Commit Graph

109 Commits

Author SHA1 Message Date
Linus Torvalds aefcf2f4b5 Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull kernel lockdown mode from James Morris:
 "This is the latest iteration of the kernel lockdown patchset, from
  Matthew Garrett, David Howells and others.

  From the original description:

    This patchset introduces an optional kernel lockdown feature,
    intended to strengthen the boundary between UID 0 and the kernel.
    When enabled, various pieces of kernel functionality are restricted.
    Applications that rely on low-level access to either hardware or the
    kernel may cease working as a result - therefore this should not be
    enabled without appropriate evaluation beforehand.

    The majority of mainstream distributions have been carrying variants
    of this patchset for many years now, so there's value in providing a
    doesn't meet every distribution requirement, but gets us much closer
    to not requiring external patches.

  There are two major changes since this was last proposed for mainline:

   - Separating lockdown from EFI secure boot. Background discussion is
     covered here: https://lwn.net/Articles/751061/

   -  Implementation as an LSM, with a default stackable lockdown LSM
      module. This allows the lockdown feature to be policy-driven,
      rather than encoding an implicit policy within the mechanism.

  The new locked_down LSM hook is provided to allow LSMs to make a
  policy decision around whether kernel functionality that would allow
  tampering with or examining the runtime state of the kernel should be
  permitted.

  The included lockdown LSM provides an implementation with a simple
  policy intended for general purpose use. This policy provides a coarse
  level of granularity, controllable via the kernel command line:

    lockdown={integrity|confidentiality}

  Enable the kernel lockdown feature. If set to integrity, kernel features
  that allow userland to modify the running kernel are disabled. If set to
  confidentiality, kernel features that allow userland to extract
  confidential information from the kernel are also disabled.

  This may also be controlled via /sys/kernel/security/lockdown and
  overriden by kernel configuration.

  New or existing LSMs may implement finer-grained controls of the
  lockdown features. Refer to the lockdown_reason documentation in
  include/linux/security.h for details.

  The lockdown feature has had signficant design feedback and review
  across many subsystems. This code has been in linux-next for some
  weeks, with a few fixes applied along the way.

  Stephen Rothwell noted that commit 9d1f8be5cf ("bpf: Restrict bpf
  when kernel lockdown is in confidentiality mode") is missing a
  Signed-off-by from its author. Matthew responded that he is providing
  this under category (c) of the DCO"

* 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (31 commits)
  kexec: Fix file verification on S390
  security: constify some arrays in lockdown LSM
  lockdown: Print current->comm in restriction messages
  efi: Restrict efivar_ssdt_load when the kernel is locked down
  tracefs: Restrict tracefs when the kernel is locked down
  debugfs: Restrict debugfs when the kernel is locked down
  kexec: Allow kexec_file() with appropriate IMA policy when locked down
  lockdown: Lock down perf when in confidentiality mode
  bpf: Restrict bpf when kernel lockdown is in confidentiality mode
  lockdown: Lock down tracing and perf kprobes when in confidentiality mode
  lockdown: Lock down /proc/kcore
  x86/mmiotrace: Lock down the testmmiotrace module
  lockdown: Lock down module params that specify hardware parameters (eg. ioport)
  lockdown: Lock down TIOCSSERIAL
  lockdown: Prohibit PCMCIA CIS storage when the kernel is locked down
  acpi: Disable ACPI table override if the kernel is locked down
  acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down
  ACPI: Limit access to custom_method when the kernel is locked down
  x86/msr: Restrict MSR access when the kernel is locked down
  x86: Lock down IO port access when the kernel is locked down
  ...
2019-09-28 08:14:15 -07:00
Matthew Garrett 29d3c1c8df kexec: Allow kexec_file() with appropriate IMA policy when locked down
Systems in lockdown mode should block the kexec of untrusted kernels.
For x86 and ARM we can ensure that a kernel is trustworthy by validating
a PE signature, but this isn't possible on other architectures. On those
platforms we can use IMA digital signatures instead. Add a function to
determine whether IMA has or will verify signatures for a given event type,
and if so permit kexec_file() even if the kernel is otherwise locked down.
This is restricted to cases where CONFIG_INTEGRITY_TRUSTED_KEYRING is set
in order to prevent an attacker from loading additional keys at runtime.

