1 # SPDX-License-Identifier: GPL-2.0-only <<
2 # 1 #
3 # Security configuration 2 # Security configuration
4 # 3 #
5 4
6 menu "Security options" 5 menu "Security options"
7 6
8 source "security/keys/Kconfig" 7 source "security/keys/Kconfig"
9 8
10 config SECURITY_DMESG_RESTRICT 9 config SECURITY_DMESG_RESTRICT
11 bool "Restrict unprivileged access to 10 bool "Restrict unprivileged access to the kernel syslog"
12 default n 11 default n
13 help 12 help
14 This enforces restrictions on unpriv 13 This enforces restrictions on unprivileged users reading the kernel
15 syslog via dmesg(8). 14 syslog via dmesg(8).
16 15
17 If this option is not selected, no r 16 If this option is not selected, no restrictions will be enforced
18 unless the dmesg_restrict sysctl is 17 unless the dmesg_restrict sysctl is explicitly set to (1).
19 18
20 If you are unsure how to answer this 19 If you are unsure how to answer this question, answer N.
21 20
22 choice <<
23 prompt "Allow /proc/pid/mem access ove <<
24 default PROC_MEM_ALWAYS_FORCE <<
25 help <<
26 Traditionally /proc/pid/mem allows u <<
27 permissions for users like ptrace, a <<
28 capability. <<
29 <<
30 This allows people to limit that - e <<
31 require actual active ptrace attachm <<
32 <<
33 Defaults to the traditional behavior <<
34 <<
35 config PROC_MEM_ALWAYS_FORCE <<
36 bool "Traditional /proc/pid/mem behavi <<
37 help <<
38 This allows /proc/pid/mem accesses t <<
39 permissions if you have ptrace acces <<
40 <<
41 config PROC_MEM_FORCE_PTRACE <<
42 bool "Require active ptrace() use for <<
43 help <<
44 This allows /proc/pid/mem accesses t <<
45 permissions for active ptracers like <<
46 <<
47 config PROC_MEM_NO_FORCE <<
48 bool "Never" <<
49 help <<
50 Never override memory mapping permis <<
51 <<
52 endchoice <<
53 <<
54 config SECURITY 21 config SECURITY
55 bool "Enable different security models 22 bool "Enable different security models"
56 depends on SYSFS 23 depends on SYSFS
57 depends on MULTIUSER 24 depends on MULTIUSER
58 help 25 help
59 This allows you to choose different 26 This allows you to choose different security modules to be
60 configured into your kernel. 27 configured into your kernel.
61 28
62 If this option is not selected, the 29 If this option is not selected, the default Linux security
63 model will be used. 30 model will be used.
64 31
65 If you are unsure how to answer this 32 If you are unsure how to answer this question, answer N.
66 33
>> 34 config SECURITY_WRITABLE_HOOKS
>> 35 depends on SECURITY
>> 36 bool
>> 37 default n
>> 38
67 config SECURITYFS 39 config SECURITYFS
68 bool "Enable the securityfs filesystem 40 bool "Enable the securityfs filesystem"
69 help 41 help
70 This will build the securityfs files 42 This will build the securityfs filesystem. It is currently used by
71 various security modules (AppArmor, 43 various security modules (AppArmor, IMA, SafeSetID, TOMOYO, TPM).
72 44
73 If you are unsure how to answer this 45 If you are unsure how to answer this question, answer N.
74 46
75 config SECURITY_NETWORK 47 config SECURITY_NETWORK
76 bool "Socket and Networking Security H 48 bool "Socket and Networking Security Hooks"
77 depends on SECURITY 49 depends on SECURITY
78 help 50 help
79 This enables the socket and networki 51 This enables the socket and networking security hooks.
80 If enabled, a security module can us 52 If enabled, a security module can use these hooks to
81 implement socket and networking acce 53 implement socket and networking access controls.
82 If you are unsure how to answer this 54 If you are unsure how to answer this question, answer N.
83 55
>> 56 config PAGE_TABLE_ISOLATION
>> 57 bool "Remove the kernel mapping in user mode"
>> 58 default y
>> 59 depends on (X86_64 || X86_PAE) && !UML
>> 60 help
>> 61 This feature reduces the number of hardware side channels by
>> 62 ensuring that the majority of kernel addresses are not mapped
>> 63 into userspace.
