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Kdump kernel doesn't need IMA to do integrity measurement.
Hence the measurement list in 1st kernel doesn't need to be copied to
kdump kernel.
Here skip allocating buffer for measurement list copying if loading
kdump kernel. Then there won't be the later handling related to
ima_kexec_buffer.
Signed-off-by: Steven Chen <chenste@linux.microsoft.com>
Tested-by: Baoquan He <bhe@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
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The amount of memory allocated at kexec load, even with the extra memory
allocated, might not be large enough for the entire measurement list. The
indeterminate interval between kexec 'load' and 'execute' could exacerbate
this problem.
Define two new IMA events, 'kexec_load' and 'kexec_execute', to be
measured as critical data at kexec 'load' and 'execute' respectively.
Report the allocated kexec segment size, IMA binary log size and the
runtime measurements count as part of those events.
These events, and the values reported through them, serve as markers in
the IMA log to verify the IMA events are captured during kexec soft
reboot. The presence of a 'kexec_load' event in between the last two
'boot_aggregate' events in the IMA log implies this is a kexec soft
reboot, and not a cold-boot. And the absence of 'kexec_execute' event
after kexec soft reboot implies missing events in that window which
results in inconsistency with TPM PCR quotes, necessitating a cold boot
for a successful remote attestation.
These critical data events are displayed as hex encoded ascii in the
ascii_runtime_measurement_list. Verifying the critical data hash requires
calculating the hash of the decoded ascii string.
For example, to verify the 'kexec_load' data hash:
sudo cat /sys/kernel/security/integrity/ima/ascii_runtime_measurements
| grep kexec_load | cut -d' ' -f 6 | xxd -r -p | sha256sum
To verify the 'kexec_execute' data hash:
sudo cat /sys/kernel/security/integrity/ima/ascii_runtime_measurements
| grep kexec_execute | cut -d' ' -f 6 | xxd -r -p | sha256sum
Co-developed-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Signed-off-by: Steven Chen <chenste@linux.microsoft.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Tested-by: Stefan Berger <stefanb@linux.ibm.com> # ppc64/kvm
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
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The extra memory allocated for carrying the IMA measurement list across
kexec is hard-coded as half a PAGE. Make it configurable.
Define a Kconfig option, IMA_KEXEC_EXTRA_MEMORY_KB, to configure the
extra memory (in kb) to be allocated for IMA measurements added during
kexec soft reboot. Ensure the default value of the option is set such
that extra half a page of memory for additional measurements is allocated
for the additional measurements.
Update ima_add_kexec_buffer() function to allocate memory based on the
Kconfig option value, rather than the currently hard-coded one.
Suggested-by: Stefan Berger <stefanb@linux.ibm.com>
Co-developed-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Signed-off-by: Steven Chen <chenste@linux.microsoft.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Tested-by: Stefan Berger <stefanb@linux.ibm.com> # ppc64/kvm
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
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kexec 'load' may be called multiple times. Free and realloc the buffer
only if the segment_size is changed from the previous kexec 'load' call.
Signed-off-by: Steven Chen <chenste@linux.microsoft.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Tested-by: Stefan Berger <stefanb@linux.ibm.com> # ppc64/kvm
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
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The IMA log is currently copied to the new kernel during kexec 'load' using
ima_dump_measurement_list(). However, the IMA measurement list copied at
kexec 'load' may result in loss of IMA measurements records that only
occurred after the kexec 'load'. Move the IMA measurement list log copy
from kexec 'load' to 'execute'
Make the kexec_segment_size variable a local static variable within the
file, so it can be accessed during both kexec 'load' and 'execute'.
Define kexec_post_load() as a wrapper for calling ima_kexec_post_load() and
machine_kexec_post_load(). Replace the existing direct call to
machine_kexec_post_load() with kexec_post_load().
When there is insufficient memory to copy all the measurement logs, copy as
much of the measurement list as possible.
Co-developed-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Signed-off-by: Steven Chen <chenste@linux.microsoft.com>
Tested-by: Stefan Berger <stefanb@linux.ibm.com> # ppc64/kvm
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
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The IMA log is currently copied to the new kernel during kexec 'load'
using ima_dump_measurement_list(). However, the log copied at kexec
'load' may result in loss of IMA measurements that only occurred after
kexec "load'. Setup the needed infrastructure to move the IMA log copy
from kexec 'load' to 'execute'.
Define a new IMA hook ima_update_kexec_buffer() as a stub function.
It will be used to call ima_dump_measurement_list() during kexec 'execute'.
Implement ima_kexec_post_load() function to be invoked after the new
Kernel image has been loaded for kexec. ima_kexec_post_load() maps the
IMA buffer to a segment in the newly loaded Kernel. It also registers
the reboot notifier_block to trigger ima_update_kexec_buffer() at
kexec 'execute'.
Set the priority of register_reboot_notifier to INT_MIN to ensure that the
IMA log copy operation will happen at the end of the operation chain, so
that all the IMA measurement records extended into the TPM are copied
Co-developed-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Signed-off-by: Steven Chen <chenste@linux.microsoft.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Tested-by: Stefan Berger <stefanb@linux.ibm.com> # ppc64/kvm
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
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Currently, the function kexec_calculate_store_digests() calculates and
stores the digest of the segment during the kexec_file_load syscall,
where the IMA segment is also allocated.
