forked from luck/tmp_suning_uos_patched
aefcf2f4b5
Pull kernel lockdown mode from James Morris:
"This is the latest iteration of the kernel lockdown patchset, from
Matthew Garrett, David Howells and others.
From the original description:
This patchset introduces an optional kernel lockdown feature,
intended to strengthen the boundary between UID 0 and the kernel.
When enabled, various pieces of kernel functionality are restricted.
Applications that rely on low-level access to either hardware or the
kernel may cease working as a result - therefore this should not be
enabled without appropriate evaluation beforehand.
The majority of mainstream distributions have been carrying variants
of this patchset for many years now, so there's value in providing a
doesn't meet every distribution requirement, but gets us much closer
to not requiring external patches.
There are two major changes since this was last proposed for mainline:
- Separating lockdown from EFI secure boot. Background discussion is
covered here: https://lwn.net/Articles/751061/
- Implementation as an LSM, with a default stackable lockdown LSM
module. This allows the lockdown feature to be policy-driven,
rather than encoding an implicit policy within the mechanism.
The new locked_down LSM hook is provided to allow LSMs to make a
policy decision around whether kernel functionality that would allow
tampering with or examining the runtime state of the kernel should be
permitted.
The included lockdown LSM provides an implementation with a simple
policy intended for general purpose use. This policy provides a coarse
level of granularity, controllable via the kernel command line:
lockdown={integrity|confidentiality}
Enable the kernel lockdown feature. If set to integrity, kernel features
that allow userland to modify the running kernel are disabled. If set to
confidentiality, kernel features that allow userland to extract
confidential information from the kernel are also disabled.
This may also be controlled via /sys/kernel/security/lockdown and
overriden by kernel configuration.
New or existing LSMs may implement finer-grained controls of the
lockdown features. Refer to the lockdown_reason documentation in
include/linux/security.h for details.
The lockdown feature has had signficant design feedback and review
across many subsystems. This code has been in linux-next for some
weeks, with a few fixes applied along the way.
Stephen Rothwell noted that commit 9d1f8be5cf
("bpf: Restrict bpf
when kernel lockdown is in confidentiality mode") is missing a
Signed-off-by from its author. Matthew responded that he is providing
this under category (c) of the DCO"
* 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (31 commits)
kexec: Fix file verification on S390
security: constify some arrays in lockdown LSM
lockdown: Print current->comm in restriction messages
efi: Restrict efivar_ssdt_load when the kernel is locked down
tracefs: Restrict tracefs when the kernel is locked down
debugfs: Restrict debugfs when the kernel is locked down
kexec: Allow kexec_file() with appropriate IMA policy when locked down
lockdown: Lock down perf when in confidentiality mode
bpf: Restrict bpf when kernel lockdown is in confidentiality mode
lockdown: Lock down tracing and perf kprobes when in confidentiality mode
lockdown: Lock down /proc/kcore
x86/mmiotrace: Lock down the testmmiotrace module
lockdown: Lock down module params that specify hardware parameters (eg. ioport)
lockdown: Lock down TIOCSSERIAL
lockdown: Prohibit PCMCIA CIS storage when the kernel is locked down
acpi: Disable ACPI table override if the kernel is locked down
acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down
ACPI: Limit access to custom_method when the kernel is locked down
x86/msr: Restrict MSR access when the kernel is locked down
x86: Lock down IO port access when the kernel is locked down
...
313 lines
10 KiB
Plaintext
313 lines
10 KiB
Plaintext
# SPDX-License-Identifier: GPL-2.0-only
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# IBM Integrity Measurement Architecture
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#
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config IMA
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bool "Integrity Measurement Architecture(IMA)"
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select SECURITYFS
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select CRYPTO
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select CRYPTO_HMAC
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select CRYPTO_MD5
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select CRYPTO_SHA1
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select CRYPTO_HASH_INFO
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select TCG_TPM if HAS_IOMEM && !UML
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select TCG_TIS if TCG_TPM && X86
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select TCG_CRB if TCG_TPM && ACPI
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select TCG_IBMVTPM if TCG_TPM && PPC_PSERIES
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select INTEGRITY_AUDIT if AUDIT
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help
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The Trusted Computing Group(TCG) runtime Integrity
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Measurement Architecture(IMA) maintains a list of hash
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values of executables and other sensitive system files,
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as they are read or executed. If an attacker manages
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to change the contents of an important system file
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being measured, we can tell.
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If your system has a TPM chip, then IMA also maintains
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an aggregate integrity value over this list inside the
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TPM hardware, so that the TPM can prove to a third party
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whether or not critical system files have been modified.
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Read <http://www.usenix.org/events/sec04/tech/sailer.html>
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to learn more about IMA.
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If unsure, say N.
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config IMA_KEXEC
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bool "Enable carrying the IMA measurement list across a soft boot"
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depends on IMA && TCG_TPM && HAVE_IMA_KEXEC
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default n
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help
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TPM PCRs are only reset on a hard reboot. In order to validate
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a TPM's quote after a soft boot, the IMA measurement list of the
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running kernel must be saved and restored on boot.
