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Thomas Gleixnerec8f24b2019-05-19 13:07:45 +01001# SPDX-License-Identifier: GPL-2.0-only
Linus Torvalds1da177e2005-04-16 15:20:36 -07002#
3# Security configuration
4#
5
6menu "Security options"
7
Masahiro Yamada8636a1f2018-12-11 20:01:04 +09008source "security/keys/Kconfig"
Linus Torvalds1da177e2005-04-16 15:20:36 -07009
Dan Rosenbergeaf06b22010-11-11 14:05:18 -080010config SECURITY_DMESG_RESTRICT
11 bool "Restrict unprivileged access to the kernel syslog"
12 default n
13 help
14 This enforces restrictions on unprivileged users reading the kernel
15 syslog via dmesg(8).
16
17 If this option is not selected, no restrictions will be enforced
18 unless the dmesg_restrict sysctl is explicitly set to (1).
19
20 If you are unsure how to answer this question, answer N.
21
Linus Torvalds1da177e2005-04-16 15:20:36 -070022config SECURITY
23 bool "Enable different security models"
Adrian Bunk2c405792005-08-22 18:20:50 +020024 depends on SYSFS
Iulia Manda28138932015-04-15 16:16:41 -070025 depends on MULTIUSER
Linus Torvalds1da177e2005-04-16 15:20:36 -070026 help
27 This allows you to choose different security modules to be
28 configured into your kernel.
29
30 If this option is not selected, the default Linux security
31 model will be used.
32
33 If you are unsure how to answer this question, answer N.
34
James Morrisdd0859d2017-02-15 00:17:24 +110035config SECURITY_WRITABLE_HOOKS
36 depends on SECURITY
37 bool
38 default n
39
Eric Parisda318942008-08-22 11:35:57 -040040config SECURITYFS
41 bool "Enable the securityfs filesystem"
42 help
43 This will build the securityfs filesystem. It is currently used by
Petr Vorelb102c112019-03-01 00:54:48 +010044 various security modules (AppArmor, IMA, SafeSetID, TOMOYO, TPM).
Eric Parisda318942008-08-22 11:35:57 -040045
46 If you are unsure how to answer this question, answer N.
47
Linus Torvalds1da177e2005-04-16 15:20:36 -070048config SECURITY_NETWORK
49 bool "Socket and Networking Security Hooks"
50 depends on SECURITY
51 help
52 This enables the socket and networking security hooks.
53 If enabled, a security module can use these hooks to
54 implement socket and networking access controls.
55 If you are unsure how to answer this question, answer N.
56
Dave Hansen385ce0e2017-12-04 15:08:03 +010057config PAGE_TABLE_ISOLATION
58 bool "Remove the kernel mapping in user mode"
Thomas Gleixner87faa0d2018-01-03 15:18:44 +010059 default y
Joerg Roedel61a6bd82018-09-14 12:59:14 +020060 depends on (X86_64 || X86_PAE) && !UML
Dave Hansen385ce0e2017-12-04 15:08:03 +010061 help
62 This feature reduces the number of hardware side channels by
63 ensuring that the majority of kernel addresses are not mapped
64 into userspace.
65
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -030066 See Documentation/x86/pti.rst for more details.
Dave Hansen385ce0e2017-12-04 15:08:03 +010067
Daniel Jurgensd291f1a2017-05-19 15:48:52 +030068config SECURITY_INFINIBAND
69 bool "Infiniband Security Hooks"
70 depends on SECURITY && INFINIBAND
71 help
72 This enables the Infiniband security hooks.
73 If enabled, a security module can use these hooks to
74 implement Infiniband access controls.
75 If you are unsure how to answer this question, answer N.
76
Trent Jaegerdf718372005-12-13 23:12:27 -080077config SECURITY_NETWORK_XFRM
78 bool "XFRM (IPSec) Networking Security Hooks"
79 depends on XFRM && SECURITY_NETWORK
80 help
81 This enables the XFRM (IPSec) networking security hooks.
82 If enabled, a security module can use these hooks to
83 implement per-packet access controls based on labels
84 derived from IPSec policy. Non-IPSec communications are
85 designated as unlabelled, and only sockets authorized
86 to communicate unlabelled data can send without using
87 IPSec.
88 If you are unsure how to answer this question, answer N.
89
Kentaro Takedabe6d3e52008-12-17 13:24:15 +090090config SECURITY_PATH
91 bool "Security hooks for pathname based access control"
92 depends on SECURITY
93 help
94 This enables the security hooks for pathname based access control.
95 If enabled, a security module can use these hooks to
96 implement pathname based access controls.
97 If you are unsure how to answer this question, answer N.
98
Joseph Cihula31625342009-06-30 19:30:59 -070099config INTEL_TXT
100 bool "Enable Intel(R) Trusted Execution Technology (Intel(R) TXT)"
Shane Wang69575d32009-09-01 18:25:07 -0700101 depends on HAVE_INTEL_TXT
Joseph Cihula31625342009-06-30 19:30:59 -0700102 help
103 This option enables support for booting the kernel with the
104 Trusted Boot (tboot) module. This will utilize
105 Intel(R) Trusted Execution Technology to perform a measured launch
106 of the kernel. If the system does not support Intel(R) TXT, this
107 will have no effect.