Later, the IMA segment will be updated with the measurement log at the
kexec execute stage when a kexec reboot is initiated. Therefore, the
digests should be updated for the IMA segment in the normal case. The
problem is that the content of memory segments carried over to the new
kernel during the kexec systemcall can be changed at kexec 'execute'
stage, but the size and the location of the memory segments cannot be
changed at kexec 'execute' stage.
To address this, skip the calculation and storage of the digest for the
IMA segment in kexec_calculate_store_digests() so that it is not added
to the purgatory_sha_regions.
With this change, the IMA segment is not included in the digest
calculation, storage, and verification.
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Co-developed-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Signed-off-by: Steven Chen <chenste@linux.microsoft.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Tested-by: Stefan Berger <stefanb@linux.ibm.com> # ppc64/kvm
[zohar@linux.ibm.com: Fixed Signed-off-by tag to match author's email ]
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
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In the current implementation, the ima_dump_measurement_list() API is
called during the kexec "load" phase, where a buffer is allocated and
the measurement records are copied. Due to this, new events added after
kexec load but before kexec execute are not carried over to the new kernel
during kexec operation
Carrying the IMA measurement list across kexec requires allocating a
buffer and copying the measurement records. Separate allocating the
buffer and copying the measurement records into separate functions in
order to allocate the buffer at kexec 'load' and copy the measurements
at kexec 'execute'.
After moving the vfree() here at this stage in the patch set, the IMA
measurement list fails to verify when doing two consecutive "kexec -s -l"
with/without a "kexec -s -u" in between. Only after "ima: kexec: move
IMA log copy from kexec load to execute" the IMA measurement list verifies
properly with the vfree() here.
Co-developed-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Signed-off-by: Steven Chen <chenste@linux.microsoft.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Tested-by: Stefan Berger <stefanb@linux.ibm.com> # ppc64/kvm
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
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Before making the function local seq_file "file" variable file static
global, rename it to "ima_kexec_file".
Signed-off-by: Steven Chen <chenste@linux.microsoft.com>
Acked-by: Baoquan He <bhe@redhat.com>
Tested-by: Stefan Berger <stefanb@linux.ibm.com> # ppc64/kvm
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
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On IMA policy update, if a measure rule exists in the policy,
IMA_MEASURE is set for ima_policy_flags which makes the violation_check
variable always true. Coupled with a no-action on MAY_READ for a
FILE_CHECK call, we're always taking the inode_lock().
This becomes a performance problem for extremely heavy read-only workloads.
Therefore, prevent this only in the case there's no action to be taken.
Signed-off-by: Frederick Lawler <fred@cloudflare.com>
Acked-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
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Each time a file in policy, that is already opened for read, is opened
for write, a Time-of-Measure-Time-of-Use (ToMToU) integrity violation
audit message is emitted and a violation record is added to the IMA
measurement list. This occurs even if a ToMToU violation has already
been recorded.
Limit the number of ToMToU integrity violations per file open for read.
Note: The IMA_MAY_EMIT_TOMTOU atomic flag must be set from the reader
side based on policy. This may result in a per file open for read
ToMToU violation.
Since IMA_MUST_MEASURE is only used for violations, rename the atomic
IMA_MUST_MEASURE flag to IMA_MAY_EMIT_TOMTOU.
Cc: stable@vger.kernel.org # applies cleanly up to linux-6.6
Tested-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Tested-by: Petr Vorel <pvorel@suse.cz>
Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
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Each time a file in policy, that is already opened for write, is opened
for read, an open-writers integrity violation audit message is emitted
and a violation record is added to the IMA measurement list. This
occurs even if an open-writers violation has already been recorded.
Limit the number of open-writers integrity violations for an existing
file open for write to one. After the existing file open for write
closes (__fput), subsequent open-writers integrity violations may be
emitted.
Cc: stable@vger.kernel.org # applies cleanly up to linux-6.6
Tested-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Tested-by: Petr Vorel <pvorel@suse.cz>
Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
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Commit 0d73a55208e9 ("ima: re-introduce own integrity cache lock")
mistakenly reverted the performance improvement introduced in commit
42a4c603198f0 ("ima: fix ima_inode_post_setattr"). The unused bit mask was
subsequently removed by commit 11c60f23ed13 ("integrity: Remove unused
macro IMA_ACTION_RULE_FLAGS").
Restore the performance improvement by introducing the new mask
IMA_NONACTION_RULE_FLAGS, equal to IMA_NONACTION_FLAGS without
IMA_NEW_FILE, which is not a rule-specific flag.
Finally, reset IMA_NONACTION_RULE_FLAGS instead of IMA_NONACTION_FLAGS in
process_measurement(), if the IMA_CHANGE_ATTR atomic flag is set (after
file metadata modification).
With this patch, new files for which metadata were modified while they are
still open, can be reopened before the last file close (when security.ima
is written), since the IMA_NEW_FILE flag is not cleared anymore. Otherwise,
appraisal fails because security.ima is missing (files with IMA_NEW_FILE
set are an exception).
Cc: stable@vger.kernel.org # v4.16.x
Fixes: 0d73a55208e9 ("ima: re-introduce own integrity cache lock")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
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Fix typos and spelling errors in integrity module comments that were
identified using the codespell tool.
No functional changes - documentation only.
