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2020-02-28integrity: Remove duplicate pr_fmt definitionsTushar Sugandhi1-2/+0
The #define for formatting log messages, pr_fmt, is duplicated in the files under security/integrity. This change moves the definition to security/integrity/integrity.h and removes the duplicate definitions in the other files under security/integrity. With this change, the messages in the following files will be prefixed with 'integrity'. security/integrity/platform_certs/platform_keyring.c security/integrity/platform_certs/load_powerpc.c security/integrity/platform_certs/load_uefi.c security/integrity/iint.c e.g. "integrity: Error adding keys to platform keyring %s\n" And the messages in the following file will be prefixed with 'ima'. security/integrity/ima/ima_mok.c e.g. "ima: Allocating IMA blacklist keyring.\n" For the rest of the files under security/integrity, there will be no change in the message format. Suggested-by: Shuah Khan <skhan@linuxfoundation.org> Suggested-by: Joe Perches <joe@perches.com> Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-02-28IMA: Add log statements for failure conditionsTushar Sugandhi1-0/+3
process_buffer_measurement() does not have log messages for failure conditions. This change adds a log statement in the above function. Suggested-by: Joe Perches <joe@perches.com> Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-01-22ima: add the ability to query the cached hash of a given fileFlorent Revest1-0/+49
This allows other parts of the kernel (perhaps a stacked LSM allowing system monitoring, eg. the proposed KRSI LSM [1]) to retrieve the hash of a given file from IMA if it's present in the iint cache. It's true that the existence of the hash means that it's also in the audit logs or in /sys/kernel/security/ima/ascii_runtime_measurements, but it can be difficult to pull that information out for every subsequent exec. This is especially true if a given host has been up for a long time and the file was first measured a long time ago. It should be kept in mind that this function gives access to cached entries which can be removed, for instance on security_inode_free(). This is based on Peter Moody's patch: https://sourceforge.net/p/linux-ima/mailman/message/33036180/ [1] https://lkml.org/lkml/2019/9/10/393 Signed-off-by: Florent Revest <revest@google.com> Reviewed-by: KP Singh <kpsingh@chromium.org> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-12-12IMA: Add support to limit measuring keysLakshmi Ramasubramanian1-4/+5
Limit measuring keys to those keys being loaded onto a given set of keyrings only and when the user id (uid) matches if uid is specified in the policy. This patch defines a new IMA policy option namely "keyrings=" that can be used to specify a set of keyrings. If this option is specified in the policy for "measure func=KEY_CHECK" then only the keys loaded onto a keyring given in the "keyrings=" option are measured. If uid is specified in the policy then the key is measured only if the current user id matches the one specified in the policy. Added a new parameter namely "keyring" (name of the keyring) to process_buffer_measurement(). The keyring name is passed to ima_get_action() to determine the required action. ima_match_rules() is updated to check keyring in the policy, if specified, for KEY_CHECK function. Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-12-12IMA: Check IMA policy flagLakshmi Ramasubramanian1-0/+3
process_buffer_measurement() may be called prior to IMA being initialized (for instance, when the IMA hook is called when a key is added to the .builtin_trusted_keys keyring), which would result in a kernel panic. This patch adds the check in process_buffer_measurement() to return immediately if IMA is not initialized yet. Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-11-12ima: Check against blacklisted hashes for files with modsigNayna Jain1-4/+8