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Depending on the IMA policy, the measurement list can grow to
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be very large.
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config IMA_MEASURE_PCR_IDX
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int
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depends on IMA
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range 8 14
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default 10
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help
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IMA_MEASURE_PCR_IDX determines the TPM PCR register index
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that IMA uses to maintain the integrity aggregate of the
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measurement list. If unsure, use the default 10.
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config IMA_LSM_RULES
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bool
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depends on IMA && AUDIT && (SECURITY_SELINUX || SECURITY_SMACK)
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default y
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help
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Disabling this option will disregard LSM based policy rules.
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choice
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prompt "Default template"
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default IMA_NG_TEMPLATE
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depends on IMA
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help
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Select the default IMA measurement template.
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The original 'ima' measurement list template contains a
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hash, defined as 20 bytes, and a null terminated pathname,
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limited to 255 characters. The 'ima-ng' measurement list
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template permits both larger hash digests and longer
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pathnames.
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config IMA_TEMPLATE
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bool "ima"
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config IMA_NG_TEMPLATE
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bool "ima-ng (default)"
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config IMA_SIG_TEMPLATE
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bool "ima-sig"
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endchoice
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config IMA_DEFAULT_TEMPLATE
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string
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depends on IMA
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default "ima" if IMA_TEMPLATE
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default "ima-ng" if IMA_NG_TEMPLATE
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default "ima-sig" if IMA_SIG_TEMPLATE
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choice
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prompt "Default integrity hash algorithm"
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default IMA_DEFAULT_HASH_SHA1
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depends on IMA
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help
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Select the default hash algorithm used for the measurement
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list, integrity appraisal and audit log. The compiled default
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hash algorithm can be overwritten using the kernel command
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line 'ima_hash=' option.
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config IMA_DEFAULT_HASH_SHA1
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bool "SHA1 (default)"
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depends on CRYPTO_SHA1=y
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config IMA_DEFAULT_HASH_SHA256
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bool "SHA256"
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depends on CRYPTO_SHA256=y && !IMA_TEMPLATE
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config IMA_DEFAULT_HASH_SHA512
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bool "SHA512"
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depends on CRYPTO_SHA512=y && !IMA_TEMPLATE
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config IMA_DEFAULT_HASH_WP512
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bool "WP512"
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depends on CRYPTO_WP512=y && !IMA_TEMPLATE
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endchoice
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config IMA_DEFAULT_HASH
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string
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depends on IMA
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default "sha1" if IMA_DEFAULT_HASH_SHA1
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default "sha256" if IMA_DEFAULT_HASH_SHA256
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default "sha512" if IMA_DEFAULT_HASH_SHA512
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default "wp512" if IMA_DEFAULT_HASH_WP512
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config IMA_WRITE_POLICY
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bool "Enable multiple writes to the IMA policy"
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depends on IMA
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default n
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help
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IMA policy can now be updated multiple times. The new rules get
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appended to the original policy. Have in mind that the rules are
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scanned in FIFO order so be careful when you design and add new ones.
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If unsure, say N.
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config IMA_READ_POLICY
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bool "Enable reading back the current IMA policy"
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depends on IMA
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default y if IMA_WRITE_POLICY
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default n if !IMA_WRITE_POLICY
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help
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It is often useful to be able to read back the IMA policy. It is
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even more important after introducing CONFIG_IMA_WRITE_POLICY.
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This option allows the root user to see the current policy rules.
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config IMA_APPRAISE
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bool "Appraise integrity measurements"
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depends on IMA
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default n
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help
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This option enables local measurement integrity appraisal.
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It requires the system to be labeled with a security extended
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attribute containing the file hash measurement. To protect
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the security extended attributes from offline attack, enable
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and configure EVM.
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For more information on integrity appraisal refer to:
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<http://linux-ima.sourceforge.net>
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If unsure, say N.
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config IMA_ARCH_POLICY
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bool "Enable loading an IMA architecture specific policy"
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depends on (KEXEC_SIG && IMA) || IMA_APPRAISE \
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&& INTEGRITY_ASYMMETRIC_KEYS
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default n
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help
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This option enables loading an IMA architecture specific policy
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based on run time secure boot flags.
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config IMA_APPRAISE_BUILD_POLICY
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bool "IMA build time configured policy rules"
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depends on IMA_APPRAISE && INTEGRITY_ASYMMETRIC_KEYS
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default n
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help
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This option defines an IMA appraisal policy at build time, which
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is enforced at run time without having to specify a builtin
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policy name on the boot command line. The build time appraisal
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policy rules persist after loading a custom policy.
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Depending on the rules configured, this policy may require kernel
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modules, firmware, the kexec kernel image, and/or the IMA policy
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to be signed. Unsigned files might prevent the system from
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booting or applications from working properly.