Signed-off-by: Tanya Agarwal <tanyaagarwal25699@gmail.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull AT_EXECVE_CHECK from Kees Cook:
- Implement AT_EXECVE_CHECK flag to execveat(2) (Mickaël Salaün)
- Implement EXEC_RESTRICT_FILE and EXEC_DENY_INTERACTIVE securebits
(Mickaël Salaün)
- Add selftests and samples for AT_EXECVE_CHECK (Mickaël Salaün)
* tag 'AT_EXECVE_CHECK-v6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
ima: instantiate the bprm_creds_for_exec() hook
samples/check-exec: Add an enlighten "inc" interpreter and 28 tests
selftests: ktap_helpers: Fix uninitialized variable
samples/check-exec: Add set-exec
selftests/landlock: Add tests for execveat + AT_EXECVE_CHECK
selftests/exec: Add 32 tests for AT_EXECVE_CHECK and exec securebits
security: Add EXEC_RESTRICT_FILE and EXEC_DENY_INTERACTIVE securebits
exec: Add a new AT_EXECVE_CHECK flag to execveat(2)
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Lines beginning with '#' in the IMA policy are comments and are ignored.
Instead of placing the rule and comment on separate lines, allow the
comment to be suffixed to the IMA policy rule.
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
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With a custom policy similar to the builtin IMA 'tcb' policy [1], arch
specific policy, and a kexec boot command line measurement policy rule,
the kexec boot command line is not measured due to the dont_measure
tmpfs rule.
Limit the builtin 'tcb' dont_measure tmpfs policy rule to just the
"func=FILE_CHECK" hook. Depending on the end users security threat
model, a custom policy might not even include this dont_measure tmpfs
rule.
Note: as a result of this policy rule change, other measurements might
also be included in the IMA-measurement list that previously weren't
included.
[1] https://ima-doc.readthedocs.io/en/latest/ima-policy.html#ima-tcb
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
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The ima_measurements list is append-only and doesn't require
rcu_read_lock() protection. However, lockdep issues a warning when
traversing RCU lists without the read lock:
security/integrity/ima/ima_kexec.c:40 RCU-list traversed in non-reader section!!
Fix this by using the variant of list_for_each_entry_rcu() with the last
argument set to true. This tells the RCU subsystem that traversing this
append-only list without the read lock is intentional and safe.
This change silences the lockdep warning while maintaining the correct
semantics for the append-only list traversal.
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
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Like direct file execution (e.g. ./script.sh), indirect file execution
(e.g. sh script.sh) needs to be measured and appraised. Instantiate
the new security_bprm_creds_for_exec() hook to measure and verify the
indirect file's integrity. Unlike direct file execution, indirect file
execution is optionally enforced by the interpreter.
Differentiate kernel and userspace enforced integrity audit messages.
Co-developed-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Tested-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Mickaël Salaün <mic@digikod.net>
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Link: https://lore.kernel.org/r/20241212174223.389435-9-mic@digikod.net
Signed-off-by: Kees Cook <kees@kernel.org>
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To avoid the following types of error messages due to a failure by the TPM
driver to use the TPM, suspend TPM PCR extensions and the appending of
entries to the IMA log once IMA's reboot notifier has been called. This
avoids trying to use the TPM after the TPM subsystem has been shut down.
[111707.685315][ T1] ima: Error Communicating to TPM chip, result: -19
[111707.685960][ T1] ima: Error Communicating to TPM chip, result: -19
Synchronization with the ima_extend_list_mutex to set
ima_measurements_suspended ensures that the TPM subsystem is not shut down
when IMA holds the mutex while appending to the log and extending the PCR.
The alternative of reading the system_state variable would not provide this
guarantee.
This error could be observed on a ppc64 machine running SuSE Linux where
processes are still accessing files after devices have been shut down.
Suspending the IMA log and PCR extensions shortly before reboot does not
seem to open a significant measurement gap since neither TPM quoting would
work for attestation nor that new log entries could be written to anywhere
after devices have been shut down. However, there's a time window between
the invocation of the reboot notifier and the shutdown of devices. This
includes all subsequently invoked reboot notifiers as well as
kernel_restart_prepare() where __usermodehelper_disable() waits for all
running_helpers to exit. During this time window IMA could now miss log
entries even though attestation would still work. The reboot of the system
shortly after may make this small gap insignificant.
Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm
Pull ima fix from Paul Moore:
"One small patch to fix a function parameter / local variable naming
snafu that went up to you in the current merge window"
* tag 'lsm-pr-20241129' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm:
ima: uncover hidden variable in ima_match_rules()
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The variable name "prop" is inadvertently used twice in
ima_match_rules(), resulting in incorrect use of the local
variable when the function parameter should have been.
Rename the local variable and correct the use of the parameter.
