1 # SPDX-License-Identifier: GPL-2.0-only 1 # SPDX-License-Identifier: GPL-2.0-only
2 # 2 #
3 # Security configuration 3 # Security configuration
4 # 4 #
5 5
6 menu "Security options" 6 menu "Security options"
7 7
8 source "security/keys/Kconfig" 8 source "security/keys/Kconfig"
9 9
10 config SECURITY_DMESG_RESTRICT 10 config SECURITY_DMESG_RESTRICT
11 bool "Restrict unprivileged access to 11 bool "Restrict unprivileged access to the kernel syslog"
12 default n 12 default n
13 help 13 help
14 This enforces restrictions on unpriv 14 This enforces restrictions on unprivileged users reading the kernel
15 syslog via dmesg(8). 15 syslog via dmesg(8).
16 16
17 If this option is not selected, no r 17 If this option is not selected, no restrictions will be enforced
18 unless the dmesg_restrict sysctl is 18 unless the dmesg_restrict sysctl is explicitly set to (1).
19 19
20 If you are unsure how to answer this 20 If you are unsure how to answer this question, answer N.
21 21
22 choice 22 choice
23 prompt "Allow /proc/pid/mem access ove 23 prompt "Allow /proc/pid/mem access override"
24 default PROC_MEM_ALWAYS_FORCE 24 default PROC_MEM_ALWAYS_FORCE
25 help 25 help
26 Traditionally /proc/pid/mem allows u 26 Traditionally /proc/pid/mem allows users to override memory
27 permissions for users like ptrace, a 27 permissions for users like ptrace, assuming they have ptrace
28 capability. 28 capability.
29 29
30 This allows people to limit that - e 30 This allows people to limit that - either never override, or
31 require actual active ptrace attachm 31 require actual active ptrace attachment.
32 32
33 Defaults to the traditional behavior 33 Defaults to the traditional behavior (for now)
34 34
35 config PROC_MEM_ALWAYS_FORCE 35 config PROC_MEM_ALWAYS_FORCE
36 bool "Traditional /proc/pid/mem behavi 36 bool "Traditional /proc/pid/mem behavior"
37 help 37 help
38 This allows /proc/pid/mem accesses t 38 This allows /proc/pid/mem accesses to override memory mapping
39 permissions if you have ptrace acces 39 permissions if you have ptrace access rights.
40 40
41 config PROC_MEM_FORCE_PTRACE 41 config PROC_MEM_FORCE_PTRACE
42 bool "Require active ptrace() use for 42 bool "Require active ptrace() use for access override"
43 help 43 help
44 This allows /proc/pid/mem accesses t 44 This allows /proc/pid/mem accesses to override memory mapping
45 permissions for active ptracers like 45 permissions for active ptracers like gdb.
46 46
47 config PROC_MEM_NO_FORCE 47 config PROC_MEM_NO_FORCE
48 bool "Never" 48 bool "Never"
49 help 49 help
50 Never override memory mapping permis 50 Never override memory mapping permissions
51 51
52 endchoice 52 endchoice
53 53
54 config SECURITY 54 config SECURITY
55 bool "Enable different security models 55 bool "Enable different security models"
56 depends on SYSFS 56 depends on SYSFS
57 depends on MULTIUSER 57 depends on MULTIUSER
58 help 58 help
59 This allows you to choose different 59 This allows you to choose different security modules to be
60 configured into your kernel. 60 configured into your kernel.
61 61
62 If this option is not selected, the 62 If this option is not selected, the default Linux security
63 model will be used. 63 model will be used.
64 64
65 If you are unsure how to answer this 65 If you are unsure how to answer this question, answer N.
66 66
67 config SECURITYFS 67 config SECURITYFS
68 bool "Enable the securityfs filesystem 68 bool "Enable the securityfs filesystem"
69 help 69 help
70 This will build the securityfs files 70 This will build the securityfs filesystem. It is currently used by
71 various security modules (AppArmor, 71 various security modules (AppArmor, IMA, SafeSetID, TOMOYO, TPM).