Asymmetric private keys are used to sign multiple files. The kernel currently supports checking against blacklisted keys. However, if the public key is blacklisted, any file signed by the blacklisted key will automatically fail signature verification. Blacklisting the public key is not fine enough granularity, as we might want to only blacklist a particular file. This patch adds support for checking against the blacklisted hash of the file, without the appended signature, based on the IMA policy. It defines a new policy option "appraise_flag=check_blacklist". In addition to the blacklisted binary hashes stored in the firmware "dbx" variable, the Linux kernel may be configured to load blacklisted binary hashes onto the .blacklist keyring as well. The following example shows how to blacklist a specific kernel module hash. $ sha256sum kernel/kheaders.ko 77fa889b35a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3 kernel/kheaders.ko $ grep BLACKLIST .config CONFIG_SYSTEM_BLACKLIST_KEYRING=y CONFIG_SYSTEM_BLACKLIST_HASH_LIST="blacklist-hash-list" $ cat certs/blacklist-hash-list "bin:77fa889b35a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3" Update the IMA custom measurement and appraisal policy rules (/etc/ima-policy): measure func=MODULE_CHECK template=ima-modsig appraise func=MODULE_CHECK appraise_flag=check_blacklist appraise_type=imasig|modsig After building, installing, and rebooting the kernel: 545660333 ---lswrv 0 0 \_ blacklist: bin:77fa889b35a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3 measure func=MODULE_CHECK template=ima-modsig appraise func=MODULE_CHECK appraise_flag=check_blacklist appraise_type=imasig|modsig modprobe: ERROR: could not insert 'kheaders': Permission denied 10 0c9834db5a0182c1fb0cdc5d3adcf11a11fd83dd ima-sig sha256:3bc6ed4f0b4d6e31bc1dbc9ef844605abc7afdc6d81a57d77a1ec9407997c40 2 /usr/lib/modules/5.4.0-rc3+/kernel/kernel/kheaders.ko 10 82aad2bcc3fa8ed94762356b5c14838f3bcfa6a0 ima-modsig sha256:3bc6ed4f0b4d6e31bc1dbc9ef844605abc7afdc6d81a57d77a1ec9407997c40 2 /usr/lib/modules/5.4.0rc3+/kernel/kernel/kheaders.ko sha256:77fa889b3 5a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3 3082029a06092a864886f70d010702a082028b30820287020101310d300b0609608648 016503040201300b06092a864886f70d01070131820264.... 10 25b72217cc1152b44b134ce2cd68f12dfb71acb3 ima-buf sha256:8b58427fedcf8f4b20bc8dc007f2e232bf7285d7b93a66476321f9c2a3aa132 b blacklisted-hash 77fa889b35a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3 Signed-off-by: Nayna Jain <nayna@linux.ibm.com> [zohar@linux.ibm.com: updated patch description] Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1572492694-6520-8-git-send-email-zohar@linux.ibm.com
2019-11-12ima: Make process_buffer_measurement() genericNayna Jain1-18/+40
process_buffer_measurement() is limited to measuring the kexec boot command line. This patch makes process_buffer_measurement() more generic, allowing it to measure other types of buffer data (e.g. blacklisted binary hashes or key hashes). process_buffer_measurement() may be called directly from an IMA hook or as an auxiliary measurement record. In both cases the buffer measurement is based on policy. This patch modifies the function to conditionally retrieve the policy defined PCR and template for the IMA hook case. Signed-off-by: Nayna Jain <nayna@linux.ibm.com> [zohar@linux.ibm.com: added comment in process_buffer_measurement()] Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1572492694-6520-6-git-send-email-zohar@linux.ibm.com
2019-09-28Merge branch 'next-lockdown' of ↵Linus Torvalds1-2/+2
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 9d1f8be5cf42 ("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 ...