Suggested-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Roberto Sassu <roberto.sassu@huawei.com>
[PM: subj tweak, Roberto's ACK]
Signed-off-by: Paul Moore <paul@paul-moore.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto updates from Herbert Xu:
"API:
- Add sig driver API
- Remove signing/verification from akcipher API
- Move crypto_simd_disabled_for_test to lib/crypto
- Add WARN_ON for return values from driver that indicates memory
corruption
Algorithms:
- Provide crc32-arch and crc32c-arch through Crypto API
- Optimise crc32c code size on x86
- Optimise crct10dif on arm/arm64
- Optimise p10-aes-gcm on powerpc
- Optimise aegis128 on x86
- Output full sample from test interface in jitter RNG
- Retry without padata when it fails in pcrypt
Drivers:
- Add support for Airoha EN7581 TRNG
- Add support for STM32MP25x platforms in stm32
- Enable iproc-r200 RNG driver on BCMBCA
- Add Broadcom BCM74110 RNG driver"
* tag 'v6.13-p1' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (112 commits)
crypto: marvell/cesa - fix uninit value for struct mv_cesa_op_ctx
crypto: cavium - Fix an error handling path in cpt_ucode_load_fw()
crypto: aesni - Move back to module_init
crypto: lib/mpi - Export mpi_set_bit
crypto: aes-gcm-p10 - Use the correct bit to test for P10
hwrng: amd - remove reference to removed PPC_MAPLE config
crypto: arm/crct10dif - Implement plain NEON variant
crypto: arm/crct10dif - Macroify PMULL asm code
crypto: arm/crct10dif - Use existing mov_l macro instead of __adrl
crypto: arm64/crct10dif - Remove remaining 64x64 PMULL fallback code
crypto: arm64/crct10dif - Use faster 16x64 bit polynomial multiply
crypto: arm64/crct10dif - Remove obsolete chunking logic
crypto: bcm - add error check in the ahash_hmac_init function
crypto: caam - add error check to caam_rsa_set_priv_key_form
hwrng: bcm74110 - Add Broadcom BCM74110 RNG driver
dt-bindings: rng: add binding for BCM74110 RNG
padata: Clean up in padata_do_multithreaded()
crypto: inside-secure - Fix the return value of safexcel_xcbcmac_cra_init()
crypto: qat - Fix missing destroy_workqueue in adf_init_aer()
crypto: rsassa-pkcs1 - Reinstate support for legacy protocols
...
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git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm
Pull lsm updates from Paul Moore:
"Thirteen patches, all focused on moving away from the current 'secid'
LSM identifier to a richer 'lsm_prop' structure.
This move will help reduce the translation that is necessary in many
LSMs, offering better performance, and make it easier to support
different LSMs in the future"
* tag 'lsm-pr-20241112' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm:
lsm: remove lsm_prop scaffolding
netlabel,smack: use lsm_prop for audit data
audit: change context data from secid to lsm_prop
lsm: create new security_cred_getlsmprop LSM hook
audit: use an lsm_prop in audit_names
lsm: use lsm_prop in security_inode_getsecid
lsm: use lsm_prop in security_current_getsecid
audit: update shutdown LSM data
lsm: use lsm_prop in security_ipc_getsecid
audit: maintain an lsm_prop in audit_context
lsm: add lsmprop_to_secctx hook
lsm: use lsm_prop in security_audit_rule_match
lsm: add the lsm_prop data structure
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Pull 'struct fd' class updates from Al Viro:
"The bulk of struct fd memory safety stuff
Making sure that struct fd instances are destroyed in the same scope
where they'd been created, getting rid of reassignments and passing
them by reference, converting to CLASS(fd{,_pos,_raw}).
We are getting very close to having the memory safety of that stuff
trivial to verify"
* tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits)
deal with the last remaing boolean uses of fd_file()
css_set_fork(): switch to CLASS(fd_raw, ...)
memcg_write_event_control(): switch to CLASS(fd)
assorted variants of irqfd setup: convert to CLASS(fd)
do_pollfd(): convert to CLASS(fd)
convert do_select()
convert vfs_dedupe_file_range().
convert cifs_ioctl_copychunk()
convert media_request_get_by_fd()
convert spu_run(2)
switch spufs_calls_{get,put}() to CLASS() use
convert cachestat(2)
convert do_preadv()/do_pwritev()
fdget(), more trivial conversions
fdget(), trivial conversions
privcmd_ioeventfd_assign(): don't open-code eventfd_ctx_fdget()
o2hb_region_dev_store(): avoid goto around fdget()/fdput()
introduce "fd_pos" class, convert fdget_pos() users to it.
fdget_raw() users: switch to CLASS(fd_raw)
convert vmsplice() to CLASS(fd)
...
|
|
all failure exits prior to fdget() leave the scope, all matching fdput()
are immediately followed by leaving the scope.
[xfs_ioc_commit_range() chunk moved here as well]
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
Create a new LSM hook security_cred_getlsmprop() which, like
security_cred_getsecid(), fetches LSM specific attributes from the
cred structure. The associated data elements in the audit sub-system
are changed from a secid to a lsm_prop to accommodate multiple possible
LSM audit users.
Cc: linux-integrity@vger.kernel.org
Cc: audit@vger.kernel.org
Cc: selinux@vger.kernel.org
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: subj line tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
Change the security_inode_getsecid() interface to fill in a
lsm_prop structure instead of a u32 secid. This allows for its
callers to gather data from all registered LSMs. Data is provided
for IMA and audit. Change the name to security_inode_getlsmprop().
Cc: linux-integrity@vger.kernel.org
Cc: selinux@vger.kernel.org
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: subj line tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
Change the security_current_getsecid_subj() and
security_task_getsecid_obj() interfaces to fill in a lsm_prop structure
instead of a u32 secid. Audit interfaces will need to collect all
possible security data for possible reporting.
Cc: linux-integrity@vger.kernel.org
Cc: audit@vger.kernel.org
Cc: selinux@vger.kernel.org
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: subject line tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
Change the secid parameter of security_audit_rule_match
to a lsm_prop structure pointer. Pass the entry from the
lsm_prop structure for the approprite slot to the LSM hook.
Change the users of security_audit_rule_match to use the
lsm_prop instead of a u32. The scaffolding function lsmprop_init()
fills the structure with the value of the old secid, ensuring that
it is available to the appropriate module hook. The sources of
the secid, security_task_getsecid() and security_inode_getsecid(),
will be converted to use the lsm_prop structure later in the series.