72 72
73 If you are unsure how to answer this 73 If you are unsure how to answer this question, answer N.
74 74
75 config SECURITY_NETWORK 75 config SECURITY_NETWORK
76 bool "Socket and Networking Security H 76 bool "Socket and Networking Security Hooks"
77 depends on SECURITY 77 depends on SECURITY
78 help 78 help
79 This enables the socket and networki 79 This enables the socket and networking security hooks.
80 If enabled, a security module can us 80 If enabled, a security module can use these hooks to
81 implement socket and networking acce 81 implement socket and networking access controls.
82 If you are unsure how to answer this 82 If you are unsure how to answer this question, answer N.
83 83
84 config SECURITY_INFINIBAND 84 config SECURITY_INFINIBAND
85 bool "Infiniband Security Hooks" 85 bool "Infiniband Security Hooks"
86 depends on SECURITY && INFINIBAND 86 depends on SECURITY && INFINIBAND
87 help 87 help
88 This enables the Infiniband security 88 This enables the Infiniband security hooks.
89 If enabled, a security module can us 89 If enabled, a security module can use these hooks to
90 implement Infiniband access controls 90 implement Infiniband access controls.
91 If you are unsure how to answer this 91 If you are unsure how to answer this question, answer N.
92 92
93 config SECURITY_NETWORK_XFRM 93 config SECURITY_NETWORK_XFRM
94 bool "XFRM (IPSec) Networking Security 94 bool "XFRM (IPSec) Networking Security Hooks"
95 depends on XFRM && SECURITY_NETWORK 95 depends on XFRM && SECURITY_NETWORK
96 help 96 help
97 This enables the XFRM (IPSec) networ 97 This enables the XFRM (IPSec) networking security hooks.
98 If enabled, a security module can us 98 If enabled, a security module can use these hooks to
99 implement per-packet access controls 99 implement per-packet access controls based on labels
100 derived from IPSec policy. Non-IPSe 100 derived from IPSec policy. Non-IPSec communications are
101 designated as unlabelled, and only s 101 designated as unlabelled, and only sockets authorized
102 to communicate unlabelled data can s 102 to communicate unlabelled data can send without using
103 IPSec. 103 IPSec.
104 If you are unsure how to answer this 104 If you are unsure how to answer this question, answer N.
105 105
106 config SECURITY_PATH 106 config SECURITY_PATH
107 bool "Security hooks for pathname base 107 bool "Security hooks for pathname based access control"
108 depends on SECURITY 108 depends on SECURITY
109 help 109 help
110 This enables the security hooks for 110 This enables the security hooks for pathname based access control.
111 If enabled, a security module can us 111 If enabled, a security module can use these hooks to
112 implement pathname based access cont 112 implement pathname based access controls.
113 If you are unsure how to answer this 113 If you are unsure how to answer this question, answer N.
114 114
115 config INTEL_TXT 115 config INTEL_TXT
116 bool "Enable Intel(R) Trusted Executio 116 bool "Enable Intel(R) Trusted Execution Technology (Intel(R) TXT)"
117 depends on HAVE_INTEL_TXT 117 depends on HAVE_INTEL_TXT
118 help 118 help
119 This option enables support for boot 119 This option enables support for booting the kernel with the
120 Trusted Boot (tboot) module. This wi 120 Trusted Boot (tboot) module. This will utilize
121 Intel(R) Trusted Execution Technolog 121 Intel(R) Trusted Execution Technology to perform a measured launch
122 of the kernel. If the system does no 122 of the kernel. If the system does not support Intel(R) TXT, this
123 will have no effect. 123 will have no effect.
124 124
125 Intel TXT will provide higher assura 125 Intel TXT will provide higher assurance of system configuration and
126 initial state as well as data reset 126 initial state as well as data reset protection. This is used to
127 create a robust initial kernel measu 127 create a robust initial kernel measurement and verification, which
128 helps to ensure that kernel security 128 helps to ensure that kernel security mechanisms are functioning
129 correctly. This level of protection 129 correctly. This level of protection requires a root of trust outside
130 of the kernel itself. 130 of the kernel itself.