2019-08-19kexec: Allow kexec_file() with appropriate IMA policy when locked downMatthew Garrett1-1/+1
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>
2019-08-19kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCEJiri Bohac1-1/+1
This is a preparatory patch for kexec_file_load() lockdown. A locked down kernel needs to prevent unsigned kernel images from being loaded with kexec_file_load(). Currently, the only way to force the signature verification is compiling with KEXEC_VERIFY_SIG. This prevents loading usigned images even when the kernel is not locked down at runtime. This patch splits KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE. Analogous to the MODULE_SIG and MODULE_SIG_FORCE for modules, KEXEC_SIG turns on the signature verification but allows unsigned images to be loaded. KEXEC_SIG_FORCE disallows images without a valid signature. Signed-off-by: Jiri Bohac <jbohac@suse.cz> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Matthew Garrett <mjg59@google.com> cc: kexec@lists.infradead.org Signed-off-by: James Morris <jmorris@namei.org>
2019-08-05ima: Store the measurement again when appraising a modsigThiago Jung Bauermann1-3/+12
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>
2019-08-05ima: Define ima-modsig templateThiago Jung Bauermann1-1/+1
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>
2019-08-05ima: Collect modsigThiago Jung Bauermann1-1/+1
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>
2019-08-05ima: Implement support for module-style appended signaturesThiago Jung Bauermann1-2/+9
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>
2019-07-08Merge branch 'next-integrity' of ↵Linus Torvalds1-6/+117
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
2019-06-30IMA: Define a new template field bufPrakhar Srivastava1-1/+3
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>
2019-06-24IMA: Define a new hook to measure the kexec boot command line argumentsPrakhar Srivastava1-0/+72
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>
2019-06-19IMA: support for per policy rule template formatsMatthew Garrett1-4/+5
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>
2019-06-14ima: use the lsm policy update notifierJanne Karhunen1-0/+8
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>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441Thomas Gleixner1-5/+1
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>
2019-06-04ima: prevent a file already mmap'ed write to be mmap'ed executeMimi Zohar1-2/+30
The kernel calls deny_write_access() to prevent a file already opened for write from being executed and also prevents files being executed from being opened for write. For some reason this does not extend to files being mmap'ed execute. From an IMA perspective, measuring/appraising the integrity of a file being mmap'ed shared execute, without first making sure the file cannot be modified, makes no sense. This patch prevents files, in policy, already mmap'ed shared write, from being mmap'ed execute. Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-02-04ima: define ima_post_create_tmpfile() hook and add missing callMimi Zohar1-2/+33
If tmpfiles can be made persistent, then newly created tmpfiles need to be treated like any other new files in policy. This patch indicates which newly created tmpfiles are in policy, causing the file hash to be calculated on __fput(). Reported-by: Ignaz Forster <ignaz.forster@gmx.de> [rgoldwyn@suse.com: Call ima_post_create_tmpfile() in vfs_tmpfile() as opposed to do_tmpfile(). This will help the case for overlayfs where copy_up is denied while overwriting a file.] Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-01-02Merge branch 'next-integrity' of ↵Linus Torvalds1-7/+14
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull integrity updates from James Morris: "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 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)" * 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: integrity: Remove references to module keyring ima: Use inode_is_open_for_write ima: Support platform keyring for kernel appraisal efi: Allow the "db" UEFI variable to be suppressed efi: Import certificates from UEFI Secure Boot efi: Add an EFI signature blob parser efi: Add EFI signature data types integrity: Load certs to the platform keyring integrity: Define a trusted platform keyring selftests/ima: kexec_load syscall test ima: don't measure/appraise files on efivarfs x86/ima: retry detecting secure boot mode docs: Extend trusted keys documentation for TPM 2.0 x86/ima: define arch_get_ima_policy() for x86 ima: add support for arch specific policies ima: refactor ima_init_policy() ima: prevent kexec_load syscall based on runtime secureboot flag x86/ima: define arch_ima_get_secureboot integrity: support new struct public_key_signature encoding field
2018-12-20security: integrity: partial revert of make ima_main explicitly non-modularPaul Gortmaker1-1/+1
In commit 4f83d5ea643a ("security: integrity: make ima_main explicitly non-modular") I'd removed <linux/module.h> after assuming that the function is_module_sig_enforced() was an LSM function and not a core kernel module function. Unfortunately the typical .config selections used in build testing provide an implicit <linux/module.h> presence, and so normal/typical build testing did not immediately reveal my incorrect assumption. Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com> Cc: James Morris <james.l.morris@oracle.com> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: linux-ima-devel@lists.sourceforge.net Cc: linux-security-module@vger.kernel.org Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: James Morris <james.morris@microsoft.com>
2018-12-17Merge branch 'next-integrity' of ↵James Morris1-7/+14
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.)
