[mirror_ubuntu-zesty-kernel.git] / security / Kconfig

#
# 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 SECURITYFS
	bool "Enable the securityfs filesystem"
	help
	  This will build the securityfs filesystem.  It is currently used by
	  the TPM bios character driver and IMA, an integrity provider.  It is
	  not used by SELinux or SMACK.

	  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_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/intel_txt.txt 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 HAVE_ARCH_HARDENED_USERCOPY
	bool
	help
	  The architecture supports CONFIG_HARDENED_USERCOPY by
	  calling check_object_size() just before performing the
	  userspace copies in the low level implementation of
	  copy_to_user() and copy_from_user().

config HARDENED_USERCOPY
	bool "Harden memory copies between kernel and userspace"
	depends on HAVE_ARCH_HARDENED_USERCOPY
	depends on HAVE_HARDENED_USERCOPY_ALLOCATOR
	select BUG
	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 allocates 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_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.

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/integrity/Kconfig

choice
	prompt "Default security module"
	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
	  Select the security module that will be used by default if the
	  kernel parameter security= is not specified.

	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 DEFAULT_SECURITY
	string
	default "selinux" if DEFAULT_SECURITY_SELINUX
	default "smack" if DEFAULT_SECURITY_SMACK
	default "tomoyo" if DEFAULT_SECURITY_TOMOYO
	default "apparmor" if DEFAULT_SECURITY_APPARMOR
	default "" if DEFAULT_SECURITY_DAC