Signed-off-by: Matthew Garrett <mjg59@google.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: linux-integrity@vger.kernel.org
Signed-off-by: James Morris <jmorris@namei.org>
2019-08-19 21:54:16 -07:00
Thiago Jung Bauermann e5092255bb ima: Store the measurement again when appraising a modsig
If the IMA template contains the "modsig" or "d-modsig" field, then the
modsig should be added to the measurement list when the file is appraised.

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

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

Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-08-05 18:40:26 -04:00
Thiago Jung Bauermann 3878d505aa ima: Define ima-modsig template
Define new "d-modsig" template field which holds the digest that is
expected to match the one contained in the modsig, and also new "modsig"
template field which holds the appended file signature.

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

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

Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-08-05 18:40:25 -04:00
Thiago Jung Bauermann 15588227e0 ima: Collect modsig
Obtain the modsig and calculate its corresponding hash in
ima_collect_measurement().

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-08-05 18:40:24 -04:00
Thiago Jung Bauermann 39b0709636 ima: Implement support for module-style appended signatures
Implement the appraise_type=imasig|modsig option, allowing IMA to read and
verify modsig signatures.

In case a file has both an xattr signature and an appended modsig, IMA will
only use the appended signature if the key used by the xattr signature
isn't present in the IMA or platform keyring.

Because modsig verification needs to convert from an integrity keyring id
to the keyring itself, add an integrity_keyring_from_id() function in
digsig.c so that integrity_modsig_verify() can use it.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-08-05 18:40:23 -04:00
Thiago Jung Bauermann 9044d627fd ima: Add modsig appraise_type option for module-style appended signatures
Introduce the modsig keyword to the IMA policy syntax to specify that
a given hook should expect the file to have the IMA signature appended
to it. Here is how it can be used in a rule:

appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig|modsig

With this rule, IMA will accept either a signature stored in the extended
attribute or an appended signature.

For now, the rule above will behave exactly the same as if
appraise_type=imasig was specified. The actual modsig implementation
will be introduced separately.

Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-08-05 18:40:21 -04:00
Linus Torvalds 8b68150883 Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity
Pull integrity updates from Mimi Zohar:
 "Bug fixes, code clean up, and new features:

   - IMA policy rules can be defined in terms of LSM labels, making the
     IMA policy dependent on LSM policy label changes, in particular LSM
     label deletions. The new environment, in which IMA-appraisal is
     being used, frequently updates the LSM policy and permits LSM label
     deletions.

   - Prevent an mmap'ed shared file opened for write from also being
     mmap'ed execute. In the long term, making this and other similar
     changes at the VFS layer would be preferable.

   - The IMA per policy rule template format support is needed for a
     couple of new/proposed features (eg. kexec boot command line
     measurement, appended signatures, and VFS provided file hashes).

   - Other than the "boot-aggregate" record in the IMA measuremeent
     list, all other measurements are of file data. Measuring and
     storing the kexec boot command line in the IMA measurement list is
     the first buffer based measurement included in the measurement
     list"

* 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
  integrity: Introduce struct evm_xattr
  ima: Update MAX_TEMPLATE_NAME_LEN to fit largest reasonable definition
  KEXEC: Call ima_kexec_cmdline to measure the boot command line args
  IMA: Define a new template field buf
  IMA: Define a new hook to measure the kexec boot command line arguments
  IMA: support for per policy rule template formats
  integrity: Fix __integrity_init_keyring() section mismatch
  ima: Use designated initializers for struct ima_event_data
  ima: use the lsm policy update notifier
  LSM: switch to blocking policy update notifiers
  x86/ima: fix the Kconfig dependency for IMA_ARCH_POLICY
  ima: Make arch_policy_entry static
  ima: prevent a file already mmap'ed write to be mmap'ed execute
  x86/ima: check EFI SetupMode too
2019-07-08 20:28:59 -07:00
Prakhar Srivastava 86b4da8c0e IMA: Define a new template field buf
A buffer(kexec boot command line arguments) measured into IMA
measuremnt list cannot be appraised, without already being
aware of the buffer contents. Since hashes are non-reversible,
raw buffer is needed for validation or regenerating hash for
appraisal/attestation.

