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ec8f24b7 | 1 | # SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | # |
3 | # Security configuration | |
4 | # | |
5 | ||
6 | menu "Security options" | |
7 | ||
8636a1f9 | 8 | source "security/keys/Kconfig" |
1da177e4 | 9 | |
eaf06b24 DR |
10 | config SECURITY_DMESG_RESTRICT |
11 | bool "Restrict unprivileged access to the kernel syslog" | |
12 | default n | |
13 | help | |
14 | This enforces restrictions on unprivileged users reading the kernel | |
15 | syslog via dmesg(8). | |
16 | ||
17 | If this option is not selected, no restrictions will be enforced | |
18 | unless the dmesg_restrict sysctl is explicitly set to (1). | |
19 | ||
20 | If you are unsure how to answer this question, answer N. | |
21 | ||
4e6246de BH |
22 | config SECURITY_PERF_EVENTS_RESTRICT |
23 | bool "Restrict unprivileged use of performance events" | |
24 | depends on PERF_EVENTS | |
25 | help | |
26 | If you say Y here, the kernel.perf_event_paranoid sysctl | |
27 | will be set to 3 by default, and no unprivileged use of the | |
28 | perf_event_open syscall will be permitted unless it is | |
29 | changed. | |
30 | ||
1da177e4 LT |
31 | config SECURITY |
32 | bool "Enable different security models" | |
2c40579b | 33 | depends on SYSFS |
2813893f | 34 | depends on MULTIUSER |
1da177e4 LT |
35 | help |
36 | This allows you to choose different security modules to be | |
37 | configured into your kernel. | |
38 | ||
39 | If this option is not selected, the default Linux security | |
40 | model will be used. | |
41 | ||
42 | If you are unsure how to answer this question, answer N. | |
43 | ||
dd0859dc JM |
44 | config SECURITY_WRITABLE_HOOKS |
45 | depends on SECURITY | |
46 | bool | |
47 | default n | |
48 | ||
da31894e EP |
49 | config SECURITYFS |
50 | bool "Enable the securityfs filesystem" | |
51 | help | |
52 | This will build the securityfs filesystem. It is currently used by | |
b102c11e | 53 | various security modules (AppArmor, IMA, SafeSetID, TOMOYO, TPM). |
da31894e EP |
54 | |
55 | If you are unsure how to answer this question, answer N. | |
56 | ||
1da177e4 LT |
57 | config SECURITY_NETWORK |
58 | bool "Socket and Networking Security Hooks" | |
59 | depends on SECURITY | |
60 | help | |
61 | This enables the socket and networking security hooks. | |
62 | If enabled, a security module can use these hooks to | |
63 | implement socket and networking access controls. | |
64 | If you are unsure how to answer this question, answer N. | |
df71837d | 65 | |
385ce0ea DH |
66 | config PAGE_TABLE_ISOLATION |
67 | bool "Remove the kernel mapping in user mode" | |
87faa0d9 | 68 | default y |
61a6bd83 | 69 | depends on (X86_64 || X86_PAE) && !UML |
385ce0ea DH |
70 | help |
71 | This feature reduces the number of hardware side channels by | |
72 | ensuring that the majority of kernel addresses are not mapped | |
73 | into userspace. | |
74 | ||
cb1aaebe | 75 | See Documentation/x86/pti.rst for more details. |
385ce0ea | 76 | |
d291f1a6 DJ |
77 | config SECURITY_INFINIBAND |
78 | bool "Infiniband Security Hooks" | |
79 | depends on SECURITY && INFINIBAND | |
80 | help | |
81 | This enables the Infiniband security hooks. | |
82 | If enabled, a security module can use these hooks to | |
83 | implement Infiniband access controls. | |
84 | If you are unsure how to answer this question, answer N. | |
85 | ||
df71837d TJ |
86 | config SECURITY_NETWORK_XFRM |
87 | bool "XFRM (IPSec) Networking Security Hooks" | |
88 | depends on XFRM && SECURITY_NETWORK | |
89 | help | |
90 | This enables the XFRM (IPSec) networking security hooks. | |
