user/sven/linux.git/include/linux/ima.h, branch v5.8.8

ima: verify mprotect change is consistent with mmap policy

2020-05-22T18:41:04Z

Files can be mmap'ed read/write and later changed to execute to circumvent IMA's mmap appraise policy rules. Due to locking issues (mmap semaphore would be taken prior to i_mutex), files can not be measured or appraised at this point. Eliminate this integrity gap, by denying the mprotect PROT_EXECUTE change, if an mmap appraise policy rule exists. On mprotect change success, return 0. On failure, return -EACESS. Reviewed-by: Lakshmi Ramasubramanian Signed-off-by: Mimi Zohar

ima: add a new CONFIG for loading arch-specific policies

2020-03-12T11:43:57Z

Every time a new architecture defines the IMA architecture specific functions - arch_ima_get_secureboot() and arch_ima_get_policy(), the IMA include file needs to be updated. To avoid this "noise", this patch defines a new IMA Kconfig IMA_SECURE_AND_OR_TRUSTED_BOOT option, allowing the different architectures to select it. Suggested-by: Linus Torvalds Signed-off-by: Nayna Jain Acked-by: Ard Biesheuvel Acked-by: Philipp Rudo (s390) Acked-by: Michael Ellerman (powerpc) Signed-off-by: Mimi Zohar

ima: add the ability to query the cached hash of a given file

2020-01-22T20:22:51Z

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 Reviewed-by: KP Singh Signed-off-by: Mimi Zohar

IMA: fix measuring asymmetric keys Kconfig

2020-01-09T19:06:06Z

As a result of the asymmetric public keys subtype Kconfig option being defined as tristate, with the existing IMA Makefile, ima_asymmetric_keys.c could be built as a kernel module. To prevent this from happening, this patch defines and uses an intermediate Kconfig boolean option named IMA_MEASURE_ASYMMETRIC_KEYS. Signed-off-by: Lakshmi Ramasubramanian Suggested-by: James.Bottomley Cc: David Howells Cc: Jarkko Sakkinen Reported-by: kbuild test robot # ima_asymmetric_keys.c is built as a kernel module. Fixes: 88e70da170e8 ("IMA: Define an IMA hook to measure keys") Fixes: cb1aa3823c92 ("KEYS: Call the IMA hook to measure keys") [zohar@linux.ibm.com: updated patch description] Signed-off-by: Mimi Zohar

KEYS: Call the IMA hook to measure keys

2019-12-12T13:53:50Z

Call the IMA hook from key_create_or_update() function to measure the payload when a new key is created or an existing key is updated. This patch adds the call to the IMA hook from key_create_or_update() function to measure the key on key create or update. Signed-off-by: Lakshmi Ramasubramanian Cc: David Howells Cc: Jarkko Sakkinen Signed-off-by: Mimi Zohar

powerpc/ima: Add support to initialize ima policy rules

2019-11-12T01:25:49Z

PowerNV systems use a Linux-based bootloader, which rely on the IMA subsystem to enforce different secure boot modes. Since the verification policy may differ based on the secure boot mode of the system, the policies must be defined at runtime. This patch implements arch-specific support to define IMA policy rules based on the runtime secure boot mode of the system. This patch provides arch-specific IMA policies if PPC_SECURE_BOOT config is enabled. Signed-off-by: Nayna Jain Signed-off-by: Mimi Zohar Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/1572492694-6520-3-git-send-email-zohar@linux.ibm.com

Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

2019-09-28T15:14:15Z

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 ...

kexec: Allow kexec_file() with appropriate IMA policy when locked down

2019-08-20T04:54:16Z

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 Acked-by: Mimi Zohar Cc: Dmitry Kasatkin Cc: linux-integrity@vger.kernel.org Signed-off-by: James Morris

Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity

2019-07-09T03:28:59Z

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

IMA: Define a new hook to measure the kexec boot command line arguments

2019-06-24T12:29:57Z

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 Signed-off-by: Mimi Zohar