2018-12-12ima: Use inode_is_open_for_writeNikolay Borisov1-1/+1
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>
2018-12-12security: integrity: make ima_main explicitly non-modularPaul Gortmaker1-4/+3
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>
2018-12-11ima: prevent kexec_load syscall based on runtime secureboot flagNayna Jain1-6/+13
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>
2018-10-10security/integrity: constify some read-only dataEric Biggers1-1/+1
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>
2018-08-15Merge branch 'next-general' of ↵Linus Torvalds1-14/+54
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
2018-07-16ima: based on policy warn about loading firmware (pre-allocated buffer)Mimi Zohar1-0/+8
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 a098ecd2fa7d ("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>
2018-07-16module: replace the existing LSM hook in init_moduleMimi Zohar1-13/+10
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>
2018-07-16ima: based on policy require signed firmware (sysfs fallback)Mimi Zohar1-1/+9
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>
2018-07-16ima: based on policy require signed kexec kernel imagesMimi Zohar1-0/+27
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>
2018-07-12IMA: don't propagate opened through the entire thingAl Viro1-8/+8
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>
2018-05-31ima: use match_string() helperYisheng Xie1-7/+4
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>
2018-05-22ima: based on policy verify firmware signatures (pre-allocated buffer)Mimi Zohar1-0/+1
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>
2018-05-17ima: Remove unused variable ima_initializedPetr Vorel1-5/+2
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>
2018-03-25ima: Fallback to the builtin hash algorithmPetr Vorel1-0/+13
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>
2018-03-23ima: fail signature verification based on policyMimi Zohar1-1/+2
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>
2018-03-23ima: re-evaluate files on privileged mounted filesystemsMimi Zohar1-2/+11
This patch addresses the fuse privileged mounted filesystems in a "secure" environment, with a correctly enforced security policy, which is willing to assume the inherent risk of specific fuse filesystems that are well defined and properly implemented. As there is no way for the kernel to detect file changes, the kernel ignores the cached file integrity results and re-measures, re-appraises, and re-audits the file. Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Seth Forshee <seth.forshee@canonical.com> Cc: Dongsu Park <dongsu@kinvolk.io> Cc: Alban Crequy <alban@kinvolk.io> Acked-by: Serge Hallyn <serge@hallyn.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-03-23IMA: Support using new creds in appraisal policyMatthew Garrett1-10/+32
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
2018-02-01iversion: Rename make inode_cmp_iversion{+raw} to inode_eq_iversion{+raw}Goffredo Baroncelli1-1/+1
The function inode_cmp_iversion{+raw} is counter-intuitive, because it returns true when the counters are different and false when these are equal. Rename it to inode_eq_iversion{+raw}, which will returns true when the counters are equal and false otherwise. Signed-off-by: Goffredo Baroncelli <kreijack@inwind.it> Signed-off-by: Jeff Layton <jlayton@redhat.com>
2018-01-31Merge branch 'next-integrity' of ↵Linus Torvalds1-26/+66
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull integrity updates from James Morris: "This contains a mixture of bug fixes, code cleanup, and new functionality. Of note is the integrity cache locking fix, file change detection, and support for a new EVM portable and immutable signature type. The re-introduction of the integrity cache lock (iint) fixes the problem of attempting to take the i_rwsem shared a second time, when it was previously taken exclusively. Defining atomic flags resolves the original iint/i_rwsem circular locking - accessing the file data vs. modifying the file metadata. Although it fixes the O_DIRECT problem as well, a subsequent patch is needed to remove the explicit O_DIRECT prevention. For performance reasons, detecting when a file has changed and needs to be re-measured, re-appraised, and/or re-audited, was limited to after the last writer has closed, and only if the file data has changed. Detecting file change is based on i_version. For filesystems that do not support i_version, remote filesystems, or userspace filesystems, the file was measured, appraised and/or audited once and never re-evaluated. Now local filesystems, which do not support i_version or are not mounted with the i_version option, assume the file has changed and are required to re-evaluate the file. This change does not address detecting file change on remote or userspace filesystems. Unlike file data signatures, which can be included and distributed in software