Add support to store/read the buffer contents in HEX.
The kexec cmdline hash is stored in the "d-ng" field of the
template data.  It can be verified using
sudo cat /sys/kernel/security/integrity/ima/ascii_runtime_measurements |
  grep  kexec-cmdline | cut -d' ' -f 6 | xxd -r -p | sha256sum

- Add two new fields to ima_event_data to hold the buf and
buf_len
- Add a new template field 'buf' to be used to store/read
the buffer data.
- Updated process_buffer_meaurement to add the buffer to
ima_event_data. process_buffer_measurement added in
"Define a new IMA hook to measure the boot command line
 arguments"
- Add a new template policy name ima-buf to represent
'd-ng|n-ng|buf'

Signed-off-by: Prakhar Srivastava <prsriva02@gmail.com>
Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-06-30 17:53:45 -04:00
Prakhar Srivastava b0935123a1 IMA: Define a new hook to measure the kexec boot command line arguments
Currently during soft reboot(kexec_file_load) boot command line
arguments are not measured. Define hooks needed to measure kexec
command line arguments during soft reboot(kexec_file_load).

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

Signed-off-by: Prakhar Srivastava <prsriva02@gmail.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-06-24 08:29:57 -04:00
Matthew Garrett 19453ce0bc IMA: support for per policy rule template formats
Admins may wish to log different measurements using different IMA
templates. Add support for overriding the default template on a per-rule
basis.

Inspired-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Matthew Garrett <mjg59@google.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-06-19 18:51:01 -04:00
Janne Karhunen b169424551 ima: use the lsm policy update notifier
Don't do lazy policy updates while running the rule matching,
run the updates as they happen.

Depends on commit f242064c5df3 ("LSM: switch to blocking policy update notifiers")

Signed-off-by: Janne Karhunen <janne.karhunen@gmail.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-06-14 09:02:43 -04:00
Thomas Gleixner b886d83c5b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441
Based on 1 normalized pattern(s):

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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

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

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:37:17 +02:00
Linus Torvalds 5af7f11588 Merge branch 'next-tpm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull tpm updates from James Morris:

 - Clean up the transmission flow

   Cleaned up the whole transmission flow. Locking of the chip is now
   done in the level of tpm_try_get_ops() and tpm_put_ops() instead
   taking the chip lock inside tpm_transmit(). The nested calls inside
   tpm_transmit(), used with the resource manager, have been refactored
   out.

   Should make easier to perform more complex transactions with the TPM
   without making the subsystem a bigger mess (e.g. encrypted channel
   patches by James Bottomley).

 - PPI 1.3 support

   TPM PPI 1.3 introduces an additional optional command parameter that
   may be needed for some commands. Display the parameter if the command
   requires such a parameter. Only command 23 (SetPCRBanks) needs one.

   The PPI request file will show output like this then:

      # echo "23 16" > request
      # cat request
      23 16

      # echo "5" > request
      # cat request
      5

 - Extend all PCR banks in IMA

   Instead of static PCR banks array, the array of available PCR banks
   is now allocated dynamically. The digests sizes are determined
   dynamically using a probe PCR read without relying crypto's static
   list of hash algorithms.

   This should finally make sealing of measurements in IMA safe and
   secure.

 - TPM 2.0 selftests

   Added a test suite to tools/testing/selftests/tpm2 previously outside
   of the kernel tree: https://github.com/jsakkine-intel/tpm2-scripts

* 'next-tpm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (37 commits)
  tpm/ppi: Enable submission of optional command parameter for PPI 1.3
  tpm/ppi: Possibly show command parameter if TPM PPI 1.3 is used
  tpm/ppi: Display up to 101 operations as define for version 1.3
  tpm/ppi: rename TPM_PPI_REVISION_ID to TPM_PPI_REVISION_ID_1
  tpm/ppi: pass function revision ID to tpm_eval_dsm()
  tpm: pass an array of tpm_extend_digest structures to tpm_pcr_extend()
  KEYS: trusted: explicitly use tpm_chip structure from tpm_default_chip()
  tpm: move tpm_chip definition to include/linux/tpm.h
  tpm: retrieve digest size of unknown algorithms with PCR read
  tpm: rename and export tpm2_digest and tpm2_algorithms
  tpm: dynamically allocate the allocated_banks array
  tpm: remove @flags from tpm_transmit()
  tpm: take TPM chip power gating out of tpm_transmit()
  tpm: introduce tpm_chip_start() and tpm_chip_stop()
  tpm: remove TPM_TRANSMIT_UNLOCKED flag
  tpm: use tpm_try_get_ops() in tpm-sysfs.c.
  tpm: remove @space from tpm_transmit()
  tpm: move TPM space code out of tpm_transmit()
  tpm: move tpm_validate_commmand() to tpm2-space.c
  tpm: clean up tpm_try_transmit() error handling flow
  ...
2019-03-10 17:37:29 -07:00
Roberto Sassu 0b6cf6b97b tpm: pass an array of tpm_extend_digest structures to tpm_pcr_extend()
Currently, tpm_pcr_extend() accepts as an input only a SHA1 digest.