>> 64
>> 65 See Documentation/x86/pti.txt for more details.
>> 66
84 config SECURITY_INFINIBAND 67 config SECURITY_INFINIBAND
85 bool "Infiniband Security Hooks" 68 bool "Infiniband Security Hooks"
86 depends on SECURITY && INFINIBAND 69 depends on SECURITY && INFINIBAND
87 help 70 help
88 This enables the Infiniband security 71 This enables the Infiniband security hooks.
89 If enabled, a security module can us 72 If enabled, a security module can use these hooks to
90 implement Infiniband access controls 73 implement Infiniband access controls.
91 If you are unsure how to answer this 74 If you are unsure how to answer this question, answer N.
92 75
93 config SECURITY_NETWORK_XFRM 76 config SECURITY_NETWORK_XFRM
94 bool "XFRM (IPSec) Networking Security 77 bool "XFRM (IPSec) Networking Security Hooks"
95 depends on XFRM && SECURITY_NETWORK 78 depends on XFRM && SECURITY_NETWORK
96 help 79 help
97 This enables the XFRM (IPSec) networ 80 This enables the XFRM (IPSec) networking security hooks.
98 If enabled, a security module can us 81 If enabled, a security module can use these hooks to
99 implement per-packet access controls 82 implement per-packet access controls based on labels
100 derived from IPSec policy. Non-IPSe 83 derived from IPSec policy. Non-IPSec communications are
101 designated as unlabelled, and only s 84 designated as unlabelled, and only sockets authorized
102 to communicate unlabelled data can s 85 to communicate unlabelled data can send without using
103 IPSec. 86 IPSec.
104 If you are unsure how to answer this 87 If you are unsure how to answer this question, answer N.
105 88
106 config SECURITY_PATH 89 config SECURITY_PATH
107 bool "Security hooks for pathname base 90 bool "Security hooks for pathname based access control"
108 depends on SECURITY 91 depends on SECURITY
109 help 92 help
110 This enables the security hooks for 93 This enables the security hooks for pathname based access control.
111 If enabled, a security module can us 94 If enabled, a security module can use these hooks to
112 implement pathname based access cont 95 implement pathname based access controls.
113 If you are unsure how to answer this 96 If you are unsure how to answer this question, answer N.
114 97
115 config INTEL_TXT 98 config INTEL_TXT
116 bool "Enable Intel(R) Trusted Executio 99 bool "Enable Intel(R) Trusted Execution Technology (Intel(R) TXT)"
117 depends on HAVE_INTEL_TXT 100 depends on HAVE_INTEL_TXT
118 help 101 help
119 This option enables support for boot 102 This option enables support for booting the kernel with the
120 Trusted Boot (tboot) module. This wi 103 Trusted Boot (tboot) module. This will utilize
121 Intel(R) Trusted Execution Technolog 104 Intel(R) Trusted Execution Technology to perform a measured launch
122 of the kernel. If the system does no 105 of the kernel. If the system does not support Intel(R) TXT, this
123 will have no effect. 106 will have no effect.
124 107
125 Intel TXT will provide higher assura 108 Intel TXT will provide higher assurance of system configuration and
126 initial state as well as data reset 109 initial state as well as data reset protection. This is used to
127 create a robust initial kernel measu 110 create a robust initial kernel measurement and verification, which
128 helps to ensure that kernel security 111 helps to ensure that kernel security mechanisms are functioning
129 correctly. This level of protection 112 correctly. This level of protection requires a root of trust outside
130 of the kernel itself. 113 of the kernel itself.
131 114
132 Intel TXT also helps solve real end 115 Intel TXT also helps solve real end user concerns about having
133 confidence that their hardware is ru 116 confidence that their hardware is running the VMM or kernel that
134 it was configured with, especially s 117 it was configured with, especially since they may be responsible for
135 providing such assurances to VMs and 118 providing such assurances to VMs and services running on it.
136 119
137 See <https://www.intel.com/technolog !! 120 See <http://www.intel.com/technology/security/> for more information
138 about Intel(R) TXT. 121 about Intel(R) TXT.
