# SPDX-License-Identifier: GPL-2.0-only
#
# Security configuration
#

menu "Security options"

source "security/keys/Kconfig"

config SECURITY_DMESG_RESTRICT
	bool "Restrict unprivileged access to the kernel syslog"
	default n
	help
	 This enforces restrictions on unprivileged users reading the kernel
	 syslog via dmesg(8).

	 If this option is not selected, no restrictions will be enforced
	 unless the dmesg_restrict sysctl is explicitly set to (1).

	 If you are unsure how to answer this question, answer N.

choice
	prompt "Allow /proc/pid/mem access override"
	default PROC_MEM_ALWAYS_FORCE
	help
	 Traditionally /proc/pid/mem allows users to override memory
	 permissions for users like ptrace, assuming they have ptrace
	 capability.

	 This allows people to limit that - either never override, or
	 require actual active ptrace attachment.

	 Defaults to the traditional behavior (for now)

config PROC_MEM_ALWAYS_FORCE
	bool "Traditional /proc/pid/mem behavior"
	help
	 This allows /proc/pid/mem accesses to override memory mapping
	 permissions if you have ptrace access rights.

config PROC_MEM_FORCE_PTRACE
	bool "Require active ptrace() use for access override"
	help
	 This allows /proc/pid/mem accesses to override memory mapping
	 permissions for active ptracers like gdb.

config PROC_MEM_NO_FORCE
	bool "Never"
	help
	 Never override memory mapping permissions

endchoice

config MSEAL_SYSTEM_MAPPINGS
	bool "mseal system mappings"
	depends on 64BIT
	depends on ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS
	depends on !CHECKPOINT_RESTORE
	help
	 Apply mseal on system mappings.
	 The system mappings includes vdso, vvar, vvar_vclock,
	 vectors (arm compat-mode), sigpage (arm compat-mode), uprobes.

	 A 64-bit kernel is required for the memory sealing feature.
	 No specific hardware features from the CPU are needed.

	 WARNING: This feature breaks programs which rely on relocating
	 or unmapping system mappings. Known broken software at the time
	 of writing includes CHECKPOINT_RESTORE, UML, gVisor, rr. Therefore
	 this config can't be enabled universally.

	 For complete descriptions of memory sealing, please see
	 Documentation/userspace-api/mseal.rst

config SECURITY
	bool "Enable different security models"
	depends on SYSFS
	depends on MULTIUSER
	help
	 This allows you to choose different security modules to be
	 configured into your kernel.

	 If this option is not selected, the default Linux security
	 model will be used.

	 If you are unsure how to answer this question, answer N.

config HAS_SECURITY_AUDIT
	def_bool y
	depends on AUDIT
	depends on SECURITY

config SECURITYFS
	bool "Enable the securityfs filesystem"
	help
	 This will build the securityfs filesystem. It is currently used by
	 various security modules (AppArmor, IMA, SafeSetID, TOMOYO, TPM).

	 If you are unsure how to answer this question, answer N.

config SECURITY_NETWORK
	bool "Socket and Networking Security Hooks"
	depends on SECURITY
	help
	 This enables the socket and networking security hooks.
	 If enabled, a security module can use these hooks to
	 implement socket and networking access controls.
	 If you are unsure how to answer this question, answer N.

config SECURITY_INFINIBAND
	bool "Infiniband Security Hooks"
	depends on SECURITY && INFINIBAND
	help
	 This enables the Infiniband security hooks.
	 If enabled, a security module can use these hooks to
	 implement Infiniband access controls.
	 If you are unsure how to answer this question, answer N.

config SECURITY_NETWORK_XFRM
	bool "XFRM (IPSec) Networking Security Hooks"
	depends on XFRM && SECURITY_NETWORK
	help
	 This enables the XFRM (IPSec) networking security hooks.
	 If enabled, a security module can use these hooks to
	 implement per-packet access controls based on labels
	 derived from IPSec policy. Non-IPSec communications are
	 designated as unlabelled, and only sockets authorized
	 to communicate unlabelled data can send without using
	 IPSec.
	 If you are unsure how to answer this question, answer N.

config SECURITY_PATH
	bool "Security hooks for pathname based access control"
	depends on SECURITY
	help
	 This enables the security hooks for pathname based access control.
	 If enabled, a security module can use these hooks to
	 implement pathname based access controls.
	 If you are unsure how to answer this question, answer N.

config INTEL_TXT
	bool "Enable Intel(R) Trusted Execution Technology (Intel(R) TXT)"
	depends on HAVE_INTEL_TXT
	help
	 This option enables support for booting the kernel with the
	 Trusted Boot (tboot) module. This will utilize
	 Intel(R) Trusted Execution Technology to perform a measured launch
	 of the kernel. If the system does not support Intel(R) TXT, this
	 will have no effect.

	 Intel TXT will provide higher assurance of system configuration and
	 initial state as well as data reset protection. This is used to
	 create a robust initial kernel measurement and verification, which
	 helps to ensure that kernel security mechanisms are functioning
	 correctly. This level of protection requires a root of trust outside
	 of the kernel itself.

	 Intel TXT also helps solve real end user concerns about having
	 confidence that their hardware is running the VMM or kernel that
	 it was configured with, especially since they may be responsible for
	 providing such assurances to VMs and services running on it.

