even
when the hash algorithm is invalid.  This prevents the default hash
algorithm defined as CONFIG_IMA_DEFAULT_HASH from being used.

This patch sets hash_setup_done flag only for valid hash algorithms.

Fixes: e7a2ad7eb6 "ima: enable support for larger default filedata hash
	algorithms"
Signed-off-by: Boshi Wang <wangboshi@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-11-08 15:16:36 -05:00
Christoph Hellwig a7d3d0392a integrity: use kernel_read_file_from_path() to read x509 certs
The CONFIG_IMA_LOAD_X509 and CONFIG_EVM_LOAD_X509 options permit
loading x509 signed certificates onto the trusted keyrings without
verifying the x509 certificate file's signature.

This patch replaces the call to the integrity_read_file() specific
function with the common kernel_read_file_from_path() function.
To avoid verifying the file signature, this patch defines
READING_X509_CERTFICATE.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-11-08 15:16:36 -05:00
Mimi Zohar f3cc6b25dc 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>
2017-11-08 15:16:36 -05:00
Mimi Zohar 2068626d13 ima: don't remove the securityfs policy file
The securityfs policy file is removed unless additional rules can be
appended to the IMA policy (CONFIG_IMA_WRITE_POLICY), regardless as
to whether the policy is configured so that it can be displayed.

This patch changes this behavior, removing the securityfs policy file,
only if CONFIG_IMA_READ_POLICY is also not enabled.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-11-08 15:16:36 -05:00
Gilad Ben-Yossef 46f1414c8a ima: move to generic async completion
ima starts several async crypto ops and  waits for their completions.
Move it over to generic code doing the same.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-11-03 22:11:21 +08:00
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00
Linus Torvalds e24dd9ee53 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security layer updates from James Morris:

 - a major update for AppArmor. From JJ:

     * several bug fixes and cleanups

     * the patch to add symlink support to securityfs that was floated
       on the list earlier and the apparmorfs changes that make use of
       securityfs symlinks

     * it introduces the domain labeling base code that Ubuntu has been
       carrying for several years, with several cleanups applied. And it
       converts the current mediation over to using the domain labeling
       base, which brings domain stacking support with it. This finally
       will bring the base upstream code in line with Ubuntu and provide
       a base to upstream the new feature work that Ubuntu carries.

     * This does _not_ contain any of the newer apparmor mediation
       features/controls (mount, signals, network, keys, ...) that
       Ubuntu is currently carrying, all of which will be RFC'd on top
       of this.

 - Notable also is the Infiniband work in SELinux, and the new file:map
   permission. From Paul:

      "While we're down to 21 patches for v4.13 (it was 31 for v4.12),
       the diffstat jumps up tremendously with over 2k of line changes.

       Almost all of these changes are the SELinux/IB work done by
       Daniel Jurgens; some other noteworthy changes include a NFS v4.2
       labeling fix, a new file:map permission, and reporting of policy
       capabilities on policy load"

   There's also now genfscon labeling support for tracefs, which was
   lost in v4.1 with the separation from debugfs.

 - Smack incorporates a safer socket check in file_receive, and adds a
   cap_capable call in privilege check.

 - TPM as usual has a bunch of fixes and enhancements.

 - Multiple calls to security_add_hooks() can now be made for the same
   LSM, to allow LSMs to have hook declarations across multiple files.

 - IMA now supports different "ima_appraise=" modes (eg. log, fix) from
   the boot command line.

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (126 commits)
  apparmor: put back designators in struct initialisers
  seccomp: Switch from atomic_t to recount_t
  seccomp: Adjust selftests to avoid double-join
  seccomp: Clean up core dump logic
  IMA: update IMA policy documentation to include pcr= option
  ima: Log the same audit cause whenever a file has no signature
  ima: Simplify policy_func_show.
  integrity: Small code improvements
  ima: fix get_binary_runtime_size()
  ima: use ima_parse_buf() to parse template data
  ima: use ima_parse_buf() to parse measurements headers
  ima: introduce ima_parse_buf()
  ima: Add cgroups2 to the defaults list
  ima: use memdup_user_nul
  ima: fix up #endif comments
  IMA: Correct Kconfig dependencies for hash selection
  ima: define is_ima_appraise_enabled()
  ima: define Kconfig IMA_APPRAISE_BOOTPARAM option
  ima: define a set of appraisal rules requiring file signatures
  ima: extend the "ima_policy" boot command line to support multiple policies
  ...
2017-07-05 11:26:35 -07:00
Thiago Jung Bauermann 915d9d255d ima: Log the same audit cause whenever a file has no signature
If the file doesn't have an xattr, ima_appraise_measurement sets cause to
"missing-hash" while if there's an xattr but it's a digest instead of a
signature it sets cause to "IMA-signature-required".

Fix it by setting cause to "IMA-signature-required" in both cases.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-06-21 14:37:12 -04:00
Thiago Jung Bauermann 2663218ba6 ima: Simplify policy_func_show.
If the func_tokens array uses the same indices as enum ima_hooks,
policy_func_show can be a lot simpler, and the func_* enum becomes
unnecessary.

