Commit Graph

474 Commits

Author SHA1 Message Date
Mimi Zohar
1a9430db28 ima: cleanup the match_token policy code
Start the policy_tokens and the associated enumeration from zero,
simplifying the pt macro.

Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-17 16:31:28 -08:00
James Morris
0db51ef26e Merge tag 'tpmdd-next-20181217' of git://git.infradead.org/users/jjs/linux-tpmdd into next-tpm
tpmdd updates for Linux v4.21

From Jarkko:

v4.21 updates:

* Support for partial reads of /dev/tpm0.
* Clean up for TPM 1.x code: move the commands to tpm1-cmd.c and make
  everything to use the same data structure for building TPM commands
  i.e. struct tpm_buf.
2018-12-17 11:31:58 -08:00
James Morris
5580b4a1a8 Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity into next-integrity
From Mimi:

In Linux 4.19, a new LSM hook named security_kernel_load_data was
upstreamed, allowing LSMs and IMA to prevent the kexec_load
syscall.  Different signature verification methods exist for verifying
the kexec'ed kernel image.  This pull request adds additional support
in IMA to prevent loading unsigned kernel images via the kexec_load
syscall, independently of the IMA policy rules, based on the runtime
"secure boot" flag.  An initial IMA kselftest is included.

In addition, this pull request defines a new, separate keyring named
".platform" for storing the preboot/firmware keys needed for verifying
the kexec'ed kernel image's signature and includes the associated IMA
kexec usage of the ".platform" keyring.

(David Howell's and Josh Boyer's patches for reading the
preboot/firmware keys, which were previously posted for a different
use case scenario, are included here.)
2018-12-17 11:26:46 -08:00
Nikolay Borisov
eed9de3b4f ima: Use inode_is_open_for_write
Use the aptly named function rather than open coding the check. No
functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2018-12-12 22:09:34 -05:00
Nayna Jain
d7cecb676d ima: Support platform keyring for kernel appraisal
On secure boot enabled systems, the bootloader verifies the kernel
image and possibly the initramfs signatures based on a set of keys. A
soft reboot(kexec) of the system, with the same kernel image and
initramfs, requires access to the original keys to verify the
signatures.

This patch allows IMA-appraisal access to those original keys, now
loaded on the platform keyring, needed for verifying the kernel image
and initramfs signatures.

[zohar@linux.ibm.com: only use platform keyring if it's enabled (Thiago)]
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: James Morris <james.morris@microsoft.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2018-12-12 22:09:33 -05:00
Paul Gortmaker
876979c930 security: audit and remove any unnecessary uses of module.h
Historically a lot of these existed because we did not have
a distinction between what was modular code and what was providing
support to modules via EXPORT_SYMBOL and friends.  That changed
when we forked out support for the latter into the export.h file.
This means we should be able to reduce the usage of module.h
in code that is obj-y Makefile or bool Kconfig.

The advantage in removing such instances is that module.h itself
sources about 15 other headers; adding significantly to what we feed
cpp, and it can obscure what headers we are effectively using.

Since module.h might have been the implicit source for init.h
(for __init) and for export.h (for EXPORT_SYMBOL) we consider each
instance for the presence of either and replace as needed.

Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: John Johansen <john.johansen@canonical.com>
Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: linux-security-module@vger.kernel.org
Cc: linux-integrity@vger.kernel.org
Cc: keyrings@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
2018-12-12 14:58:51 -08:00
Paul Gortmaker
4f83d5ea64 security: integrity: make ima_main explicitly non-modular
The Makefile/Kconfig entry controlling compilation of this code is:

obj-$(CONFIG_IMA) += ima.o
ima-y := ima_fs.o ima_queue.o ima_init.o ima_main.o ima_crypto.o ima_api.o \
         ima_policy.o ima_template.o ima_template_lib.o

security/integrity/ima/Kconfig:config IMA
security/integrity/ima/Kconfig- bool "Integrity Measurement Architecture(IMA)"

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

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

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

Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: linux-ima-devel@lists.sourceforge.net
Cc: linux-security-module@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
2018-12-12 14:58:50 -08:00
Mimi Zohar
060190fbe6 ima: don't measure/appraise files on efivarfs
Update the builtin IMA policies specified on the boot command line
(eg. ima_policy="tcb|appraise_tcb") to permit accessing efivar files.

Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2018-12-11 07:19:46 -05:00
Eric Richter
d958083a8f x86/ima: define arch_get_ima_policy() for x86
On x86, there are two methods of verifying a kexec'ed kernel image
signature being loaded via the kexec_file_load syscall - an architecture
specific implementaton or a IMA KEXEC_KERNEL_CHECK appraisal rule. Neither
of these methods verify the kexec'ed kernel image signature being loaded
via the kexec_load syscall.

Secure boot enabled systems require kexec images to be signed. Therefore,
this patch loads an IMA KEXEC_KERNEL_CHECK policy rule on secure boot
enabled systems not configured with CONFIG_KEXEC_VERIFY_SIG enabled.

When IMA_APPRAISE_BOOTPARAM is configured, different IMA appraise modes
(eg. fix, log) can be specified on the boot command line, allowing unsigned
or invalidly signed kernel images to be kexec'ed. This patch permits
enabling IMA_APPRAISE_BOOTPARAM or IMA_ARCH_POLICY, but not both.

Signed-off-by: Eric Richter <erichte@linux.ibm.com>
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2018-12-11 07:13:41 -05:00
Nayna Jain
6191706246 ima: add support for arch specific policies
Builtin IMA policies can be enabled on the boot command line, and replaced
with a custom policy, normally during early boot in the initramfs. Build
time IMA policy rules were recently added. These rules are automatically
enabled on boot and persist after loading a custom policy.

There is a need for yet another type of policy, an architecture specific
policy, which is derived at runtime during kernel boot, based on the
runtime secure boot flags.  Like the build time policy rules, these rules
persist after loading a custom policy.

This patch adds support for loading an architecture specific IMA policy.

Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Co-Developed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2018-12-11 07:13:40 -05:00
Nayna Jain
c52657d93b ima: refactor ima_init_policy()
This patch removes the code duplication in ima_init_policy() by defining
a new function named add_rules(). The new function adds the rules to the
initial IMA policy, the custom policy or both based on the policy mask
(IMA_DEFAULT_POLICY, IMA_CUSTOM_POLICY).

Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2018-12-11 07:13:39 -05:00
Nayna Jain
b5ca117365 ima: prevent kexec_load syscall based on runtime secureboot flag
When CONFIG_KEXEC_VERIFY_SIG is enabled, the kexec_file_load syscall
requires the kexec'd kernel image to be signed. Distros are concerned
about totally disabling the kexec_load syscall. As a compromise, the
kexec_load syscall will only be disabled when CONFIG_KEXEC_VERIFY_SIG
is configured and the system is booted with secureboot enabled.

This patch disables the kexec_load syscall only for systems booted with
secureboot enabled.

[zohar@linux.ibm.com: add missing mesage on kexec_load failure]
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2018-12-11 07:10:33 -05:00
Paul Moore
2a1fe215e7 audit: use current whenever possible
There are many places, notably audit_log_task_info() and
audit_log_exit(), that take task_struct pointers but in reality they
are always working on the current task.  This patch eliminates the
task_struct arguments and uses current directly which allows a number
of cleanups as well.

Acked-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-11-26 18:41:21 -05:00
Tomas Winkler
95adc6b410 tpm: use u32 instead of int for PCR index
The TPM specs defines PCR index as a positive number, and there is
no reason to use a signed number. It is also a possible security
issue as currently no functions check for a negative index,
which may become a large number when converted to u32.

Adjust the API to use u32 instead of int in all PCR related
functions.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
2018-11-13 13:46:31 +02:00
Goldwyn Rodrigues
a408e4a86b ima: open a new file instance if no read permissions
Open a new file instance as opposed to changing file->f_mode when
the file is not readable.  This is done to accomodate overlayfs
stacked file operations change.  The real struct file is hidden
behind the overlays struct file.  So, any file->f_mode manipulations are
not reflected on the real struct file.  Open the file again in read mode
if original file cannot be read, read and calculate the hash.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: stable@vger.kernel.org (linux-4.19)
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2018-10-10 15:18:00 -04:00
Eric Biggers
1e4c8dafbb ima: fix showing large 'violations' or 'runtime_measurements_count'
The 12 character temporary buffer is not necessarily long enough to hold
a 'long' value.  Increase it.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2018-10-10 12:56:16 -04:00
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
f91e654474 Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull integrity updates from James Morris:
 "This adds support for EVM signatures based on larger digests, contains
  a new audit record AUDIT_INTEGRITY_POLICY_RULE to differentiate the
  IMA policy rules from the IMA-audit messages, addresses two deadlocks
  due to either loading or searching for crypto algorithms, and cleans
  up the audit messages"