This patch replaces the hash parameter of tpm_pcr_extend() with an array of
tpm_digest structures, so that the caller can provide a digest for each PCR
bank currently allocated in the TPM.

tpm_pcr_extend() will not extend banks for which no digest was provided,
as it happened before this patch, but instead it requires that callers
provide the full set of digests. Since the number of digests will always be
chip->nr_allocated_banks, the count parameter has been removed.

Due to the API change, ima_pcr_extend() and pcrlock() have been modified.
Since the number of allocated banks is not known in advance, the memory for
the digests must be dynamically allocated. To avoid performance degradation
and to avoid that a PCR extend is not done due to lack of memory, the array
of tpm_digest structures is allocated by the users of the TPM driver at
initialization time.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Mimi Zohar <zohar@linux.ibm.com> (on x86 for TPM 1.2 & PTT TPM 2.0)
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
2019-02-13 09:48:52 +02:00
Richard Guy Briggs 90462a5bd3 audit: remove unused actx param from audit_rule_match
The audit_rule_match() struct audit_context *actx parameter is not used
by any in-tree consumers (selinux, apparmour, integrity, smack).

The audit context is an internal audit structure that should only be
accessed by audit accessor functions.

It was part of commit 03d37d25e0 ("LSM/Audit: Introduce generic
Audit LSM hooks") but appears to have never been used.

Remove it.

Please see the github issue
https://github.com/linux-audit/audit-kernel/issues/107

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: fixed the referenced commit title]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-01-31 23:00:15 -05:00
Eric Biggers b2724d5802 security/integrity: constify some read-only data
Constify some static data that is never modified,
so that it is placed in .rodata.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2018-10-10 12:56:15 -04:00
Linus Torvalds c715ebeb03 Merge branch 'next-tpm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull TPM updates from James Morris:

 - Migrate away from PM runtime as explicit cmdReady/goIdle transactions
   for every command is a spec requirement. PM runtime adds only a layer
   of complexity on our case.

 - tpm_tis drivers can now specify the hwrng quality.

 - TPM 2.0 code uses now tpm_buf for constructing messages. Jarkko
   thinks Tomas Winkler has done the same for TPM 1.2, and will start
   digging those changes from the patchwork in the near future.

 - Bug fixes and clean ups

* 'next-tpm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  ima: Get rid of ima_used_chip and use ima_tpm_chip != NULL instead
  ima: Use tpm_default_chip() and call TPM functions with a tpm_chip
  tpm: replace TPM_TRANSMIT_RAW with TPM_TRANSMIT_NESTED
  tpm: Convert tpm_find_get_ops() to use tpm_default_chip()
  tpm: Implement tpm_default_chip() to find a TPM chip
  tpm: rename tpm_chip_find_get() to tpm_find_get_ops()
  tpm: Allow tpm_tis drivers to set hwrng quality.
  tpm: Return the actual size when receiving an unsupported command
  tpm: separate cmd_ready/go_idle from runtime_pm
  tpm/tpm_i2c_infineon: switch to i2c_lock_bus(..., I2C_LOCK_SEGMENT)
  tpm_tis_spi: Pass the SPI IRQ down to the driver
  tpm: migrate tpm2_get_random() to use struct tpm_buf
  tpm: migrate tpm2_get_tpm_pt() to use struct tpm_buf
  tpm: migrate tpm2_probe() to use struct tpm_buf
  tpm: migrate tpm2_shutdown() to use struct tpm_buf
2018-08-15 22:51:12 -07:00
Linus Torvalds 92d4a03674 Merge branch 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris:

 - kstrdup() return value fix from Eric Biggers

 - Add new security_load_data hook to differentiate security checking of
   kernel-loaded binaries in the case of there being no associated file
   descriptor, from Mimi Zohar.

 - Add ability to IMA to specify a policy at build-time, rather than
   just via command line params or by loading a custom policy, from
   Mimi.

