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