* 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  EVM: fix return value check in evm_write_xattrs()
  integrity: prevent deadlock during digsig verification.
  evm: Allow non-SHA1 digital signatures
  evm: Don't deadlock if a crypto algorithm is unavailable
  integrity: silence warning when CONFIG_SECURITYFS is not enabled
  ima: Differentiate auditing policy rules from "audit" actions
  ima: Do not audit if CONFIG_INTEGRITY_AUDIT is not set
  ima: Use audit_log_format() rather than audit_log_string()
  ima: Call audit_log_string() rather than logging it untrusted
2018-08-15 22:54:12 -07:00
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
Stefan Berger
dba31ee759 ima: Differentiate auditing policy rules from "audit" actions
The AUDIT_INTEGRITY_RULE is used for auditing IMA policy rules and
the IMA "audit" policy action.  This patch defines
AUDIT_INTEGRITY_POLICY_RULE to reflect the IMA policy rules.

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

type=UNKNOWN[1807] msg=audit(1527888965.738:320): action=audit \
  func=MMAP_CHECK mask=MAY_EXEC res=1
type=UNKNOWN[1807] msg=audit(1527888965.738:320): action=audit \
  func=FILE_CHECK mask=MAY_READ res=1
type=SYSCALL msg=audit(1527888965.738:320): arch=c000003e syscall=1 \
  success=yes exit=17 a0=1 a1=55bcfcca9030 a2=11 a3=7fcc1b55fb38 \
  items=0 ppid=1567 pid=1601 auid=0 uid=0 gid=0 euid=0 suid=0 \
  fsuid=0 egid=0 sgid=0 fsgid=0 tty=tty2 ses=2 comm="echo" \
  exe="/usr/bin/echo" \
  subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-07-18 07:27:22 -04:00
Stefan Berger
2afd020aae ima: Do not audit if CONFIG_INTEGRITY_AUDIT is not set
If Integrity is not auditing, IMA shouldn't audit, either.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-07-18 07:27:22 -04:00
Stefan Berger
3d2859d5d4 ima: Use audit_log_format() rather than audit_log_string()
Remove the usage of audit_log_string() and replace it with
audit_log_format().

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Suggested-by: Steve Grubb <sgrubb@redhat.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-07-18 07:27:22 -04:00
Stefan Berger
8a3bcaf6ec ima: Call audit_log_string() rather than logging it untrusted
The parameters passed to this logging function are all provided by
a privileged user and therefore we can call audit_log_string()
rather than audit_log_untrustedstring().

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Suggested-by: Steve Grubb <sgrubb@redhat.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-07-18 07:27:22 -04:00
Mimi Zohar
4f0496d8ff ima: based on policy warn about loading firmware (pre-allocated buffer)
Some systems are memory constrained but they need to load very large
firmwares.  The firmware subsystem allows drivers to request this
firmware be loaded from the filesystem, but this requires that the
entire firmware be loaded into kernel memory first before it's provided
to the driver.  This can lead to a situation where we map the firmware
twice, once to load the firmware into kernel memory and once to copy the
firmware into the final resting place.

To resolve this problem, commit a098ecd2fa ("firmware: support loading
into a pre-allocated buffer") introduced request_firmware_into_buf() API
that allows drivers to request firmware be loaded directly into a
pre-allocated buffer.

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

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

[1] https://lkml.org/lkml/2018/7/10/56

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
2018-07-16 12:31:57 -07:00
Mimi Zohar
c77b8cdf74 module: replace the existing LSM hook in init_module
Both the init_module and finit_module syscalls call either directly
or indirectly the security_kernel_read_file LSM hook.  This patch
replaces the direct call in init_module with a call to the new
security_kernel_load_data hook and makes the corresponding changes
in SELinux, LoadPin, and IMA.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
2018-07-16 12:31:57 -07:00
Mimi Zohar
ef96837b0d ima: add build time policy
IMA by default does not measure, appraise or audit files, but can be
enabled at runtime by specifying a builtin policy on the boot command line
or by loading a custom policy.