131 131
132 Intel TXT also helps solve real end 132 Intel TXT also helps solve real end user concerns about having
133 confidence that their hardware is ru 133 confidence that their hardware is running the VMM or kernel that
134 it was configured with, especially s 134 it was configured with, especially since they may be responsible for
135 providing such assurances to VMs and 135 providing such assurances to VMs and services running on it.
136 136
137 See <https://www.intel.com/technolog 137 See <https://www.intel.com/technology/security/> for more information
138 about Intel(R) TXT. 138 about Intel(R) TXT.
139 See <http://tboot.sourceforge.net> f 139 See <http://tboot.sourceforge.net> for more information about tboot.
140 See Documentation/arch/x86/intel_txt 140 See Documentation/arch/x86/intel_txt.rst for a description of how to enable
141 Intel TXT support in a kernel boot. 141 Intel TXT support in a kernel boot.
142 142
143 If you are unsure as to whether this 143 If you are unsure as to whether this is required, answer N.
144 144
145 config LSM_MMAP_MIN_ADDR 145 config LSM_MMAP_MIN_ADDR
146 int "Low address space for LSM to prot 146 int "Low address space for LSM to protect from user allocation"
147 depends on SECURITY && SECURITY_SELINU 147 depends on SECURITY && SECURITY_SELINUX
148 default 32768 if ARM || (ARM64 && COMP 148 default 32768 if ARM || (ARM64 && COMPAT)
149 default 65536 149 default 65536
150 help 150 help
151 This is the portion of low virtual m 151 This is the portion of low virtual memory which should be protected
152 from userspace allocation. Keeping 152 from userspace allocation. Keeping a user from writing to low pages
153 can help reduce the impact of kernel 153 can help reduce the impact of kernel NULL pointer bugs.
154 154
155 For most ia64, ppc64 and x86 users w 155 For most ia64, ppc64 and x86 users with lots of address space
156 a value of 65536 is reasonable and s 156 a value of 65536 is reasonable and should cause no problems.
157 On arm and other archs it should not 157 On arm and other archs it should not be higher than 32768.
158 Programs which use vm86 functionalit 158 Programs which use vm86 functionality or have some need to map
159 this low address space will need the 159 this low address space will need the permission specific to the
160 systems running LSM. 160 systems running LSM.
161 161
162 config HARDENED_USERCOPY 162 config HARDENED_USERCOPY
163 bool "Harden memory copies between ker 163 bool "Harden memory copies between kernel and userspace"
164 imply STRICT_DEVMEM 164 imply STRICT_DEVMEM
165 help 165 help
166 This option checks for obviously wro 166 This option checks for obviously wrong memory regions when
167 copying memory to/from the kernel (v 167 copying memory to/from the kernel (via copy_to_user() and
168 copy_from_user() functions) by rejec 168 copy_from_user() functions) by rejecting memory ranges that
169 are larger than the specified heap o 169 are larger than the specified heap object, span multiple
170 separately allocated pages, are not 170 separately allocated pages, are not on the process stack,
171 or are part of the kernel text. This 171 or are part of the kernel text. This prevents entire classes
172 of heap overflow exploits and simila 172 of heap overflow exploits and similar kernel memory exposures.
173 173
174 config FORTIFY_SOURCE 174 config FORTIFY_SOURCE
175 bool "Harden common str/mem functions 175 bool "Harden common str/mem functions against buffer overflows"
176 depends on ARCH_HAS_FORTIFY_SOURCE 176 depends on ARCH_HAS_FORTIFY_SOURCE
>> 177 # https://bugs.llvm.org/show_bug.cgi?id=41459
>> 178 depends on !CC_IS_CLANG || CLANG_VERSION >= 120001
177 # https://github.com/llvm/llvm-project 179 # https://github.com/llvm/llvm-project/issues/53645
178 depends on !CC_IS_CLANG || !X86_32 180 depends on !CC_IS_CLANG || !X86_32
179 help 181 help
180 Detect overflows of buffers in commo 182 Detect overflows of buffers in common string and memory functions
181 where the compiler can determine and 183 where the compiler can determine and validate the buffer sizes.