At that point the use of lsmprop_init() is dropped.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: subject line tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
Function ima_eventdigest_init() calls ima_eventdigest_init_common()
with HASH_ALGO__LAST which is then used to access the array
hash_digest_size[] leading to buffer overrun. Have a conditional
statement to handle this.
Fixes: 9fab303a2cb3 ("ima: fix violation measurement list record")
Signed-off-by: Samasth Norway Ananda <samasth.norway.ananda@oracle.com>
Tested-by: Enrico Bravi (PhD at polito.it) <enrico.bravi@huawei.com>
Cc: stable@vger.kernel.org # 5.19+
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
|
|
A sig_alg backend has just been introduced with the intent of moving all
asymmetric sign/verify algorithms to it one by one.
Migrate the sign/verify operations from rsa-pkcs1pad.c to a separate
rsassa-pkcs1.c which uses the new backend.
Consequently there are now two templates which build on the "rsa"
akcipher_alg:
* The existing "pkcs1pad" template, which is instantiated as an
akcipher_instance and retains the encrypt/decrypt operations of
RSAES-PKCS1-v1_5 (RFC 8017 sec 7.2).
* The new "pkcs1" template, which is instantiated as a sig_instance
and contains the sign/verify operations of RSASSA-PKCS1-v1_5
(RFC 8017 sec 8.2).
In a separate step, rsa-pkcs1pad.c could optionally be renamed to
rsaes-pkcs1.c for clarity. Additional "oaep" and "pss" templates
could be added for RSAES-OAEP and RSASSA-PSS.
Note that it's currently allowed to allocate a "pkcs1pad(rsa)" transform
without specifying a hash algorithm. That makes sense if the transform
is only used for encrypt/decrypt and continues to be supported. But for
sign/verify, such transforms previously did not insert the Full Hash
Prefix into the padding. The resulting message encoding was incompliant
with EMSA-PKCS1-v1_5 (RFC 8017 sec 9.2) and therefore nonsensical.
From here on in, it is no longer allowed to allocate a transform without
specifying a hash algorithm if the transform is used for sign/verify
operations. This simplifies the code because the insertion of the Full
Hash Prefix is no longer optional, so various "if (digest_info)" clauses
can be removed.
There has been a previous attempt to forbid transform allocation without
specifying a hash algorithm, namely by commit c0d20d22e0ad ("crypto:
rsa-pkcs1pad - Require hash to be present"). It had to be rolled back
with commit b3a8c8a5ebb5 ("crypto: rsa-pkcs1pad: Allow hash to be
optional [ver #2]"), presumably because it broke allocation of a
transform which was solely used for encrypt/decrypt, not sign/verify.
Avoid such breakage by allowing transform allocation for encrypt/decrypt
with and without specifying a hash algorithm (and simply ignoring the
hash algorithm in the former case).
So again, specifying a hash algorithm is now mandatory for sign/verify,
but optional and ignored for encrypt/decrypt.
The new sig_alg API uses kernel buffers instead of sglists, which
avoids the overhead of copying signature and digest from sglists back
into kernel buffers. rsassa-pkcs1.c is thus simplified quite a bit.
sig_alg is always synchronous, whereas the underlying "rsa" akcipher_alg
may be asynchronous. So await the result of the akcipher_alg, similar
to crypto_akcipher_sync_{en,de}crypt().
As part of the migration, rename "rsa_digest_info" to "hash_prefix" to
adhere to the spec language in RFC 9580. Otherwise keep the code
unmodified wherever possible to ease reviewing and bisecting. Leave
several simplification and hardening opportunities to separate commits.
rsassa-pkcs1.c uses modern __free() syntax for allocation of buffers
which need to be freed by kfree_sensitive(), hence a DEFINE_FREE()
clause for kfree_sensitive() is introduced herein as a byproduct.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull 'struct fd' updates from Al Viro:
"Just the 'struct fd' layout change, with conversion to accessor
helpers"
* tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
add struct fd constructors, get rid of __to_fd()
struct fd: representation change
introduce fd_file(), convert all accessors to it.
|
|
For any changes of struct fd representation we need to
turn existing accesses to fields into calls of wrappers.
Accesses to struct fd::flags are very few (3 in linux/file.h,
1 in net/socket.c, 3 in fs/overlayfs/file.c and 3 more in
explicit initializers).
Those can be dealt with in the commit converting to
new layout; accesses to struct fd::file are too many for that.
This commit converts (almost) all of f.file to
fd_file(f). It's not entirely mechanical ('file' is used as
a member name more than just in struct fd) and it does not
even attempt to distinguish the uses in pointer context from
those in boolean context; the latter will be eventually turned
into a separate helper (fd_empty()).
NOTE: mass conversion to fd_empty(), tempting as it
might be, is a bad idea; better do that piecewise in commit
that convert from fdget...() to CLASS(...).
[conflicts in fs/fhandle.c, kernel/bpf/syscall.c, mm/memcontrol.c
caught by git; fs/stat.c one got caught by git grep]
[fs/xattr.c conflict]
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
The LSM framework has an existing inode_free_security() hook which
is used by LSMs that manage state associated with an inode, but
due to the use of RCU to protect the inode, special care must be
taken to ensure that the LSMs do not fully release the inode state
until it is safe from a RCU perspective.
This patch implements a new inode_free_security_rcu() implementation
hook which is called when it is safe to free the LSM's internal inode
state. Unfortunately, this new hook does not have access to the inode
itself as it may already be released, so the existing
inode_free_security() hook is retained for those LSMs which require
access to the inode.
