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