Also, if we use the same macro trick used by kernel_read_file_id_str we can
use one hooks list for both the enum and the string array, making sure they
are always in sync (suggested by Mimi Zohar).

Finally, by using the printf pattern for the function token directly
instead of using the pt macro we can simplify policy_func_show even further
and avoid needing a temporary buffer.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-06-21 14:37:12 -04:00
Thiago Jung Bauermann bb543e3959 integrity: Small code improvements
These changes are too small to warrant their own patches:

The keyid and sig_size members of struct signature_v2_hdr are in BE format,
so use a type that makes this assumption explicit. Also, use beXX_to_cpu
instead of __beXX_to_cpu to read them.

Change integrity_kernel_read to take a void * buffer instead of char *
buffer, so that callers don't have to use a cast if they provide a buffer
that isn't a char *.

Add missing #endif comment in ima.h pointing out which macro it refers to.

Add missing fall through comment in ima_appraise.c.

Constify mask_tokens and func_tokens arrays.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-06-21 14:37:12 -04:00
Roberto Sassu e4586c79d4 ima: fix get_binary_runtime_size()
Remove '+ 1' from 'size += strlen(entry->template_desc->name) + 1;',
as the template name is sent to userspace without the '\0' character.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-06-21 14:37:12 -04:00
Roberto Sassu 28a8dc4127 ima: use ima_parse_buf() to parse template data
The binary_field_data structure definition has been removed from
ima_restore_template_data(). The lengths and data pointers are directly
stored into the template_data array of the ima_template_entry structure.
For template data, both the number of fields and buffer end checks can
be done, as these information are known (respectively from the template
descriptor, and from the measurement header field).

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-06-21 14:37:12 -04:00
Roberto Sassu 47fdee60b4 ima: use ima_parse_buf() to parse measurements headers
The binary_hdr_v1 and binary_data_v1 structures defined in
ima_restore_measurement_list() have been replaced with an array of four
ima_field_data structures where pcr, digest, template name and
template data lengths and pointers are stored.

The length of pcr and digest in the ima_field_data array and the bits
in the bitmap are set before ima_parse_buf() is called. The ENFORCE_FIELDS
bit is set for all entries except the last one (there is still data to
parse), and ENFORCE_BUFEND is set only for the last entry.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-06-21 14:37:12 -04:00
Roberto Sassu b17fd9ecf8 ima: introduce ima_parse_buf()
ima_parse_buf() takes as input the buffer start and end pointers, and
stores the result in a static array of ima_field_data structures,
where the len field contains the length parsed from the buffer, and
the data field contains the address of the buffer just after the length.
Optionally, the function returns the current value of the buffer pointer
and the number of array elements written.

A bitmap has been added as parameter of ima_parse_buf() to handle
the cases where the length is not prepended to data. Each bit corresponds
to an element of the ima_field_data array. If a bit is set, the length
is not parsed from the buffer, but is read from the corresponding element
of the array (the length must be set before calling the function).

ima_parse_buf() can perform three checks upon request by callers,
depending on the enforce mask passed to it:

- ENFORCE_FIELDS: matching of number of fields (length-data combination)
  - there must be enough data in the buffer to parse the number of fields
    requested (output: current value of buffer pointer)
- ENFORCE_BUFEND: matching of buffer end
  - the ima_field_data array must be large enough to contain lengths and
    data pointers for the amount of data requested (output: number
    of fields written)
- ENFORCE_FIELDS | ENFORCE_BUFEND: matching of both

Use cases

- measurement entry header: ENFORCE_FIELDS | ENFORCE_BUFEND
  - four fields must be parsed: pcr, digest, template name, template data
  - ENFORCE_BUFEND is enforced only for the last measurement entry
- template digest (Crypto Agile): ENFORCE_BUFEND
  - since only the total template digest length is known, the function
    parses length-data combinations until the buffer end is reached
- template data: ENFORCE_FIELDS | ENFORCE_BUFEND
  - since the number of fields and the total template data length
    are known, the function can perform both checks

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-06-21 14:37:12 -04:00
Laura Abbott 82e3bb4d44 ima: Add cgroups2 to the defaults list
cgroups2 is beginning to show up in wider usage. Add it to the default
nomeasure/noappraise list like other filesystems.

Signed-off-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-06-21 14:37:12 -04:00
Geliang Tang b4e280304d ima: use memdup_user_nul
Use memdup_user_nul() helper instead of open-coding to simplify the
code.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-06-21 14:37:12 -04:00
Tycho Andersen 5d659f286d ima: fix up #endif comments
While reading the code, I noticed that these #endif comments don't match
how they're actually nested. This patch fixes that.

Signed-off-by: Tycho Andersen <tycho@docker.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-06-21 14:37:12 -04:00
Ben Hutchings 38d192684e IMA: Correct Kconfig dependencies for hash selection
IMA uses the hash algorithm too early to be able to use a module.
Require the selected hash algorithm to be built-in.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-06-21 14:37:12 -04:00