182 184
183 config STATIC_USERMODEHELPER 185 config STATIC_USERMODEHELPER
184 bool "Force all usermode helper calls 186 bool "Force all usermode helper calls through a single binary"
185 help 187 help
186 By default, the kernel can call many 188 By default, the kernel can call many different userspace
187 binary programs through the "usermod 189 binary programs through the "usermode helper" kernel
188 interface. Some of these binaries a 190 interface. Some of these binaries are statically defined
189 either in the kernel code itself, or 191 either in the kernel code itself, or as a kernel configuration
190 option. However, some of these are 192 option. However, some of these are dynamically created at
191 runtime, or can be modified after th 193 runtime, or can be modified after the kernel has started up.
192 To provide an additional layer of se 194 To provide an additional layer of security, route all of these
193 calls through a single executable th 195 calls through a single executable that can not have its name
194 changed. 196 changed.
195 197
196 Note, it is up to this single binary 198 Note, it is up to this single binary to then call the relevant
197 "real" usermode helper binary, based 199 "real" usermode helper binary, based on the first argument
198 passed to it. If desired, this prog 200 passed to it. If desired, this program can filter and pick
199 and choose what real programs are ca 201 and choose what real programs are called.
200 202
201 If you wish for all usermode helper 203 If you wish for all usermode helper programs are to be
202 disabled, choose this option and the 204 disabled, choose this option and then set
203 STATIC_USERMODEHELPER_PATH to an emp 205 STATIC_USERMODEHELPER_PATH to an empty string.
204 206
205 config STATIC_USERMODEHELPER_PATH 207 config STATIC_USERMODEHELPER_PATH
206 string "Path to the static usermode he 208 string "Path to the static usermode helper binary"
207 depends on STATIC_USERMODEHELPER 209 depends on STATIC_USERMODEHELPER
208 default "/sbin/usermode-helper" 210 default "/sbin/usermode-helper"
209 help 211 help
210 The binary called by the kernel when 212 The binary called by the kernel when any usermode helper
211 program is wish to be run. The "rea 213 program is wish to be run. The "real" application's name will
212 be in the first argument passed to t 214 be in the first argument passed to this program on the command
213 line. 215 line.
214 216
215 If you wish for all usermode helper 217 If you wish for all usermode helper programs to be disabled,
216 specify an empty string here (i.e. " 218 specify an empty string here (i.e. "").
217 219
218 source "security/selinux/Kconfig" 220 source "security/selinux/Kconfig"
219 source "security/smack/Kconfig" 221 source "security/smack/Kconfig"
220 source "security/tomoyo/Kconfig" 222 source "security/tomoyo/Kconfig"
221 source "security/apparmor/Kconfig" 223 source "security/apparmor/Kconfig"
222 source "security/loadpin/Kconfig" 224 source "security/loadpin/Kconfig"
223 source "security/yama/Kconfig" 225 source "security/yama/Kconfig"
224 source "security/safesetid/Kconfig" 226 source "security/safesetid/Kconfig"
225 source "security/lockdown/Kconfig" 227 source "security/lockdown/Kconfig"
226 source "security/landlock/Kconfig" 228 source "security/landlock/Kconfig"
227 source "security/ipe/Kconfig" <<
228 229
229 source "security/integrity/Kconfig" 230 source "security/integrity/Kconfig"
230 231
231 choice 232 choice
232 prompt "First legacy 'major LSM' to be 233 prompt "First legacy 'major LSM' to be initialized"
233 default DEFAULT_SECURITY_SELINUX if SE 234 default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX
234 default DEFAULT_SECURITY_SMACK if SECU 235 default DEFAULT_SECURITY_SMACK if SECURITY_SMACK
235 default DEFAULT_SECURITY_TOMOYO if SEC 236 default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO
236 default DEFAULT_SECURITY_APPARMOR if S 237 default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR
237 default DEFAULT_SECURITY_DAC 238 default DEFAULT_SECURITY_DAC
238 239
239 help 240 help
240 This choice is there only for conver 241 This choice is there only for converting CONFIG_DEFAULT_SECURITY
241 in old kernel configs to CONFIG_LSM 242 in old kernel configs to CONFIG_LSM in new kernel configs. Don't
242 change this choice unless you are cr 243 change this choice unless you are creating a fresh kernel config,
243 for this choice will be ignored afte 244 for this choice will be ignored after CONFIG_LSM has been set.
