security/Kconfig - kernel/msm-5.4 - Gitiles

 # 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.

 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 SECURITY_WRITABLE_HOOKS
 	depends on SECURITY
 	bool
 	default n

 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 PAGE_TABLE_ISOLATION
 	bool "Remove the kernel mapping in user mode"
 	default y
 	depends on (X86_64 || X86_PAE) && !UML
 	help
 	  This feature reduces the number of hardware side channels by
 	  ensuring that the majority of kernel addresses are not mapped
 	  into userspace.

 	  See Documentation/x86/pti.rst for more details.

 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 <http://www.intel.com/technology/security/> for more information
 	  about Intel(R) TXT.
 	  See <http://tboot.sourceforge.net> for more information about tboot.
 	  See Documentation/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 HAVE_HARDENED_USERCOPY_ALLOCATOR
 	bool
 	help
 	  The heap allocator implements __check_heap_object() for
 	  validating memory ranges against heap object sizes in
 	  support of CONFIG_HARDENED_USERCOPY.

 config HARDENED_USERCOPY
 	bool "Harden memory copies between kernel and userspace"
 	depends on HAVE_HARDENED_USERCOPY_ALLOCATOR
 	imply STRICT_DEVMEM
 	help
 	  This option checks for obviously wrong memory regions when
 	  copying memory to/from the kernel (via copy_to_user() and
 	  copy_from_user() functions) by rejecting memory ranges that
 	  are larger than the specified heap object, span multiple
 	  separately allocated pages, are not on the process stack,
 	  or are part of the kernel text. This kills entire classes
 	  of heap overflow exploits and similar kernel memory exposures.

 config HARDENED_USERCOPY_FALLBACK
 	bool "Allow usercopy whitelist violations to fallback to object size"
 	depends on HARDENED_USERCOPY
 	default y
 	help
 	  This is a temporary option that allows missing usercopy whitelists
 	  to be discovered via a WARN() to the kernel log, instead of
 	  rejecting the copy, falling back to non-whitelisted hardened
 	  usercopy that checks the slab allocation size instead of the
 	  whitelist size. This option will be removed once it seems like
 	  all missing usercopy whitelists have been identified and fixed.
 	  Booting with "slab_common.usercopy_fallback=Y/N" can change
 	  this setting.

 config HARDENED_USERCOPY_PAGESPAN
 	bool "Refuse to copy allocations that span multiple pages"
 	depends on HARDENED_USERCOPY
 	depends on EXPERT
 	help
 	  When a multi-page allocation is done without __GFP_COMP,
 	  hardened usercopy will reject attempts to copy it. There are,
 	  however, several cases of this in the kernel that have not all
 	  been removed. This config is intended to be used only while
 	  trying to find such users.

 config FORTIFY_SOURCE
 	bool "Harden common str/mem functions against buffer overflows"
 	depends on ARCH_HAS_FORTIFY_SOURCE
 	help
 	  Detect overflows of buffers in common string and memory functions
 	  where the compiler can determine and validate the buffer sizes.

 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/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 "yama,loadpin,safesetid,integrity,smack,selinux,tomoyo,apparmor" if DEFAULT_SECURITY_SMACK
 	default "yama,loadpin,safesetid,integrity,apparmor,selinux,smack,tomoyo" if DEFAULT_SECURITY_APPARMOR
 	default "yama,loadpin,safesetid,integrity,tomoyo" if DEFAULT_SECURITY_TOMOYO
 	default "yama,loadpin,safesetid,integrity" if DEFAULT_SECURITY_DAC
 	default "yama,loadpin,safesetid,integrity,selinux,smack,tomoyo,apparmor"
 	help
 	  A comma-separated list of LSMs, in initialization order.
 	  Any LSMs left off this list 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
	# 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.

	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 SECURITY_WRITABLE_HOOKS
	depends on SECURITY
	bool
	default n

	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 PAGE_TABLE_ISOLATION
	bool "Remove the kernel mapping in user mode"
	default y
	depends on (X86_64 \|\| X86_PAE) && !UML
	help
	This feature reduces the number of hardware side channels by
	ensuring that the majority of kernel addresses are not mapped
	into userspace.

	See Documentation/x86/pti.rst for more details.

	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 <http://www.intel.com/technology/security/> for more information
	about Intel(R) TXT.
	See <http://tboot.sourceforge.net> for more information about tboot.
	See Documentation/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 HAVE_HARDENED_USERCOPY_ALLOCATOR
	bool
	help
	The heap allocator implements __check_heap_object() for
	validating memory ranges against heap object sizes in
	support of CONFIG_HARDENED_USERCOPY.

	config HARDENED_USERCOPY
	bool "Harden memory copies between kernel and userspace"
	depends on HAVE_HARDENED_USERCOPY_ALLOCATOR
	imply STRICT_DEVMEM
	help
	This option checks for obviously wrong memory regions when
	copying memory to/from the kernel (via copy_to_user() and
	copy_from_user() functions) by rejecting memory ranges that
	are larger than the specified heap object, span multiple
	separately allocated pages, are not on the process stack,
	or are part of the kernel text. This kills entire classes
	of heap overflow exploits and similar kernel memory exposures.

	config HARDENED_USERCOPY_FALLBACK
	bool "Allow usercopy whitelist violations to fallback to object size"
	depends on HARDENED_USERCOPY
	default y
	help
	This is a temporary option that allows missing usercopy whitelists
	to be discovered via a WARN() to the kernel log, instead of
	rejecting the copy, falling back to non-whitelisted hardened
	usercopy that checks the slab allocation size instead of the
	whitelist size. This option will be removed once it seems like
	all missing usercopy whitelists have been identified and fixed.
	Booting with "slab_common.usercopy_fallback=Y/N" can change
	this setting.

	config HARDENED_USERCOPY_PAGESPAN
	bool "Refuse to copy allocations that span multiple pages"
	depends on HARDENED_USERCOPY
	depends on EXPERT
	help
	When a multi-page allocation is done without __GFP_COMP,
	hardened usercopy will reject attempts to copy it. There are,
	however, several cases of this in the kernel that have not all
	been removed. This config is intended to be used only while
	trying to find such users.

	config FORTIFY_SOURCE
	bool "Harden common str/mem functions against buffer overflows"
	depends on ARCH_HAS_FORTIFY_SOURCE
	help
	Detect overflows of buffers in common string and memory functions
	where the compiler can determine and validate the buffer sizes.

	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/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 "yama,loadpin,safesetid,integrity,smack,selinux,tomoyo,apparmor" if DEFAULT_SECURITY_SMACK
	default "yama,loadpin,safesetid,integrity,apparmor,selinux,smack,tomoyo" if DEFAULT_SECURITY_APPARMOR
	default "yama,loadpin,safesetid,integrity,tomoyo" if DEFAULT_SECURITY_TOMOYO
	default "yama,loadpin,safesetid,integrity" if DEFAULT_SECURITY_DAC
	default "yama,loadpin,safesetid,integrity,selinux,smack,tomoyo,apparmor"
	help
	A comma-separated list of LSMs, in initialization order.
	Any LSMs left off this list 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