91 | If enabled, a security module can use these hooks to | |
92 | implement per-packet access controls based on labels | |
93 | derived from IPSec policy. Non-IPSec communications are | |
94 | designated as unlabelled, and only sockets authorized | |
95 | to communicate unlabelled data can send without using | |
96 | IPSec. | |
97 | If you are unsure how to answer this question, answer N. | |
1da177e4 | 98 | |
be6d3e56 KT |
99 | config SECURITY_PATH |
100 | bool "Security hooks for pathname based access control" | |
101 | depends on SECURITY | |
102 | help | |
103 | This enables the security hooks for pathname based access control. | |
104 | If enabled, a security module can use these hooks to | |
105 | implement pathname based access controls. | |
106 | If you are unsure how to answer this question, answer N. | |
107 | ||
31625340 JC |
108 | config INTEL_TXT |
109 | bool "Enable Intel(R) Trusted Execution Technology (Intel(R) TXT)" | |
69575d38 | 110 | depends on HAVE_INTEL_TXT |
31625340 JC |
111 | help |
112 | This option enables support for booting the kernel with the | |
113 | Trusted Boot (tboot) module. This will utilize | |
114 | Intel(R) Trusted Execution Technology to perform a measured launch | |
115 | of the kernel. If the system does not support Intel(R) TXT, this | |
116 | will have no effect. | |
117 | ||
3c556e41 | 118 | Intel TXT will provide higher assurance of system configuration and |
31625340 JC |
119 | initial state as well as data reset protection. This is used to |
120 | create a robust initial kernel measurement and verification, which | |
121 | helps to ensure that kernel security mechanisms are functioning | |
122 | correctly. This level of protection requires a root of trust outside | |
123 | of the kernel itself. | |
124 | ||
125 | Intel TXT also helps solve real end user concerns about having | |
126 | confidence that their hardware is running the VMM or kernel that | |
3c556e41 | 127 | it was configured with, especially since they may be responsible for |
31625340 JC |
128 | providing such assurances to VMs and services running on it. |
129 | ||
130 | See <http://www.intel.com/technology/security/> for more information | |
131 | about Intel(R) TXT. | |
132 | See <http://tboot.sourceforge.net> for more information about tboot. | |
e8d776f2 | 133 | See Documentation/x86/intel_txt.rst for a description of how to enable |
31625340 JC |
134 | Intel TXT support in a kernel boot. |
135 | ||
136 | If you are unsure as to whether this is required, answer N. | |
137 | ||
788084ab | 138 | config LSM_MMAP_MIN_ADDR |
024e6cb4 | 139 | int "Low address space for LSM to protect from user allocation" |
788084ab | 140 | depends on SECURITY && SECURITY_SELINUX |
530b099d | 141 | default 32768 if ARM || (ARM64 && COMPAT) |
a58578e4 | 142 | default 65536 |
788084ab EP |
143 | help |
144 | This is the portion of low virtual memory which should be protected | |
145 | from userspace allocation. Keeping a user from writing to low pages | |
146 | can help reduce the impact of kernel NULL pointer bugs. | |
147 | ||
148 | For most ia64, ppc64 and x86 users with lots of address space | |
149 | a value of 65536 is reasonable and should cause no problems. | |
150 | On arm and other archs it should not be higher than 32768. | |
151 | Programs which use vm86 functionality or have some need to map | |
152 | this low address space will need the permission specific to the | |
153 | systems running LSM. | |
154 | ||
f5509cc1 KC |
155 | config HAVE_HARDENED_USERCOPY_ALLOCATOR |
156 | bool | |
157 | help | |