 - Allow IMA and LSMs to prevent sysfs firmware load fallback (e.g. if
   using signed firmware), from Mimi.

 - Allow IMA to deny loading of kexec kernel images, as they cannot be
   measured by IMA, from Mimi.

* 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  security: check for kstrdup() failure in lsm_append()
  security: export security_kernel_load_data function
  ima: based on policy warn about loading firmware (pre-allocated buffer)
  module: replace the existing LSM hook in init_module
  ima: add build time policy
  ima: based on policy require signed firmware (sysfs fallback)
  firmware: add call to LSM hook before firmware sysfs fallback
  ima: based on policy require signed kexec kernel images
  kexec: add call to LSM hook in original kexec_load syscall
  security: define new LSM hook named security_kernel_load_data
  MAINTAINERS: remove the outdated "LINUX SECURITY MODULE (LSM) FRAMEWORK" entry
2018-08-15 10:25:26 -07:00
Stefan Berger ec403d8ed0 ima: Get rid of ima_used_chip and use ima_tpm_chip != NULL instead
Get rid of ima_used_chip and use ima_tpm_chip variable instead for
determining whether to use the TPM chip.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
2018-07-28 17:03:11 +03:00
Stefan Berger 5c2a640aff ima: Use tpm_default_chip() and call TPM functions with a tpm_chip
Rather than accessing the TPM functions by passing a NULL pointer for
the tpm_chip, which causes a lookup for a suitable chip every time, get a
hold of a tpm_chip and access the TPM functions using it.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
2018-07-28 17:03:11 +03:00
Mimi Zohar 16c267aac8 ima: based on policy require signed kexec kernel images
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: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
2018-07-16 12:31:57 -07:00
Al Viro 6035a27b25 IMA: don't propagate opened through the entire thing
just check ->f_mode in ima_appraise_measurement()

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-12 10:04:19 -04:00
Petr Vorel 4ecd9934ba ima: Remove unused variable ima_initialized
Commit a756024 ("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: Petr Vorel <pvorel@suse.cz>
Reviewed-by: James Morris <james.morris@microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-05-17 08:03:06 -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
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
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
Mimi Zohar bc15ed663e ima: fix ima_d_path() possible race with rename
On failure to return a pathname from ima_d_path(), a pointer to
dname is returned, which is subsequently used in the IMA measurement
list, the IMA audit records, and other audit logging.  Saving the
pointer to dname for later use has the potential to race with rename.

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

Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
2017-01-27 14:16:02 -05:00
Mimi Zohar d68a6fe9fc ima: define a canonical binary_runtime_measurements list format
The IMA binary_runtime_measurements list is currently in platform native
format.

To allow restoring a measurement list carried across kexec with a
different endianness than the targeted kernel, this patch defines
little-endian as the canonical format.  For big endian systems wanting
to save/restore the measurement list from a system with a different
endianness, a new boot command line parameter named "ima_canonical_fmt"
is defined.

Considerations: use of the "ima_canonical_fmt" boot command line option
will break existing userspace applications on big endian systems
expecting the binary_runtime_measurements list to be in platform native
format.

Link: http://lkml.kernel.org/r/1480554346-29071-10-git-send-email-zohar@linux.vnet.ibm.com
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andreas Steffen <andreas.steffen@strongswan.org>
Cc: Josh Sklar <sklar@linux.vnet.ibm.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-20 09:48:45 -08:00
Mimi Zohar 3f23d624de ima: store the builtin/custom template definitions in a list
The builtin and single custom templates are currently stored in an
array.  In preparation for being able to restore a measurement list
containing multiple builtin/custom templates, this patch stores the
builtin and custom templates as a linked list.  This will permit
defining more than one custom template per boot.

Link: http://lkml.kernel.org/r/1480554346-29071-8-git-send-email-zohar@linux.vnet.ibm.com
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andreas Steffen <andreas.steffen@strongswan.org>
Cc: Josh Sklar <sklar@linux.vnet.ibm.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-20 09:48:45 -08:00
Mimi Zohar 7b8589cc29 ima: on soft reboot, save the measurement list
The TPM PCRs are only reset on a hard reboot.  In order to validate a
TPM's quote after a soft reboot (eg.  kexec -e), the IMA measurement
list of the running kernel must be saved and restored on boot.

This patch uses the kexec buffer passing mechanism to pass the
serialized IMA binary_runtime_measurements to the next kernel.