139 See <http://tboot.sourceforge.net> f 122 See <http://tboot.sourceforge.net> for more information about tboot.
140 See Documentation/arch/x86/intel_txt !! 123 See Documentation/intel_txt.txt for a description of how to enable
141 Intel TXT support in a kernel boot. 124 Intel TXT support in a kernel boot.
142 125
143 If you are unsure as to whether this 126 If you are unsure as to whether this is required, answer N.
144 127
145 config LSM_MMAP_MIN_ADDR 128 config LSM_MMAP_MIN_ADDR
146 int "Low address space for LSM to prot 129 int "Low address space for LSM to protect from user allocation"
147 depends on SECURITY && SECURITY_SELINU 130 depends on SECURITY && SECURITY_SELINUX
148 default 32768 if ARM || (ARM64 && COMP 131 default 32768 if ARM || (ARM64 && COMPAT)
149 default 65536 132 default 65536
150 help 133 help
151 This is the portion of low virtual m 134 This is the portion of low virtual memory which should be protected
152 from userspace allocation. Keeping 135 from userspace allocation. Keeping a user from writing to low pages
153 can help reduce the impact of kernel 136 can help reduce the impact of kernel NULL pointer bugs.
154 137
155 For most ia64, ppc64 and x86 users w 138 For most ia64, ppc64 and x86 users with lots of address space
156 a value of 65536 is reasonable and s 139 a value of 65536 is reasonable and should cause no problems.
157 On arm and other archs it should not 140 On arm and other archs it should not be higher than 32768.
158 Programs which use vm86 functionalit 141 Programs which use vm86 functionality or have some need to map
159 this low address space will need the 142 this low address space will need the permission specific to the
160 systems running LSM. 143 systems running LSM.
161 144
>> 145 config HAVE_HARDENED_USERCOPY_ALLOCATOR
>> 146 bool
>> 147 help
>> 148 The heap allocator implements __check_heap_object() for
>> 149 validating memory ranges against heap object sizes in
>> 150 support of CONFIG_HARDENED_USERCOPY.
>> 151
162 config HARDENED_USERCOPY 152 config HARDENED_USERCOPY
163 bool "Harden memory copies between ker 153 bool "Harden memory copies between kernel and userspace"
>> 154 depends on HAVE_HARDENED_USERCOPY_ALLOCATOR
164 imply STRICT_DEVMEM 155 imply STRICT_DEVMEM
165 help 156 help
166 This option checks for obviously wro 157 This option checks for obviously wrong memory regions when
167 copying memory to/from the kernel (v 158 copying memory to/from the kernel (via copy_to_user() and
168 copy_from_user() functions) by rejec 159 copy_from_user() functions) by rejecting memory ranges that
169 are larger than the specified heap o 160 are larger than the specified heap object, span multiple
170 separately allocated pages, are not 161 separately allocated pages, are not on the process stack,
171 or are part of the kernel text. This !! 162 or are part of the kernel text. This kills entire classes
172 of heap overflow exploits and simila 163 of heap overflow exploits and similar kernel memory exposures.
173 164
>> 165 config HARDENED_USERCOPY_FALLBACK
>> 166 bool "Allow usercopy whitelist violations to fallback to object size"
>> 167 depends on HARDENED_USERCOPY
>> 168 default y
>> 169 help
>> 170 This is a temporary option that allows missing usercopy whitelists
>> 171 to be discovered via a WARN() to the kernel log, instead of
>> 172 rejecting the copy, falling back to non-whitelisted hardened
>> 173 usercopy that checks the slab allocation size instead of the
>> 174 whitelist size. This option will be removed once it seems like
>> 175 all missing usercopy whitelists have been identified and fixed.
>> 176 Booting with "slab_common.usercopy_fallback=Y/N" can change
>> 177 this setting.
>> 178
>> 179 config HARDENED_USERCOPY_PAGESPAN
>> 180 bool "Refuse to copy allocations that span multiple pages"
>> 181 depends on HARDENED_USERCOPY
>> 182 depends on EXPERT
>> 183 help
>> 184 When a multi-page allocation is done without __GFP_COMP,
>> 185 hardened usercopy will reject attempts to copy it. There are,
>> 186 however, several cases of this in the kernel that have not all
>> 187 been removed. This config is intended to be used only while
>> 188 trying to find such users.