endmenu
Commit	Line	Data
1da177e4 LT	1	#
	2	# Security configuration
	3	#
	4
	5	menu "Security options"
	6
f0894940	7	source security/keys/Kconfig
1da177e4	8
eaf06b24 DR	9	config SECURITY_DMESG_RESTRICT
	10	bool "Restrict unprivileged access to the kernel syslog"
	11	default n
	12	help
	13	This enforces restrictions on unprivileged users reading the kernel
	14	syslog via dmesg(8).
	15
	16	If this option is not selected, no restrictions will be enforced
	17	unless the dmesg_restrict sysctl is explicitly set to (1).
	18
	19	If you are unsure how to answer this question, answer N.
	20
1da177e4 LT	21	config SECURITY
1da177e4 LT	22	bool "Enable different security models"
2c40579b	23	depends on SYSFS
2813893f	24	depends on MULTIUSER
1da177e4 LT	25	help
	26	This allows you to choose different security modules to be
	27	configured into your kernel.
	28
	29	If this option is not selected, the default Linux security
	30	model will be used.
	31
	32	If you are unsure how to answer this question, answer N.
	33
da31894e EP	34	config SECURITYFS
	35	bool "Enable the securityfs filesystem"
	36	help
	37	This will build the securityfs filesystem. It is currently used by
3323eec9 MZ	38	the TPM bios character driver and IMA, an integrity provider. It is
3323eec9 MZ	39	not used by SELinux or SMACK.
da31894e EP	40
	41	If you are unsure how to answer this question, answer N.
	42
1da177e4 LT	43	config SECURITY_NETWORK
	44	bool "Socket and Networking Security Hooks"
	45	depends on SECURITY
	46	help
	47	This enables the socket and networking security hooks.
	48	If enabled, a security module can use these hooks to
	49	implement socket and networking access controls.
	50	If you are unsure how to answer this question, answer N.
df71837d TJ	51
	52	config SECURITY_NETWORK_XFRM
	53	bool "XFRM (IPSec) Networking Security Hooks"
	54	depends on XFRM && SECURITY_NETWORK
	55	help
	56	This enables the XFRM (IPSec) networking security hooks.
	57	If enabled, a security module can use these hooks to
	58	implement per-packet access controls based on labels
	59	derived from IPSec policy. Non-IPSec communications are
	60	designated as unlabelled, and only sockets authorized
	61	to communicate unlabelled data can send without using
	62	IPSec.
	63	If you are unsure how to answer this question, answer N.
1da177e4	64
be6d3e56 KT	65	config SECURITY_PATH
	66	bool "Security hooks for pathname based access control"
	67	depends on SECURITY
	68	help
	69	This enables the security hooks for pathname based access control.
	70	If enabled, a security module can use these hooks to
	71	implement pathname based access controls.
	72	If you are unsure how to answer this question, answer N.
	73
31625340 JC	74	config INTEL_TXT
31625340 JC	75	bool "Enable Intel(R) Trusted Execution Technology (Intel(R) TXT)"
69575d38	76	depends on HAVE_INTEL_TXT
31625340 JC	77	help
	78	This option enables support for booting the kernel with the
	79	Trusted Boot (tboot) module. This will utilize
	80	Intel(R) Trusted Execution Technology to perform a measured launch
	81	of the kernel. If the system does not support Intel(R) TXT, this
	82	will have no effect.
	83
3c556e41	84	Intel TXT will provide higher assurance of system configuration and
31625340 JC	85	initial state as well as data reset protection. This is used to
	86	create a robust initial kernel measurement and verification, which
	87	helps to ensure that kernel security mechanisms are functioning
	88	correctly. This level of protection requires a root of trust outside
	89	of the kernel itself.
	90
	91	Intel TXT also helps solve real end user concerns about having
	92	confidence that their hardware is running the VMM or kernel that
3c556e41	93	it was configured with, especially since they may be responsible for
31625340 JC	94	providing such assurances to VMs and services running on it.
	95
	96	See <http://www.intel.com/technology/security/> for more information
	97	about Intel(R) TXT.
	98	See <http://tboot.sourceforge.net> for more information about tboot.
	99	See Documentation/intel_txt.txt for a description of how to enable
	100	Intel TXT support in a kernel boot.
	101
	102	If you are unsure as to whether this is required, answer N.
	103
788084ab	104	config LSM_MMAP_MIN_ADDR
024e6cb4	105	int "Low address space for LSM to protect from user allocation"
788084ab	106	depends on SECURITY && SECURITY_SELINUX
530b099d	107	default 32768 if ARM \|\| (ARM64 && COMPAT)
a58578e4	108	default 65536
788084ab EP	109	help
	110	This is the portion of low virtual memory which should be protected
	111	from userspace allocation. Keeping a user from writing to low pages
	112	can help reduce the impact of kernel NULL pointer bugs.
	113
	114	For most ia64, ppc64 and x86 users with lots of address space
	115	a value of 65536 is reasonable and should cause no problems.
	116	On arm and other archs it should not be higher than 32768.
	117	Programs which use vm86 functionality or have some need to map
	118	this low address space will need the permission specific to the
	119	systems running LSM.
	120
f5509cc1 KC	121	config HAVE_HARDENED_USERCOPY_ALLOCATOR
	122	bool
	123	help
	124	The heap allocator implements __check_heap_object() for
	125	validating memory ranges against heap object sizes in
	126	support of CONFIG_HARDENED_USERCOPY.
	127
	128	config HAVE_ARCH_HARDENED_USERCOPY
	129	bool
	130	help
	131	The architecture supports CONFIG_HARDENED_USERCOPY by
	132	calling check_object_size() just before performing the
	133	userspace copies in the low level implementation of
	134	copy_to_user() and copy_from_user().
	135
	136	config HARDENED_USERCOPY
	137	bool "Harden memory copies between kernel and userspace"
	138	depends on HAVE_ARCH_HARDENED_USERCOPY
6040e576	139	depends on HAVE_HARDENED_USERCOPY_ALLOCATOR
f5509cc1 KC	140	select BUG
	141	help
	142	This option checks for obviously wrong memory regions when
	143	copying memory to/from the kernel (via copy_to_user() and
	144	copy_from_user() functions) by rejecting memory ranges that
	145	are larger than the specified heap object, span multiple
	146	separately allocates pages, are not on the process stack,
	147	or are part of the kernel text. This kills entire classes
	148	of heap overflow exploits and similar kernel memory exposures.
	149
8e1f74ea KC	150	config HARDENED_USERCOPY_PAGESPAN
	151	bool "Refuse to copy allocations that span multiple pages"
	152	depends on HARDENED_USERCOPY
80a77045	153	depends on EXPERT
8e1f74ea KC	154	help
	155	When a multi-page allocation is done without __GFP_COMP,
	156	hardened usercopy will reject attempts to copy it. There are,
	157	however, several cases of this in the kernel that have not all
	158	been removed. This config is intended to be used only while
	159	trying to find such users.
	160
1da177e4	161	source security/selinux/Kconfig
e114e473	162	source security/smack/Kconfig
00d7d6f8	163	source security/tomoyo/Kconfig
f9ad1af5	164	source security/apparmor/Kconfig
9b091556	165	source security/loadpin/Kconfig
2d514487	166	source security/yama/Kconfig
1da177e4	167
f381c272	168	source security/integrity/Kconfig
3323eec9	169
6e65f92f JJ	170	choice
	171	prompt "Default security module"
	172	default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX
	173	default DEFAULT_SECURITY_SMACK if SECURITY_SMACK
	174	default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO
f9ad1af5	175	default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR
6e65f92f JJ	176	default DEFAULT_SECURITY_DAC
	177
	178	help
	179	Select the security module that will be used by default if the
	180	kernel parameter security= is not specified.
	181
	182	config DEFAULT_SECURITY_SELINUX
	183	bool "SELinux" if SECURITY_SELINUX=y
	184
	185	config DEFAULT_SECURITY_SMACK
	186	bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y
	187
	188	config DEFAULT_SECURITY_TOMOYO
	189	bool "TOMOYO" if SECURITY_TOMOYO=y
	190
f9ad1af5 JJ	191	config DEFAULT_SECURITY_APPARMOR
	192	bool "AppArmor" if SECURITY_APPARMOR=y
	193
6e65f92f JJ	194	config DEFAULT_SECURITY_DAC
	195	bool "Unix Discretionary Access Controls"
	196
	197	endchoice
	198
	199	config DEFAULT_SECURITY
	200	string
	201	default "selinux" if DEFAULT_SECURITY_SELINUX
	202	default "smack" if DEFAULT_SECURITY_SMACK
	203	default "tomoyo" if DEFAULT_SECURITY_TOMOYO
f9ad1af5	204	default "apparmor" if DEFAULT_SECURITY_APPARMOR
6e65f92f JJ	205	default "" if DEFAULT_SECURITY_DAC
6e65f92f JJ	206
1da177e4 LT	207	endmenu
1da177e4 LT	208