Link: http://lkml.kernel.org/r/1480554346-29071-7-git-send-email-zohar@linux.vnet.ibm.com
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: Andreas Steffen <andreas.steffen@strongswan.org>
Cc: Josh Sklar <sklar@linux.vnet.ibm.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-20 09:48:44 -08:00
Mimi Zohar d158847ae8 ima: maintain memory size needed for serializing the measurement list
In preparation for serializing the binary_runtime_measurements, this
patch maintains the amount of memory required.

Link: http://lkml.kernel.org/r/1480554346-29071-5-git-send-email-zohar@linux.vnet.ibm.com
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andreas Steffen <andreas.steffen@strongswan.org>
Cc: Josh Sklar <sklar@linux.vnet.ibm.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-20 09:48:44 -08:00
Mimi Zohar 94c3aac567 ima: on soft reboot, restore the measurement list
The TPM PCRs are only reset on a hard reboot.  In order to validate a
TPM's quote after a soft reboot (eg.  kexec -e), the IMA measurement
list of the running kernel must be saved and restored on boot.  This
patch restores the measurement list.

Link: http://lkml.kernel.org/r/1480554346-29071-3-git-send-email-zohar@linux.vnet.ibm.com
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andreas Steffen <andreas.steffen@strongswan.org>
Cc: Josh Sklar <sklar@linux.vnet.ibm.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-20 09:48:43 -08:00
Eric Richter 14b1da85bb ima: include pcr for each measurement log entry
The IMA measurement list entries include the Kconfig defined PCR value.
This patch defines a new ima_template_entry field for including the PCR
as specified in the policy rule.

Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-06-30 01:14:21 -04:00
Eric Richter 725de7fabb ima: extend ima_get_action() to return the policy pcr
Different policy rules may extend different PCRs. This patch retrieves
the specific PCR for the matched rule.  Subsequent patches will include
the rule specific PCR in the measurement list and extend the appropriate
PCR.

Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-06-30 01:14:20 -04:00
Al Viro 81cd8896a6 constify ima_d_path()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-03-28 00:47:52 -04:00
Mimi Zohar 19f8a84713 ima: measure and appraise the IMA policy itself
Add support for measuring and appraising the IMA policy itself.

Changelog v4:
- use braces on both if/else branches, even if single line on one of the
branches - Dmitry
- Use the id mapping - Dmitry

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Petko Manolov <petkan@mip-labs.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
2016-02-21 09:34:22 -05:00
Mimi Zohar d9ddf077bb ima: support for kexec image and initramfs
Add IMA policy support for measuring/appraising the kexec image and
initramfs. Two new IMA policy identifiers KEXEC_KERNEL_CHECK and
KEXEC_INITRAMFS_CHECK are defined.

Example policy rules:
measure func=KEXEC_KERNEL_CHECK
appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig
measure func=KEXEC_INITRAMFS_CHECK
appraise func=KEXEC_INITRAMFS_CHECK appraise_type=imasig

Moving the enumeration to the vfs layer simplified the patches, allowing
the IMA changes, for the most part, to be separated from the other
changes.  Unfortunately, passing either a kernel_read_file_id or a
ima_hooks enumeration within IMA is messy.

Option 1: duplicate kernel_read_file enumeration in ima_hooks

enum kernel_read_file_id {
	...
        READING_KEXEC_IMAGE,
        READING_KEXEC_INITRAMFS,
        READING_MAX_ID

enum ima_hooks {
	...
	KEXEC_KERNEL_CHECK
	KEXEC_INITRAMFS_CHECK

Option 2: define ima_hooks as extension of kernel_read_file
eg: enum ima_hooks {
        FILE_CHECK = READING_MAX_ID,
        MMAP_CHECK,

In order to pass both kernel_read_file_id and ima_hooks values, we
would need to specify a struct containing a union.

struct caller_id {
        union {
                enum ima_hooks func_id;
                enum kernel_read_file_id read_id;
        };
};

Option 3: incorportate the ima_hooks enumeration into kernel_read_file_id,
perhaps changing the enumeration name.

For now, duplicate the new READING_KEXEC_IMAGE/INITRAMFS in the ima_hooks.