108
Arnaldo Carvalho de Melo3c556e42009-08-12 12:00:40 -0300109 Intel TXT will provide higher assurance of system configuration and
Joseph Cihula31625342009-06-30 19:30:59 -0700110 initial state as well as data reset protection. This is used to
111 create a robust initial kernel measurement and verification, which
112 helps to ensure that kernel security mechanisms are functioning
113 correctly. This level of protection requires a root of trust outside
114 of the kernel itself.
115
116 Intel TXT also helps solve real end user concerns about having
117 confidence that their hardware is running the VMM or kernel that
Arnaldo Carvalho de Melo3c556e42009-08-12 12:00:40 -0300118 it was configured with, especially since they may be responsible for
Joseph Cihula31625342009-06-30 19:30:59 -0700119 providing such assurances to VMs and services running on it.
120
Alexander A. Klimovc9fecf52020-07-05 23:45:12 +0200121 See <https://www.intel.com/technology/security/> for more information
Joseph Cihula31625342009-06-30 19:30:59 -0700122 about Intel(R) TXT.
123 See <http://tboot.sourceforge.net> for more information about tboot.
Mauro Carvalho Chehabe8d776f2019-04-20 09:20:52 -0300124 See Documentation/x86/intel_txt.rst for a description of how to enable
Joseph Cihula31625342009-06-30 19:30:59 -0700125 Intel TXT support in a kernel boot.
126
127 If you are unsure as to whether this is required, answer N.
128
Eric Paris788084a2009-07-31 12:54:11 -0400129config LSM_MMAP_MIN_ADDR
Andreas Schwab024e6cb2009-08-18 22:14:29 +0200130 int "Low address space for LSM to protect from user allocation"
Eric Paris788084a2009-07-31 12:54:11 -0400131 depends on SECURITY && SECURITY_SELINUX
Colin Cross530b0992014-02-04 02:15:32 +0000132 default 32768 if ARM || (ARM64 && COMPAT)
Dave Jonesa58578e2009-08-18 13:47:37 -0400133 default 65536
Eric Paris788084a2009-07-31 12:54:11 -0400134 help
135 This is the portion of low virtual memory which should be protected
136 from userspace allocation. Keeping a user from writing to low pages
137 can help reduce the impact of kernel NULL pointer bugs.
138
139 For most ia64, ppc64 and x86 users with lots of address space
140 a value of 65536 is reasonable and should cause no problems.
141 On arm and other archs it should not be higher than 32768.
142 Programs which use vm86 functionality or have some need to map
143 this low address space will need the permission specific to the
144 systems running LSM.
145
Kees Cookf5509cc2016-06-07 11:05:33 -0700146config HAVE_HARDENED_USERCOPY_ALLOCATOR
147 bool
148 help
149 The heap allocator implements __check_heap_object() for
150 validating memory ranges against heap object sizes in
151 support of CONFIG_HARDENED_USERCOPY.
152
Kees Cookf5509cc2016-06-07 11:05:33 -0700153config HARDENED_USERCOPY
154 bool "Harden memory copies between kernel and userspace"
Linus Torvalds6040e572016-08-19 12:47:01 -0700155 depends on HAVE_HARDENED_USERCOPY_ALLOCATOR
Kees Cook22ec1a22017-12-01 13:19:39 -0800156 imply STRICT_DEVMEM
Kees Cookf5509cc2016-06-07 11:05:33 -0700157 help
158 This option checks for obviously wrong memory regions when
159 copying memory to/from the kernel (via copy_to_user() and
160 copy_from_user() functions) by rejecting memory ranges that
161 are larger than the specified heap object, span multiple
Geert Uytterhoeven99c55fb2017-05-02 20:27:41 +0200162 separately allocated pages, are not on the process stack,
Matthew Wilcox (Oracle)1109a5d2022-01-10 23:15:30 +0000163 or are part of the kernel text. This prevents entire classes
Kees Cookf5509cc2016-06-07 11:05:33 -0700164 of heap overflow exploits and similar kernel memory exposures.
165
Daniel Micay6974f0c2017-07-12 14:36:10 -0700166config FORTIFY_SOURCE
167 bool "Harden common str/mem functions against buffer overflows"
168 depends on ARCH_HAS_FORTIFY_SOURCE
Kees Cooka52f8a52021-05-12 21:51:10 -0700169 # https://bugs.llvm.org/show_bug.cgi?id=41459
Kees Cook281d0c92022-02-08 14:53:50 -0800170 depends on !CC_IS_CLANG || CLANG_VERSION >= 120001
171 # https://github.com/llvm/llvm-project/issues/53645
172 depends on !CC_IS_CLANG || !X86_32
Daniel Micay6974f0c2017-07-12 14:36:10 -0700173 help
174 Detect overflows of buffers in common string and memory functions
175 where the compiler can determine and validate the buffer sizes.