>> 189
174 config FORTIFY_SOURCE 190 config FORTIFY_SOURCE
175 bool "Harden common str/mem functions 191 bool "Harden common str/mem functions against buffer overflows"
176 depends on ARCH_HAS_FORTIFY_SOURCE 192 depends on ARCH_HAS_FORTIFY_SOURCE
177 # https://github.com/llvm/llvm-project <<
178 depends on !CC_IS_CLANG || !X86_32 <<
179 help 193 help
180 Detect overflows of buffers in commo 194 Detect overflows of buffers in common string and memory functions
181 where the compiler can determine and 195 where the compiler can determine and validate the buffer sizes.
182 196
183 config STATIC_USERMODEHELPER 197 config STATIC_USERMODEHELPER
184 bool "Force all usermode helper calls 198 bool "Force all usermode helper calls through a single binary"
185 help 199 help
186 By default, the kernel can call many 200 By default, the kernel can call many different userspace
187 binary programs through the "usermod 201 binary programs through the "usermode helper" kernel
188 interface. Some of these binaries a 202 interface. Some of these binaries are statically defined
189 either in the kernel code itself, or 203 either in the kernel code itself, or as a kernel configuration
190 option. However, some of these are 204 option. However, some of these are dynamically created at
191 runtime, or can be modified after th 205 runtime, or can be modified after the kernel has started up.
192 To provide an additional layer of se 206 To provide an additional layer of security, route all of these
193 calls through a single executable th 207 calls through a single executable that can not have its name
194 changed. 208 changed.
195 209
196 Note, it is up to this single binary 210 Note, it is up to this single binary to then call the relevant
197 "real" usermode helper binary, based 211 "real" usermode helper binary, based on the first argument
198 passed to it. If desired, this prog 212 passed to it. If desired, this program can filter and pick
199 and choose what real programs are ca 213 and choose what real programs are called.
200 214
201 If you wish for all usermode helper 215 If you wish for all usermode helper programs are to be
202 disabled, choose this option and the 216 disabled, choose this option and then set
203 STATIC_USERMODEHELPER_PATH to an emp 217 STATIC_USERMODEHELPER_PATH to an empty string.
204 218
205 config STATIC_USERMODEHELPER_PATH 219 config STATIC_USERMODEHELPER_PATH
206 string "Path to the static usermode he 220 string "Path to the static usermode helper binary"
207 depends on STATIC_USERMODEHELPER 221 depends on STATIC_USERMODEHELPER
208 default "/sbin/usermode-helper" 222 default "/sbin/usermode-helper"
209 help 223 help
210 The binary called by the kernel when 224 The binary called by the kernel when any usermode helper
211 program is wish to be run. The "rea 225 program is wish to be run. The "real" application's name will
212 be in the first argument passed to t 226 be in the first argument passed to this program on the command
213 line. 227 line.
214 228
215 If you wish for all usermode helper 229 If you wish for all usermode helper programs to be disabled,
216 specify an empty string here (i.e. " 230 specify an empty string here (i.e. "").