packages (eg. rpm, deb), the existing EVM signature, which protects the file metadata, could not be included in software packages, as it includes file system specific information (eg. i_ino, possibly the UUID). This pull request defines a new EVM portable and immutable file metadata signature format, which can be included in software packages" * 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: ima/policy: fix parsing of fsuuid ima: Use i_version only when filesystem supports it integrity: remove unneeded initializations in integrity_iint_cache entries ima: log message to module appraisal error ima: pass filename to ima_rdwr_violation_check() ima: Fix line continuation format ima: support new "hash" and "dont_hash" policy actions ima: re-introduce own integrity cache lock EVM: Add support for portable signature format EVM: Allow userland to permit modification of EVM-protected metadata ima: relax requiring a file signature for new files with zero length
2018-01-29IMA: switch IMA over to new i_version APIJeff Layton1-1/+2
Signed-off-by: Jeff Layton <jlayton@redhat.com>
2017-12-18ima: Use i_version only when filesystem supports itSascha Hauer1-1/+2
i_version is only supported by a filesystem when the SB_I_VERSION flag is set. This patch tests for the SB_I_VERSION flag before using i_version. If we can't use i_version to detect a file change then we must assume the file has changed in the last_writer path and remeasure it. On filesystems without i_version support IMA used to measure a file only once and didn't detect any changes to a file. With this patch IMA now works properly on these filesystems. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-18ima: log message to module appraisal errorBruno E. O. Meneguele1-1/+3
Simple but useful message log to the user in case of module appraise is forced and fails due to the lack of file descriptor, that might be caused by kmod calls to compressed modules. Signed-off-by: Bruno E. O. Meneguele <brdeoliv@redhat.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-18ima: pass filename to ima_rdwr_violation_check()Roberto Sassu1-3/+3
ima_rdwr_violation_check() retrieves the full path of a measured file by calling ima_d_path(). If process_measurement() calls this function, it reuses the pointer and passes it to the functions to measure/appraise/audit an accessed file. After commit bc15ed663e7e ("ima: fix ima_d_path() possible race with rename"), ima_d_path() first tries to retrieve the full path by calling d_absolute_path() and, if there is an error, copies the dentry name to the buffer passed as argument. However, ima_rdwr_violation_check() passes to ima_d_path() the pointer of a local variable. process_measurement() might be reusing the pointer to an area in the stack which may have been already overwritten after ima_rdwr_violation_check() returned. Correct this issue by passing to ima_rdwr_violation_check() the pointer of a buffer declared in process_measurement(). Fixes: bc15ed663e7e ("ima: fix ima_d_path() possible race with rename") Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-18ima: support new "hash" and "dont_hash" policy actionsMimi Zohar1-0/+12
The builtin ima_appraise_tcb policy, which is specified on the boot command line, can be replaced with a custom policy, normally early in the boot process. Custom policies can be more restrictive in some ways, like requiring file signatures, but can be less restrictive in other ways, like not appraising mutable files. With a less restrictive policy in place, files in the builtin policy might not be hashed and labeled with a security.ima hash. On reboot, files which should be labeled in the ima_appraise_tcb are not labeled, possibly preventing the system from booting properly. To resolve this problem, this patch extends the existing IMA policy actions "measure", "dont_measure", "appraise", "dont_appraise", and "audit" with "hash" and "dont_hash". The new "hash" action will write the file hash as security.ima, but without requiring the file to be appraised as well. For example, the builtin ima_appraise_tcb policy includes the rule, "appraise fowner=0". Adding the "hash fowner=0" rule to a custom policy, will cause the needed file hashes to be calculated and written as security.ima xattrs. Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
2017-12-13ima: Use i_version only when filesystem supports itSascha Hauer1-1/+2
i_version is only supported by a filesystem when the SB_I_VERSION flag is set. This patch tests for the SB_I_VERSION flag before using i_version. If we can't use i_version to detect a file change then we must assume the file has changed in the last_writer path and remeasure it. On filesystems without i_version support IMA used to measure a file only once and didn't detect any changes to a file. With this patch IMA now works properly on these filesystems. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Jeff Layton <jlayton@redhat.com>
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