244 245
245 Selects the legacy "major security m 246 Selects the legacy "major security module" that will be
246 initialized first. Overridden by non 247 initialized first. Overridden by non-default CONFIG_LSM.
247 248
248 config DEFAULT_SECURITY_SELINUX 249 config DEFAULT_SECURITY_SELINUX
249 bool "SELinux" if SECURITY_SEL 250 bool "SELinux" if SECURITY_SELINUX=y
250 251
251 config DEFAULT_SECURITY_SMACK 252 config DEFAULT_SECURITY_SMACK
252 bool "Simplified Mandatory Acc 253 bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y
253 254
254 config DEFAULT_SECURITY_TOMOYO 255 config DEFAULT_SECURITY_TOMOYO
255 bool "TOMOYO" if SECURITY_TOMO 256 bool "TOMOYO" if SECURITY_TOMOYO=y
256 257
257 config DEFAULT_SECURITY_APPARMOR 258 config DEFAULT_SECURITY_APPARMOR
258 bool "AppArmor" if SECURITY_AP 259 bool "AppArmor" if SECURITY_APPARMOR=y
259 260
260 config DEFAULT_SECURITY_DAC 261 config DEFAULT_SECURITY_DAC
261 bool "Unix Discretionary Acces 262 bool "Unix Discretionary Access Controls"
262 263
263 endchoice 264 endchoice
264 265
265 config LSM 266 config LSM
266 string "Ordered list of enabled LSMs" 267 string "Ordered list of enabled LSMs"
267 default "landlock,lockdown,yama,loadpi !! 268 default "landlock,lockdown,yama,loadpin,safesetid,smack,selinux,tomoyo,apparmor,bpf" if DEFAULT_SECURITY_SMACK
268 default "landlock,lockdown,yama,loadpi !! 269 default "landlock,lockdown,yama,loadpin,safesetid,apparmor,selinux,smack,tomoyo,bpf" if DEFAULT_SECURITY_APPARMOR
269 default "landlock,lockdown,yama,loadpi !! 270 default "landlock,lockdown,yama,loadpin,safesetid,tomoyo,bpf" if DEFAULT_SECURITY_TOMOYO
270 default "landlock,lockdown,yama,loadpi !! 271 default "landlock,lockdown,yama,loadpin,safesetid,bpf" if DEFAULT_SECURITY_DAC
271 default "landlock,lockdown,yama,loadpi !! 272 default "landlock,lockdown,yama,loadpin,safesetid,selinux,smack,tomoyo,apparmor,bpf"
272 help 273 help
273 A comma-separated list of LSMs, in i 274 A comma-separated list of LSMs, in initialization order.
274 Any LSMs left off this list, except 275 Any LSMs left off this list, except for those with order
275 LSM_ORDER_FIRST and LSM_ORDER_LAST, 276 LSM_ORDER_FIRST and LSM_ORDER_LAST, which are always enabled
276 if selected in the kernel configurat 277 if selected in the kernel configuration, will be ignored.
277 This can be controlled at boot with 278 This can be controlled at boot with the "lsm=" parameter.
278 279
279 If unsure, leave this as the default 280 If unsure, leave this as the default.
280 281
281 source "security/Kconfig.hardening" 282 source "security/Kconfig.hardening"
282 283
283 source "security/ccsecurity/Kconfig" 284 source "security/ccsecurity/Kconfig"
284 285
285 endmenu 286 endmenu
286 287
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