217 231
218 source "security/selinux/Kconfig" 232 source "security/selinux/Kconfig"
219 source "security/smack/Kconfig" 233 source "security/smack/Kconfig"
220 source "security/tomoyo/Kconfig" 234 source "security/tomoyo/Kconfig"
221 source "security/apparmor/Kconfig" 235 source "security/apparmor/Kconfig"
222 source "security/loadpin/Kconfig" 236 source "security/loadpin/Kconfig"
223 source "security/yama/Kconfig" 237 source "security/yama/Kconfig"
224 source "security/safesetid/Kconfig" 238 source "security/safesetid/Kconfig"
225 source "security/lockdown/Kconfig" <<
226 source "security/landlock/Kconfig" <<
227 source "security/ipe/Kconfig" <<
228 239
229 source "security/integrity/Kconfig" 240 source "security/integrity/Kconfig"
230 241
231 choice 242 choice
232 prompt "First legacy 'major LSM' to be 243 prompt "First legacy 'major LSM' to be initialized"
233 default DEFAULT_SECURITY_SELINUX if SE 244 default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX
234 default DEFAULT_SECURITY_SMACK if SECU 245 default DEFAULT_SECURITY_SMACK if SECURITY_SMACK
235 default DEFAULT_SECURITY_TOMOYO if SEC 246 default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO
236 default DEFAULT_SECURITY_APPARMOR if S 247 default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR
237 default DEFAULT_SECURITY_DAC 248 default DEFAULT_SECURITY_DAC
238 249
239 help 250 help
240 This choice is there only for conver 251 This choice is there only for converting CONFIG_DEFAULT_SECURITY
241 in old kernel configs to CONFIG_LSM 252 in old kernel configs to CONFIG_LSM in new kernel configs. Don't
242 change this choice unless you are cr 253 change this choice unless you are creating a fresh kernel config,
243 for this choice will be ignored afte 254 for this choice will be ignored after CONFIG_LSM has been set.
244 255
245 Selects the legacy "major security m 256 Selects the legacy "major security module" that will be
246 initialized first. Overridden by non 257 initialized first. Overridden by non-default CONFIG_LSM.
247 258
248 config DEFAULT_SECURITY_SELINUX 259 config DEFAULT_SECURITY_SELINUX
249 bool "SELinux" if SECURITY_SEL 260 bool "SELinux" if SECURITY_SELINUX=y
250 261
251 config DEFAULT_SECURITY_SMACK 262 config DEFAULT_SECURITY_SMACK
252 bool "Simplified Mandatory Acc 263 bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y
253 264
254 config DEFAULT_SECURITY_TOMOYO 265 config DEFAULT_SECURITY_TOMOYO
255 bool "TOMOYO" if SECURITY_TOMO 266 bool "TOMOYO" if SECURITY_TOMOYO=y
256 267
257 config DEFAULT_SECURITY_APPARMOR 268 config DEFAULT_SECURITY_APPARMOR
258 bool "AppArmor" if SECURITY_AP 269 bool "AppArmor" if SECURITY_APPARMOR=y
259 270
260 config DEFAULT_SECURITY_DAC 271 config DEFAULT_SECURITY_DAC
261 bool "Unix Discretionary Acces 272 bool "Unix Discretionary Access Controls"
262 273
263 endchoice 274 endchoice
264 275
265 config LSM 276 config LSM
266 string "Ordered list of enabled LSMs" 277 string "Ordered list of enabled LSMs"
267 default "landlock,lockdown,yama,loadpi !! 278 default "yama,loadpin,safesetid,integrity,smack,selinux,tomoyo,apparmor" if DEFAULT_SECURITY_SMACK
268 default "landlock,lockdown,yama,loadpi !! 279 default "yama,loadpin,safesetid,integrity,apparmor,selinux,smack,tomoyo" if DEFAULT_SECURITY_APPARMOR
269 default "landlock,lockdown,yama,loadpi !! 280 default "yama,loadpin,safesetid,integrity,tomoyo" if DEFAULT_SECURITY_TOMOYO
270 default "landlock,lockdown,yama,loadpi !! 281 default "yama,loadpin,safesetid,integrity" if DEFAULT_SECURITY_DAC
271 default "landlock,lockdown,yama,loadpi !! 282 default "yama,loadpin,safesetid,integrity,selinux,smack,tomoyo,apparmor"
272 help 283 help
273 A comma-separated list of LSMs, in i 284 A comma-separated list of LSMs, in initialization order.
274 Any LSMs left off this list, except !! 285 Any LSMs left off this list will be ignored. This can be
275 LSM_ORDER_FIRST and LSM_ORDER_LAST, !! 286 controlled at boot with the "lsm=" parameter.
276 if selected in the kernel configurat <<
277 This can be controlled at boot with <<
278 287
279 If unsure, leave this as the default 288 If unsure, leave this as the default.
280 <<
281 source "security/Kconfig.hardening" <<
282 289
283 source "security/ccsecurity/Kconfig" 290 source "security/ccsecurity/Kconfig"
284 291
285 endmenu 292 endmenu
286 293
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