158 | The heap allocator implements __check_heap_object() for | |
159 | validating memory ranges against heap object sizes in | |
160 | support of CONFIG_HARDENED_USERCOPY. | |
161 | ||
f5509cc1 KC |
162 | config HARDENED_USERCOPY |
163 | bool "Harden memory copies between kernel and userspace" | |
6040e576 | 164 | depends on HAVE_HARDENED_USERCOPY_ALLOCATOR |
22ec1a2a | 165 | imply STRICT_DEVMEM |
f5509cc1 KC |
166 | help |
167 | This option checks for obviously wrong memory regions when | |
168 | copying memory to/from the kernel (via copy_to_user() and | |
169 | copy_from_user() functions) by rejecting memory ranges that | |
170 | are larger than the specified heap object, span multiple | |
99c55fb1 | 171 | separately allocated pages, are not on the process stack, |
f5509cc1 KC |
172 | or are part of the kernel text. This kills entire classes |
173 | of heap overflow exploits and similar kernel memory exposures. | |
174 | ||
2d891fbc KC |
175 | config HARDENED_USERCOPY_FALLBACK |
176 | bool "Allow usercopy whitelist violations to fallback to object size" | |
177 | depends on HARDENED_USERCOPY | |
178 | default y | |
179 | help | |
180 | This is a temporary option that allows missing usercopy whitelists | |
181 | to be discovered via a WARN() to the kernel log, instead of | |
182 | rejecting the copy, falling back to non-whitelisted hardened | |
183 | usercopy that checks the slab allocation size instead of the | |
184 | whitelist size. This option will be removed once it seems like | |
185 | all missing usercopy whitelists have been identified and fixed. | |
186 | Booting with "slab_common.usercopy_fallback=Y/N" can change | |
187 | this setting. | |
188 | ||
8e1f74ea KC |
189 | config HARDENED_USERCOPY_PAGESPAN |
190 | bool "Refuse to copy allocations that span multiple pages" | |
191 | depends on HARDENED_USERCOPY | |
80a77045 | 192 | depends on EXPERT |
8e1f74ea KC |
193 | help |
194 | When a multi-page allocation is done without __GFP_COMP, | |
195 | hardened usercopy will reject attempts to copy it. There are, | |
196 | however, several cases of this in the kernel that have not all | |
197 | been removed. This config is intended to be used only while | |
198 | trying to find such users. | |
199 | ||
6974f0c4 DM |
200 | config FORTIFY_SOURCE |
201 | bool "Harden common str/mem functions against buffer overflows" | |
202 | depends on ARCH_HAS_FORTIFY_SOURCE | |
203 | help | |
204 | Detect overflows of buffers in common string and memory functions | |
205 | where the compiler can determine and validate the buffer sizes. | |
206 | ||
64e90a8a GKH |
207 | config STATIC_USERMODEHELPER |
208 | bool "Force all usermode helper calls through a single binary" | |
209 | help | |
210 | By default, the kernel can call many different userspace | |
211 | binary programs through the "usermode helper" kernel | |
212 | interface. Some of these binaries are statically defined | |
213 | either in the kernel code itself, or as a kernel configuration | |
214 | option. However, some of these are dynamically created at | |
215 | runtime, or can be modified after the kernel has started up. | |
216 | To provide an additional layer of security, route all of these | |
217 | calls through a single executable that can not have its name | |
218 | changed. | |
219 | ||
220 | Note, it is up to this single binary to then call the relevant | |
221 | "real" usermode helper binary, based on the first argument | |
222 | passed to it. If desired, this program can filter and pick | |
223 | and choose what real programs are called. | |
224 | ||
225 | If you wish for all usermode helper programs are to be | |