Cc: stable@vger.kernel.org
Reported-by: syzbot+5446fbf332b0602ede0b@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/r/00000000000076ba3b0617f65cc8@google.com
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
ssh://ra.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity
Pull integrity fix from Mimi Zohar:
"A single bug fix to properly remove all of the securityfs IMA
measurement lists"
* tag 'integrity-v6.10-fix' of ssh://ra.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
ima: fix wrong zero-assignment during securityfs dentry remove
|
|
A panic happens in ima_match_policy:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
PGD 42f873067 P4D 0
Oops: 0000 [#1] SMP NOPTI
CPU: 5 PID: 1286325 Comm: kubeletmonit.sh
Kdump: loaded Tainted: P
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS 0.0.0 02/06/2015
RIP: 0010:ima_match_policy+0x84/0x450
Code: 49 89 fc 41 89 cf 31 ed 89 44 24 14 eb 1c 44 39
7b 18 74 26 41 83 ff 05 74 20 48 8b 1b 48 3b 1d
f2 b9 f4 00 0f 84 9c 01 00 00 <44> 85 73 10 74 ea
44 8b 6b 14 41 f6 c5 01 75 d4 41 f6 c5 02 74 0f
RSP: 0018:ff71570009e07a80 EFLAGS: 00010207
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000200
RDX: ffffffffad8dc7c0 RSI: 0000000024924925 RDI: ff3e27850dea2000
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffffabfce739
R10: ff3e27810cc42400 R11: 0000000000000000 R12: ff3e2781825ef970
R13: 00000000ff3e2785 R14: 000000000000000c R15: 0000000000000001
FS: 00007f5195b51740(0000)
GS:ff3e278b12d40000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000010 CR3: 0000000626d24002 CR4: 0000000000361ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
ima_get_action+0x22/0x30
process_measurement+0xb0/0x830
? page_add_file_rmap+0x15/0x170
? alloc_set_pte+0x269/0x4c0
? prep_new_page+0x81/0x140
? simple_xattr_get+0x75/0xa0
? selinux_file_open+0x9d/0xf0
ima_file_check+0x64/0x90
path_openat+0x571/0x1720
do_filp_open+0x9b/0x110
? page_counter_try_charge+0x57/0xc0
? files_cgroup_alloc_fd+0x38/0x60
? __alloc_fd+0xd4/0x250
? do_sys_open+0x1bd/0x250
do_sys_open+0x1bd/0x250
do_syscall_64+0x5d/0x1d0
entry_SYSCALL_64_after_hwframe+0x65/0xca
Commit c7423dbdbc9e ("ima: Handle -ESTALE returned by
ima_filter_rule_match()") introduced call to ima_lsm_copy_rule within a
RCU read-side critical section which contains kmalloc with GFP_KERNEL.
This implies a possible sleep and violates limitations of RCU read-side
critical sections on non-PREEMPT systems.
Sleeping within RCU read-side critical section might cause
synchronize_rcu() returning early and break RCU protection, allowing a
UAF to happen.
The root cause of this issue could be described as follows:
| Thread A | Thread B |
| |ima_match_policy |
| | rcu_read_lock |
|ima_lsm_update_rule | |
| synchronize_rcu | |
| | kmalloc(GFP_KERNEL)|
| | sleep |
==> synchronize_rcu returns early
| kfree(entry) | |
| | entry = entry->next|
==> UAF happens and entry now becomes NULL (or could be anything).
| | entry->action |
==> Accessing entry might cause panic.
To fix this issue, we are converting all kmalloc that is called within
RCU read-side critical section to use GFP_ATOMIC.
Fixes: c7423dbdbc9e ("ima: Handle -ESTALE returned by ima_filter_rule_match()")
Cc: stable@vger.kernel.org
Signed-off-by: GUO Zihua <guozihua@huawei.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: fixed missing comment, long lines, !CONFIG_IMA_LSM_RULES case]
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
In case of error during ima_fs_init() all the dentry already created
are removed. {ascii, binary}_securityfs_measurement_lists are freed
calling for each array the remove_securityfs_measurement_lists(). This
function, at the end, assigns to zero the securityfs_measurement_list_count.
This causes during the second call of remove_securityfs_measurement_lists()
to leave the dentry of the array pending, not removing them correctly,
because the securityfs_measurement_list_count is already zero.
Move the securityfs_measurement_list_count = 0 after the two
remove_securityfs_measurement_lists() calls to correctly remove all the
dentry already allocated.
Fixes: 9fa8e7625008 ("ima: add crypto agility support for template-hash algorithm")
Signed-off-by: Enrico Bravi <enrico.bravi@polito.it>
Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
|
|
The template hash showed by the ascii_runtime_measurements and
binary_runtime_measurements is the one calculated using sha1 and there is
no possibility to change this value, despite the fact that the template
hash is calculated using the hash algorithms corresponding to all the PCR
banks configured in the TPM.
Add the support to retrieve the ima log with the template data hash
calculated with a specific hash algorithm.
Add a new file in the securityfs ima directory for each hash algo
configured in a PCR bank of the TPM. Each new file has the name with
the following structure:
{binary, ascii}_runtime_measurements_<hash_algo_name>
Legacy files are kept, to avoid breaking existing applications, but as
symbolic links which point to {binary, ascii}_runtime_measurements_sha1
files. These two files are created even if a TPM chip is not detected or
the sha1 bank is not configured in the TPM.