This patch defines a build time policy, which verifies kernel modules,
firmware, kexec image, and/or the IMA policy signatures.  This build time
policy is automatically enabled at runtime and persists after loading a
custom policy.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
2018-07-16 12:31:57 -07:00
Mimi Zohar
fed2512a7c ima: based on policy require signed firmware (sysfs fallback)
With an IMA policy requiring signed firmware, this patch prevents
the sysfs fallback method of loading firmware.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Matthew Garrett <mjg59@google.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
2018-07-16 12:31:57 -07:00
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
Linus Torvalds
00d535a386 Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull integrity updates from James Morris:
 "From Mimi:

   - add run time support for specifying additional security xattrs
     included in the security.evm HMAC/signature

   - some code clean up and bug fixes"

* 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  EVM: unlock on error path in evm_read_xattrs()
  EVM: prevent array underflow in evm_write_xattrs()
  EVM: Fix null dereference on xattr when xattr fails to allocate
  EVM: fix memory leak of temporary buffer 'temp'
  IMA: use list_splice_tail_init_rcu() instead of its open coded variant
  ima: use match_string() helper
  ima: fix updating the ima_appraise flag
  ima: based on policy verify firmware signatures (pre-allocated buffer)
  ima: define a new policy condition based on the filesystem name
  EVM: Allow runtime modification of the set of verified xattrs
  EVM: turn evm_config_xattrnames into a list
  integrity: Add an integrity directory in securityfs
  ima: Remove unused variable ima_initialized
  ima: Unify logging
  ima: Reflect correct permissions for policy
2018-06-07 15:40:37 -07:00
Petko Manolov
53b626f903 IMA: use list_splice_tail_init_rcu() instead of its open coded variant
Use list_splice_tail_init_rcu() to extend the existing custom IMA policy
with additional IMA policy rules.

Signed-off-by: Petko Manolov <petko.manolov@konsulko.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-05-31 10:13:22 -04:00
Yisheng Xie
b4df86085a ima: use match_string() helper
match_string() returns the index of an array for a matching string,
which can be used intead of open coded variant.

Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-05-31 10:11:58 -04:00
Mimi Zohar
6f0911a666 ima: fix updating the ima_appraise flag
As IMA policy rules are added, a mask of the type of rule (eg. kernel
modules, firmware, IMA policy) is updated.  Unlike custom IMA policy
rules, which replace the original builtin policy rules and update the
mask, the builtin "secure_boot" policy rules were loaded, but did not
update the mask.

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

Fixes: 503ceaef8e ("ima: define a set of appraisal rules requiring file signatures")
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-05-22 13:16:42 -04:00
Mimi Zohar
fd90bc559b ima: based on policy verify firmware signatures (pre-allocated buffer)
Don't differentiate, for now, between kernel_read_file_id READING_FIRMWARE
and READING_FIRMWARE_PREALLOC_BUFFER enumerations.

Fixes: a098ecd firmware: support loading into a pre-allocated buffer (since 4.8)
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Serge E. Hallyn <serge@hallyn.com>
Cc: Stephen Boyd <stephen.boyd@linaro.org>
2018-05-22 07:34:47 -04:00
Mimi Zohar
f1b08bbcbd ima: define a new policy condition based on the filesystem name
If/when file data signatures are distributed with the file data, this
patch will not be needed.  In the current environment where only some
files are signed, the ability to differentiate between file systems is
needed.  Some file systems consider the file system magic number
internal to the file system.

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

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

appraise func=BPRM_CHECK fsname=rootfs appraise_type=imasig
appraise func=FILE_MMAP fsname=rootfs appraise_type=imasig

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Theodore Ts'o <tytso@mit.edu>
2018-05-22 07:33:53 -04:00
Matthew Garrett
0c343af806 integrity: Add an integrity directory in securityfs
We want to add additional evm control nodes, and it'd be preferable not
to clutter up the securityfs root directory any further. Create a new
integrity directory, move the ima directory into it, create an evm
directory for the evm attribute and add compatibility symlinks.

Signed-off-by: Matthew Garrett <mjg59@google.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-05-17 08:03:07 -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
Petr Vorel
de636769c8 ima: Unify logging
Define pr_fmt everywhere.

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

Changelog:
Previous pr_fmt definition was too late and caused problems in powerpc
allyesconfg build.
2018-05-17 07:49:12 -04:00
Petr Vorel
ffb122de9a ima: Reflect correct permissions for policy
Kernel configured as CONFIG_IMA_READ_POLICY=y && CONFIG_IMA_WRITE_POLICY=n
keeps 0600 mode after loading policy. Remove write permission to state
that policy file no longer be written.

Signed-off-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-05-17 07:47:17 -04:00
Richard Guy Briggs
cdfb6b341f audit: use inline function to get audit context
Recognizing that the audit context is an internal audit value, use an
access function to retrieve the audit context pointer for the task
rather than reaching directly into the task struct to get it.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: merge fuzz in auditsc.c and selinuxfs.c, checkpatch.pl fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-05-14 17:24:18 -04:00
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