226 | disabled, choose this option and then set | |
227 | STATIC_USERMODEHELPER_PATH to an empty string. | |
228 | ||
229 | config STATIC_USERMODEHELPER_PATH | |
230 | string "Path to the static usermode helper binary" | |
231 | depends on STATIC_USERMODEHELPER | |
232 | default "/sbin/usermode-helper" | |
233 | help | |
234 | The binary called by the kernel when any usermode helper | |
235 | program is wish to be run. The "real" application's name will | |
236 | be in the first argument passed to this program on the command | |
237 | line. | |
238 | ||
239 | If you wish for all usermode helper programs to be disabled, | |
240 | specify an empty string here (i.e. ""). | |
241 | ||
8636a1f9 MY |
242 | source "security/selinux/Kconfig" |
243 | source "security/smack/Kconfig" | |
244 | source "security/tomoyo/Kconfig" | |
245 | source "security/apparmor/Kconfig" | |
246 | source "security/loadpin/Kconfig" | |
247 | source "security/yama/Kconfig" | |
aeca4e2c | 248 | source "security/safesetid/Kconfig" |
000d388e | 249 | source "security/lockdown/Kconfig" |
1da177e4 | 250 | |
8636a1f9 | 251 | source "security/integrity/Kconfig" |
3323eec9 | 252 | |
2623c4fb KC |
253 | choice |
254 | prompt "First legacy 'major LSM' to be initialized" | |
255 | default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX | |
256 | default DEFAULT_SECURITY_SMACK if SECURITY_SMACK | |
257 | default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO | |
258 | default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR | |
259 | default DEFAULT_SECURITY_DAC | |
260 | ||
261 | help | |
262 | This choice is there only for converting CONFIG_DEFAULT_SECURITY | |
263 | in old kernel configs to CONFIG_LSM in new kernel configs. Don't | |
264 | change this choice unless you are creating a fresh kernel config, | |
265 | for this choice will be ignored after CONFIG_LSM has been set. | |
266 | ||
267 | Selects the legacy "major security module" that will be | |
268 | initialized first. Overridden by non-default CONFIG_LSM. | |
269 | ||
270 | config DEFAULT_SECURITY_SELINUX | |
271 | bool "SELinux" if SECURITY_SELINUX=y | |
272 | ||
273 | config DEFAULT_SECURITY_SMACK | |
274 | bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y | |
275 | ||
276 | config DEFAULT_SECURITY_TOMOYO | |
277 | bool "TOMOYO" if SECURITY_TOMOYO=y | |
278 | ||
279 | config DEFAULT_SECURITY_APPARMOR | |
280 | bool "AppArmor" if SECURITY_APPARMOR=y | |
281 | ||
282 | config DEFAULT_SECURITY_DAC | |
283 | bool "Unix Discretionary Access Controls" | |
284 | ||
285 | endchoice | |
286 | ||
13e735c0 KC |
287 | config LSM |
288 | string "Ordered list of enabled LSMs" | |
000d388e MG |
289 | default "lockdown,yama,loadpin,safesetid,integrity,smack,selinux,tomoyo,apparmor" if DEFAULT_SECURITY_SMACK |
290 | default "lockdown,yama,loadpin,safesetid,integrity,apparmor,selinux,smack,tomoyo" if DEFAULT_SECURITY_APPARMOR | |
291 | default "lockdown,yama,loadpin,safesetid,integrity,tomoyo" if DEFAULT_SECURITY_TOMOYO | |
292 | default "lockdown,yama,loadpin,safesetid,integrity" if DEFAULT_SECURITY_DAC | |
293 | default "lockdown,yama,loadpin,safesetid,integrity,selinux,smack,tomoyo,apparmor" | |
13e735c0 KC |
294 | help |
295 | A comma-separated list of LSMs, in initialization order. | |
79f7865d KC |
296 | Any LSMs left off this list will be ignored. This can be |
297 | controlled at boot with the "lsm=" parameter. | |
13e735c0 KC |
298 | |
299 | If unsure, leave this as the default. | |
300 | ||
9f671e58 KC |
301 | source "security/Kconfig.hardening" |
302 | ||
1da177e4 LT |
303 | endmenu |
304 |