As example, in the case a TPM chip is present and sha256 is the only
configured PCR bank, the listing of the securityfs ima directory is the
following:
lr--r--r-- [...] ascii_runtime_measurements -> ascii_runtime_measurements_sha1
-r--r----- [...] ascii_runtime_measurements_sha1
-r--r----- [...] ascii_runtime_measurements_sha256
lr--r--r-- [...] binary_runtime_measurements -> binary_runtime_measurements_sha1
-r--r----- [...] binary_runtime_measurements_sha1
-r--r----- [...] binary_runtime_measurements_sha256
--w------- [...] policy
-r--r----- [...] runtime_measurements_count
-r--r----- [...] violations
Signed-off-by: Enrico Bravi <enrico.bravi@polito.it>
Signed-off-by: Silvia Sisinni <silvia.sisinni@polito.it>
Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
|
|
Force a file's integrity to be re-evaluated on file metadata change by
resetting both the IMA and EVM status flags.
Co-developed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
|
|
Move all the variables used for file change detection into a structure
that can be used by IMA and EVM. Implement an inline function for storing
the identification of an inode and one for detecting changes to an inode
based on this new structure.
Co-developed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
|
|
Rename the backing_inode variable to real_inode since it gets its value
from real_inode().
Suggested-by: Amir Goldstein <amir73il@gmail.com>
Co-developed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Acked-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
|
|
-Wflex-array-member-not-at-end is coming in GCC-14, and we are getting
ready to enable it globally.
There is currently an object (`hdr)` in `struct ima_max_digest_data`
that contains a flexible structure (`struct ima_digest_data`):
struct ima_max_digest_data {
struct ima_digest_data hdr;
u8 digest[HASH_MAX_DIGESTSIZE];
} __packed;
So, in order to avoid ending up with a flexible-array member in the
middle of a struct, we use the `__struct_group()` helper to separate
the flexible array from the rest of the members in the flexible
structure:
struct ima_digest_data {
__struct_group(ima_digest_data_hdr, hdr, __packed,
... the rest of the members
);
u8 digest[];
} __packed;
And similarly for `struct evm_ima_xattr_data`.
With the change described above, we can now declare an object of the
type of the tagged `struct ima_digest_data_hdr`, without embedding the
flexible array in the middle of another struct:
struct ima_max_digest_data {
struct ima_digest_data_hdr hdr;
u8 digest[HASH_MAX_DIGESTSIZE];
} __packed;
And similarly for `struct evm_digest` and `struct evm_xattr`.
We also use `container_of()` whenever we need to retrieve a pointer to
the flexible structure.
So, with these changes, fix the following warnings:
security/integrity/evm/evm.h:64:32: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
security/integrity/evm/../integrity.h:40:35: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
security/integrity/evm/../integrity.h:68:32: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
security/integrity/ima/../integrity.h:40:35: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
security/integrity/ima/../integrity.h:68:32: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
security/integrity/integrity.h:40:35: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
security/integrity/integrity.h:68:32: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
security/integrity/platform_certs/../integrity.h:40:35: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
security/integrity/platform_certs/../integrity.h:68:32: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
Link: https://github.com/KSPP/linux/issues/202
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
|
|
The init_module syscall loads an ELF image into kernel space without
measuring the buffer containing the ELF image. To close this kernel
module integrity gap, define a new critical-data record which includes
the hash of the ELF image.
Instead of including the buffer data in the IMA measurement list,
include the hash of the buffer data to avoid large IMA measurement
list records. The buffer data hash would be the same value as the
finit_module syscall file hash.
To enable measuring the init_module buffer and other critical data from
boot, define "ima_policy=critical_data" on the boot command line. Since
builtin policies are not persistent, a custom IMA policy must include
the rule as well: measure func=CRITICAL_DATA label=modules
To verify the template data hash value, first convert the buffer data
hash to binary:
grep "init_module" \
/sys/kernel/security/integrity/ima/ascii_runtime_measurements | \
tail -1 | cut -d' ' -f 6 | xxd -r -p | sha256sum
Reported-by: Ken Goldman <kgold@linux.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
|
|
->d_name.name can change on rename and the earlier value can be freed;
there are conditions sufficient to stabilize it (->d_lock on dentry,
->d_lock on its parent, ->i_rwsem exclusive on the parent's inode,
rename_lock), but none of those are met at any of the sites. Take a stable
snapshot of the name instead.
Link: https://lore.kernel.org/all/20240202182732.GE2087318@ZenIV/
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
|
|
Make the 'ima' LSM independent from the 'integrity' LSM by introducing IMA
own integrity metadata (ima_iint_cache structure, with IMA-specific fields
from the integrity_iint_cache structure), and by managing it directly from
the 'ima' LSM.
Create ima_iint.c and introduce the same integrity metadata management
functions found in iint.c (renamed with ima_). However, instead of putting
metadata in an rbtree, reserve space from IMA in the inode security blob
for a pointer, and introduce the ima_inode_set_iint()/ima_inode_get_iint()
primitives to store/retrieve that pointer. This improves search time from
logarithmic to constant.
Consequently, don't include the inode pointer as field in the
ima_iint_cache structure, since the association with the inode is clear.
Since the inode field is missing in ima_iint_cache, pass the extra inode
parameter to ima_get_verity_digest().
Prefer storing the pointer instead of the entire ima_iint_cache structure,
to avoid too much memory pressure. Use the same mechanism as before, a
cache named ima_iint_cache (renamed from iint_cache), to quickly allocate
a new ima_iint_cache structure when requested by the IMA policy.
Create the new ima_iint_cache in ima_iintcache_init(),
called by init_ima_lsm(), during the initialization of the 'ima' LSM. And,
register ima_inode_free_security() to free the ima_iint_cache structure, if
exists.
