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