Changelog v4:
- replaced switch statement with a kernel_read_file_id to an ima_hooks
id mapping array - Dmitry
- renamed ima_hook tokens KEXEC_CHECK and INITRAMFS_CHECK to
KEXEC_KERNEL_CHECK and KEXEC_INITRAMFS_CHECK respectively - Dave Young

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Petko Manolov <petkan@mip-labs.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Cc: Dave Young <dyoung@redhat.com>
2016-02-21 09:06:16 -05:00
Mimi Zohar c6af8efe97 ima: remove firmware and module specific cached status info
Each time a file is read by the kernel, the file should be re-measured and
the file signature re-appraised, based on policy.  As there is no need to
preserve the status information, this patch replaces the firmware and
module specific cache status with a generic one named read_file.

This change simplifies adding support for other files read by the kernel.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Petko Manolov <petkan@mip-labs.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
2016-02-21 09:06:13 -05:00
Mimi Zohar cf22221786 ima: define a new hook to measure and appraise a file already in memory
This patch defines a new IMA hook ima_post_read_file() for measuring
and appraising files read by the kernel. The caller loads the file into
memory before calling this function, which calculates the hash followed by
the normal IMA policy based processing.

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

v1:
- split patch

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
2016-02-20 22:35:08 -05:00
Dmitry Kasatkin 11d7646df8 ima: provide buffer hash calculation function
This patch provides convenient buffer hash calculation function.

Changelog v3:
- fix while hash calculation - Dmitry
v1:
- rewrite to support loff_t sized buffers - Mimi
  (based on Fenguang Wu's testing)

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-02-18 17:14:28 -05:00
Mimi Zohar 4ad87a3d74 ima: use "ima_hooks" enum as function argument
Cleanup the function arguments by using "ima_hooks" enumerator as needed.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Petko Manolov <petkan@mip-labs.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
2016-02-18 17:13:58 -05:00
Dmitry Kasatkin 1525b06d99 ima: separate 'security.ima' reading functionality from collect
Instead of passing pointers to pointers to ima_collect_measurent() to
read and return the 'security.ima' xattr value, this patch moves the
functionality to the calling process_measurement() to directly read
the xattr and pass only the hash algo to the ima_collect_measurement().

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-02-18 17:13:32 -05:00
Sasha Levin 0112721df4 IMA: policy can be updated zero times
Commit "IMA: policy can now be updated multiple times" assumed that the
policy would be updated at least once.

If there are zero updates, the temporary list head object will get added
to the policy list, and later dereferenced as an IMA policy object, which
means that invalid memory will be accessed.

Changelog:
- Move list_empty() test to ima_release_policy(), before audit msg - Mimi

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-12-24 18:56:45 -05:00
Petko Manolov 80eae209d6 IMA: allow reading back the current IMA policy
It is often useful to be able to read back the IMA policy.  It is
even more important after introducing CONFIG_IMA_WRITE_POLICY.
This option allows the root user to see the current policy rules.

Signed-off-by: Zbigniew Jasinski <z.jasinski@samsung.com>
Signed-off-by: Petko Manolov <petkan@mip-labs.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-12-15 10:01:43 -05:00
Dmitry Kasatkin f4dc37785e integrity: define '.evm' as a builtin 'trusted' keyring
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: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-11-23 14:30:02 -05:00
Mimi Zohar 45b26133b9 ima: fix ima_show_template_data_ascii()
This patch fixes a bug introduced in "4d7aeee ima: define new template
ima-ng and template fields d-ng and n-ng".

Changelog:
- change int to uint32 (Roberto Sassu's suggestion)

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Roberto Sassu <rsassu@suse.de>
Cc: stable@vger.kernel.org # 3.13
2015-06-16 08:18:21 -04:00
Roberto Sassu 8d94eb9b5c ima: pass iint to ima_add_violation()
This patch adds the iint associated to the current inode as a new
parameter of ima_add_violation(). The passed iint is always not NULL
if a violation is detected. This modification will be used to determine
the inode for which there is a violation.

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

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

Signed-off-by: Roberto Sassu <rsassu@suse.de>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-05-21 13:59:29 -04:00
Roberto Sassu 23b5741932 ima: wrap event related data to the new ima_event_data structure
All event related data has been wrapped into the new 'ima_event_data'
structure. The main benefit of this patch is that a new information
can be made available to template fields initialization functions
by simply adding a new field to the new structure instead of modifying
the definition of those functions.

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

Signed-off-by: Roberto Sassu <rsassu@suse.de>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-05-21 13:59:28 -04:00