176
Greg Kroah-Hartman64e90a8a2017-01-16 16:22:39 +0100177config STATIC_USERMODEHELPER
178 bool "Force all usermode helper calls through a single binary"
179 help
180 By default, the kernel can call many different userspace
181 binary programs through the "usermode helper" kernel
182 interface. Some of these binaries are statically defined
183 either in the kernel code itself, or as a kernel configuration
184 option. However, some of these are dynamically created at
185 runtime, or can be modified after the kernel has started up.
186 To provide an additional layer of security, route all of these
187 calls through a single executable that can not have its name
188 changed.
189
190 Note, it is up to this single binary to then call the relevant
191 "real" usermode helper binary, based on the first argument
192 passed to it. If desired, this program can filter and pick
193 and choose what real programs are called.
194
195 If you wish for all usermode helper programs are to be
196 disabled, choose this option and then set
197 STATIC_USERMODEHELPER_PATH to an empty string.
198
199config STATIC_USERMODEHELPER_PATH
200 string "Path to the static usermode helper binary"
201 depends on STATIC_USERMODEHELPER
202 default "/sbin/usermode-helper"
203 help
204 The binary called by the kernel when any usermode helper
205 program is wish to be run. The "real" application's name will
206 be in the first argument passed to this program on the command
207 line.
208
209 If you wish for all usermode helper programs to be disabled,
210 specify an empty string here (i.e. "").
211
Masahiro Yamada8636a1f2018-12-11 20:01:04 +0900212source "security/selinux/Kconfig"
213source "security/smack/Kconfig"
214source "security/tomoyo/Kconfig"
215source "security/apparmor/Kconfig"
216source "security/loadpin/Kconfig"
217source "security/yama/Kconfig"
Micah Mortonaeca4e22019-01-16 07:46:06 -0800218source "security/safesetid/Kconfig"
Matthew Garrett000d3882019-08-19 17:17:39 -0700219source "security/lockdown/Kconfig"
Mickaël Salaün90945442021-04-22 17:41:11 +0200220source "security/landlock/Kconfig"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221
Masahiro Yamada8636a1f2018-12-11 20:01:04 +0900222source "security/integrity/Kconfig"
Mimi Zohar3323eec2009-02-04 09:06:58 -0500223
Kees Cook2623c4f2019-03-29 12:36:04 -0700224choice
225 prompt "First legacy 'major LSM' to be initialized"
226 default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX
227 default DEFAULT_SECURITY_SMACK if SECURITY_SMACK
228 default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO
229 default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR
230 default DEFAULT_SECURITY_DAC
231
232 help
233 This choice is there only for converting CONFIG_DEFAULT_SECURITY
234 in old kernel configs to CONFIG_LSM in new kernel configs. Don't
235 change this choice unless you are creating a fresh kernel config,
236 for this choice will be ignored after CONFIG_LSM has been set.
237
238 Selects the legacy "major security module" that will be
239 initialized first. Overridden by non-default CONFIG_LSM.
240
241 config DEFAULT_SECURITY_SELINUX
242 bool "SELinux" if SECURITY_SELINUX=y
243
244 config DEFAULT_SECURITY_SMACK
245 bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y
246
247 config DEFAULT_SECURITY_TOMOYO
248 bool "TOMOYO" if SECURITY_TOMOYO=y
249
250 config DEFAULT_SECURITY_APPARMOR
251 bool "AppArmor" if SECURITY_APPARMOR=y
252
253 config DEFAULT_SECURITY_DAC
254 bool "Unix Discretionary Access Controls"
255
256endchoice
257
Kees Cook13e735c2018-10-09 14:27:46 -0700258config LSM
259 string "Ordered list of enabled LSMs"
Mickaël Salaün385975d2021-04-22 17:41:13 +0200260 default "landlock,lockdown,yama,loadpin,safesetid,integrity,smack,selinux,tomoyo,apparmor,bpf" if DEFAULT_SECURITY_SMACK
261 default "landlock,lockdown,yama,loadpin,safesetid,integrity,apparmor,selinux,smack,tomoyo,bpf" if DEFAULT_SECURITY_APPARMOR
262 default "landlock,lockdown,yama,loadpin,safesetid,integrity,tomoyo,bpf" if DEFAULT_SECURITY_TOMOYO
263 default "landlock,lockdown,yama,loadpin,safesetid,integrity,bpf" if DEFAULT_SECURITY_DAC
264 default "landlock,lockdown,yama,loadpin,safesetid,integrity,selinux,smack,tomoyo,apparmor,bpf"
Kees Cook13e735c2018-10-09 14:27:46 -0700265 help
266 A comma-separated list of LSMs, in initialization order.
Kees Cook79f78652018-09-19 17:30:09 -0700267 Any LSMs left off this list will be ignored. This can be
268 controlled at boot with the "lsm=" parameter.
Kees Cook13e735c2018-10-09 14:27:46 -0700269
270 If unsure, leave this as the default.
271
Kees Cook9f671e52019-04-10 08:23:44 -0700272source "security/Kconfig.hardening"
273
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274endmenu
275