	 See <https://www.intel.com/technology/security/> for more information
	 about Intel(R) TXT.
	 See <http://tboot.sourceforge.net> for more information about tboot.
	 See Documentation/arch/x86/intel_txt.rst for a description of how to enable
	 Intel TXT support in a kernel boot.

	 If you are unsure as to whether this is required, answer N.

config LSM_MMAP_MIN_ADDR
	int "Low address space for LSM to protect from user allocation"
	depends on SECURITY && SECURITY_SELINUX
	default 32768 if ARM || (ARM64 && COMPAT)
	default 65536
	help
	 This is the portion of low virtual memory which should be protected
	 from userspace allocation. Keeping a user from writing to low pages
	 can help reduce the impact of kernel NULL pointer bugs.

	 For most ia64, ppc64 and x86 users with lots of address space
	 a value of 65536 is reasonable and should cause no problems.
	 On arm and other archs it should not be higher than 32768.
	 Programs which use vm86 functionality or have some need to map
	 this low address space will need the permission specific to the
	 systems running LSM.

config STATIC_USERMODEHELPER
	bool "Force all usermode helper calls through a single binary"
	help
	 By default, the kernel can call many different userspace
	 binary programs through the "usermode helper" kernel
	 interface. Some of these binaries are statically defined
	 either in the kernel code itself, or as a kernel configuration
	 option. However, some of these are dynamically created at
	 runtime, or can be modified after the kernel has started up.
	 To provide an additional layer of security, route all of these
	 calls through a single executable that can not have its name
	 changed.

	 Note, it is up to this single binary to then call the relevant
	 "real" usermode helper binary, based on the first argument
	 passed to it. If desired, this program can filter and pick
	 and choose what real programs are called.

	 If you wish for all usermode helper programs are to be
	 disabled, choose this option and then set
	 STATIC_USERMODEHELPER_PATH to an empty string.

config STATIC_USERMODEHELPER_PATH
	string "Path to the static usermode helper binary"
	depends on STATIC_USERMODEHELPER
	default "/sbin/usermode-helper"
	help
	 The binary called by the kernel when any usermode helper
	 program is wish to be run. The "real" application's name will
	 be in the first argument passed to this program on the command
	 line.

	 If you wish for all usermode helper programs to be disabled,
	 specify an empty string here (i.e. "").

source "security/selinux/Kconfig"
source "security/smack/Kconfig"
source "security/tomoyo/Kconfig"
source "security/apparmor/Kconfig"
source "security/loadpin/Kconfig"
source "security/yama/Kconfig"
source "security/safesetid/Kconfig"
source "security/lockdown/Kconfig"
source "security/landlock/Kconfig"
source "security/ipe/Kconfig"

source "security/integrity/Kconfig"

choice
	prompt "First legacy 'major LSM' to be initialized"
	default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX
	default DEFAULT_SECURITY_SMACK if SECURITY_SMACK
	default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO
	default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR
	default DEFAULT_SECURITY_DAC

	help
	 This choice is there only for converting CONFIG_DEFAULT_SECURITY
	 in old kernel configs to CONFIG_LSM in new kernel configs. Don't
	 change this choice unless you are creating a fresh kernel config,
	 for this choice will be ignored after CONFIG_LSM has been set.

	 Selects the legacy "major security module" that will be
	 initialized first. Overridden by non-default CONFIG_LSM.

	config DEFAULT_SECURITY_SELINUX
		bool "SELinux" if SECURITY_SELINUX=y

	config DEFAULT_SECURITY_SMACK
		bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y

	config DEFAULT_SECURITY_TOMOYO
		bool "TOMOYO" if SECURITY_TOMOYO=y

	config DEFAULT_SECURITY_APPARMOR
		bool "AppArmor" if SECURITY_APPARMOR=y

	config DEFAULT_SECURITY_DAC
		bool "Unix Discretionary Access Controls"

endchoice

config LSM
	string "Ordered list of enabled LSMs"
	default "landlock,lockdown,yama,loadpin,safesetid,smack,selinux,tomoyo,apparmor,ipe,bpf" if DEFAULT_SECURITY_SMACK
	default "landlock,lockdown,yama,loadpin,safesetid,apparmor,selinux,smack,tomoyo,ipe,bpf" if DEFAULT_SECURITY_APPARMOR
	default "landlock,lockdown,yama,loadpin,safesetid,tomoyo,ipe,bpf" if DEFAULT_SECURITY_TOMOYO
	default "landlock,lockdown,yama,loadpin,safesetid,ipe,bpf" if DEFAULT_SECURITY_DAC
	default "landlock,lockdown,yama,loadpin,safesetid,selinux,smack,tomoyo,apparmor,ipe,bpf"
	help
	 A comma-separated list of LSMs, in initialization order.
	 Any LSMs left off this list, except for those with order
	 LSM_ORDER_FIRST and LSM_ORDER_LAST, which are always enabled
	 if selected in the kernel configuration, will be ignored.
	 This can be controlled at boot with the "lsm=" parameter.

	 If unsure, leave this as the default.

source "security/Kconfig.hardening"

endmenu