Replace integrity_iint_cache with ima_iint_cache in various places of the
IMA code. Also, replace integrity_inode_get() and integrity_iint_find(),
respectively with ima_inode_get() and ima_iint_find().
Finally, move the remaining IMA-specific flags
to security/integrity/ima/ima.h, since they are now unnecessary in the
common integrity layer.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
Define a new structure for EVM-specific metadata, called evm_iint_cache,
and embed it in the inode security blob. Introduce evm_iint_inode() to
retrieve metadata, and register evm_inode_alloc_security() for the
inode_alloc_security LSM hook, to initialize the structure (before
splitting metadata, this task was done by iint_init_always()).
Keep the non-NULL checks after calling evm_iint_inode() except in
evm_inode_alloc_security(), to take into account inodes for which
security_inode_alloc() was not called. When using shared metadata,
obtaining a NULL pointer from integrity_iint_find() meant that the file
wasn't in the IMA policy. Now, because IMA and EVM use disjoint metadata,
the EVM status has to be stored for every inode regardless of the IMA
policy.
Given that from now on EVM relies on its own metadata, remove the iint
parameter from evm_verifyxattr(). Also, directly retrieve the iint in
evm_verify_hmac(), called by both evm_verifyxattr() and
evm_verify_current_integrity(), since now there is no performance penalty
in retrieving EVM metadata (constant time).
Replicate the management of the IMA_NEW_FILE flag, by introducing
evm_post_path_mknod() and evm_file_release() to respectively set and clear
the newly introduced flag EVM_NEW_FILE, at the same time IMA does. Like for
IMA, select CONFIG_SECURITY_PATH when EVM is enabled, to ensure that files
are marked as new.
Unlike ima_post_path_mknod(), evm_post_path_mknod() cannot check if a file
must be appraised. Thus, it marks all affected files. Also, it does not
clear EVM_NEW_FILE depending on i_version, but that is not a problem
because IMA_NEW_FILE is always cleared when set in ima_check_last_writer().
Move the EVM-specific flag EVM_IMMUTABLE_DIGSIG to
security/integrity/evm/evm.h, since that definition is now unnecessary in
the common integrity layer.
Finally, switch to the LSM reservation mechanism for the EVM xattr, and
consequently decrement by one the number of xattrs to allocate in
security_inode_init_security().
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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A few additional IMA hooks are needed to reset the cached appraisal
status, causing the file's integrity to be re-evaluated on next access.
Register these IMA-appraisal only functions separately from the rest of IMA
functions, as appraisal is a separate feature not necessarily enabled in
the kernel configuration.
Reuse the same approach as for other IMA functions, move hardcoded calls
from various places in the kernel to the LSM infrastructure. Declare the
functions as static and register them as hook implementations in
init_ima_appraise_lsm(), called by init_ima_lsm().
Also move the inline function ima_inode_remove_acl() from the public ima.h
header to ima_appraise.c.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Move hardcoded IMA function calls (not appraisal-specific functions) from
various places in the kernel to the LSM infrastructure, by introducing a
new LSM named 'ima' (at the end of the LSM list and always enabled like
'integrity').
Having IMA before EVM in the Makefile is sufficient to preserve the
relative order of the new 'ima' LSM in respect to the upcoming 'evm' LSM,
and thus the order of IMA and EVM function calls as when they were
hardcoded.
Make moved functions as static (except ima_post_key_create_or_update(),
which is not in ima_main.c), and register them as implementation of the
respective hooks in the new function init_ima_lsm().
Select CONFIG_SECURITY_PATH, to ensure that the path-based LSM hook
path_post_mknod is always available and ima_post_path_mknod() is always
executed to mark files as new, as before the move.
A slight difference is that IMA and EVM functions registered for the
inode_post_setattr, inode_post_removexattr, path_post_mknod,
inode_post_create_tmpfile, inode_post_set_acl and inode_post_remove_acl
won't be executed for private inodes. Since those inodes are supposed to be
fs-internal, they should not be of interest to IMA or EVM. The S_PRIVATE
flag is used for anonymous inodes, hugetlbfs, reiserfs xattrs, XFS scrub
and kernel-internal tmpfs files.
Conditionally register ima_post_key_create_or_update() if
CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS is enabled. Also, conditionally register
ima_kernel_module_request() if CONFIG_INTEGRITY_ASYMMETRIC_KEYS is enabled.
Finally, add the LSM_ID_IMA case in lsm_list_modules_test.c.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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In preparation for removing the 'integrity' LSM, move
integrity_kernel_module_request() to IMA, and rename it to
ima_kernel_module_request(). Rewrite the function documentation, to explain
better what the problem is.
Compile it conditionally if CONFIG_INTEGRITY_ASYMMETRIC_KEYS is enabled,
and call it from security.c (removed afterwards with the move of IMA to the
LSM infrastructure).
Adding this hook cannot be avoided, since IMA has no control on the flags
passed to crypto_alloc_sig() in public_key_verify_signature(), and thus
cannot pass CRYPTO_NOLOAD, which solved the problem for EVM hashing with
commit e2861fa71641 ("evm: Don't deadlock if a crypto algorithm is
unavailable").
EVM alone does not need to implement this hook, first because there is no
mutex to deadlock, and second because even if it had it, there should be a
recursive call. However, since verification from EVM can be initiated only
by setting inode metadata, deadlock would occur if modprobe would do the
same while loading a kernel module (which is unlikely).
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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