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config IMA_APPRAISE_REQUIRE_FIRMWARE_SIGS
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bool "Appraise firmware signatures"
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depends on IMA_APPRAISE_BUILD_POLICY
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default n
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help
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This option defines a policy requiring all firmware to be signed,
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including the regulatory.db. If both this option and
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CFG80211_REQUIRE_SIGNED_REGDB are enabled, then both signature
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verification methods are necessary.
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config IMA_APPRAISE_REQUIRE_KEXEC_SIGS
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bool "Appraise kexec kernel image signatures"
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depends on IMA_APPRAISE_BUILD_POLICY
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default n
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help
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Enabling this rule will require all kexec'ed kernel images to
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be signed and verified by a public key on the trusted IMA
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keyring.
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Kernel image signatures can not be verified by the original
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kexec_load syscall. Enabling this rule will prevent its
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usage.
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config IMA_APPRAISE_REQUIRE_MODULE_SIGS
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bool "Appraise kernel modules signatures"
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depends on IMA_APPRAISE_BUILD_POLICY
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default n
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help
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Enabling this rule will require all kernel modules to be signed
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and verified by a public key on the trusted IMA keyring.
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Kernel module signatures can only be verified by IMA-appraisal,
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via the finit_module syscall. Enabling this rule will prevent
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the usage of the init_module syscall.
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config IMA_APPRAISE_REQUIRE_POLICY_SIGS
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bool "Appraise IMA policy signature"
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depends on IMA_APPRAISE_BUILD_POLICY
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default n
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help
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Enabling this rule will require the IMA policy to be signed and
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and verified by a key on the trusted IMA keyring.
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config IMA_APPRAISE_BOOTPARAM
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bool "ima_appraise boot parameter"
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depends on IMA_APPRAISE && !IMA_ARCH_POLICY
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default y
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help
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This option enables the different "ima_appraise=" modes
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(eg. fix, log) from the boot command line.
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config IMA_APPRAISE_MODSIG
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bool "Support module-style signatures for appraisal"
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depends on IMA_APPRAISE
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depends on INTEGRITY_ASYMMETRIC_KEYS
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select PKCS7_MESSAGE_PARSER
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select MODULE_SIG_FORMAT
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default n
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help
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Adds support for signatures appended to files. The format of the
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appended signature is the same used for signed kernel modules.
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The modsig keyword can be used in the IMA policy to allow a hook
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to accept such signatures.
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config IMA_TRUSTED_KEYRING
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bool "Require all keys on the .ima keyring be signed (deprecated)"
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depends on IMA_APPRAISE && SYSTEM_TRUSTED_KEYRING
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depends on INTEGRITY_ASYMMETRIC_KEYS
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select INTEGRITY_TRUSTED_KEYRING
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default y
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help
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This option requires that all keys added to the .ima
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keyring be signed by a key on the system trusted keyring.
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This option is deprecated in favor of INTEGRITY_TRUSTED_KEYRING
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config IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY
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bool "Permit keys validly signed by a built-in or secondary CA cert (EXPERIMENTAL)"
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depends on SYSTEM_TRUSTED_KEYRING
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depends on SECONDARY_TRUSTED_KEYRING
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depends on INTEGRITY_ASYMMETRIC_KEYS
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select INTEGRITY_TRUSTED_KEYRING
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default n
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help
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Keys may be added to the IMA or IMA blacklist keyrings, if the
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key is validly signed by a CA cert in the system built-in or
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secondary trusted keyrings.
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Intermediate keys between those the kernel has compiled in and the
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IMA keys to be added may be added to the system secondary keyring,
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provided they are validly signed by a key already resident in the
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built-in or secondary trusted keyrings.
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config IMA_BLACKLIST_KEYRING
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bool "Create IMA machine owner blacklist keyrings (EXPERIMENTAL)"
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depends on SYSTEM_TRUSTED_KEYRING
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depends on IMA_TRUSTED_KEYRING
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default n
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help
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This option creates an IMA blacklist keyring, which contains all
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revoked IMA keys. It is consulted before any other keyring. If
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the search is successful the requested operation is rejected and
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an error is returned to the caller.
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config IMA_LOAD_X509
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bool "Load X509 certificate onto the '.ima' trusted keyring"
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depends on IMA_TRUSTED_KEYRING
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default n
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help
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File signature verification is based on the public keys
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loaded on the .ima trusted keyring. These public keys are
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X509 certificates signed by a trusted key on the
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.system keyring. This option enables X509 certificate
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loading from the kernel onto the '.ima' trusted keyring.
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config IMA_X509_PATH
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string "IMA X509 certificate path"
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depends on IMA_LOAD_X509
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default "/etc/keys/x509_ima.der"
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help
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This option defines IMA X509 certificate path.
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config IMA_APPRAISE_SIGNED_INIT
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bool "Require signed user-space initialization"
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depends on IMA_LOAD_X509
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default n
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help
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This option requires user-space init to be signed.
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