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1da177e4 LT |
1 | # |
2 | # Security configuration | |
3 | # | |
4 | ||
5 | menu "Security options" | |
6 | ||
f0894940 | 7 | source security/keys/Kconfig |
1da177e4 | 8 | |
eaf06b24 DR |
9 | config SECURITY_DMESG_RESTRICT |
10 | bool "Restrict unprivileged access to the kernel syslog" | |
11 | default n | |
12 | help | |
13 | This enforces restrictions on unprivileged users reading the kernel | |
14 | syslog via dmesg(8). | |
15 | ||
16 | If this option is not selected, no restrictions will be enforced | |
17 | unless the dmesg_restrict sysctl is explicitly set to (1). | |
18 | ||
19 | If you are unsure how to answer this question, answer N. | |
20 | ||
cc58fdf5 BH |
21 | config SECURITY_PERF_EVENTS_RESTRICT |
22 | bool "Restrict unprivileged use of performance events" | |
23 | depends on PERF_EVENTS | |
24 | help | |
25 | If you say Y here, the kernel.perf_event_paranoid sysctl | |
26 | will be set to 3 by default, and no unprivileged use of the | |
27 | perf_event_open syscall will be permitted unless it is | |
28 | changed. | |
29 | ||
1da177e4 LT |
30 | config SECURITY |
31 | bool "Enable different security models" | |
2c40579b | 32 | depends on SYSFS |
2813893f | 33 | depends on MULTIUSER |
1da177e4 LT |
34 | help |
35 | This allows you to choose different security modules to be | |
36 | configured into your kernel. | |
37 | ||
38 | If this option is not selected, the default Linux security | |
39 | model will be used. | |
40 | ||
41 | If you are unsure how to answer this question, answer N. | |
42 | ||
dd0859dc JM |
43 | config SECURITY_WRITABLE_HOOKS |
44 | depends on SECURITY | |
45 | bool | |
46 | default n | |
47 | ||
a3c3cde2 CS |
48 | config SECURITY_STACKING |
49 | bool "Security module stacking" | |
50 | depends on SECURITY | |
51 | help | |
52 | Allows multiple major security modules to be stacked. | |
53 | Modules are invoked in the order registered with a | |
54 | "bail on fail" policy, in which the infrastructure | |
55 | will stop processing once a denial is detected. Not | |
56 | all modules can be stacked. SELinux and Smack are | |
57 | known to be incompatible. User space components may | |
58 | have trouble identifying the security module providing | |
59 | data in some cases. | |
60 | ||
61 | If you select this option you will have to select which | |
62 | of the stackable modules you wish to be active. The | |
63 | "Default security module" will be ignored. The boot line | |
64 | "security=" option can be used to specify that one of | |
65 | the modules identifed for stacking should be used instead | |
66 | of the entire stack. | |
67 | ||
68 | If you are unsure how to answer this question, answer N. | |
69 | ||
98738d70 CS |
70 | config SECURITY_LSM_DEBUG |
71 | bool "Enable debugging of the LSM infrastructure" | |
72 | depends on SECURITY | |
73 | help | |
74 | This allows you to choose debug messages related to | |
75 | security modules configured into your kernel. These | |
76 | messages may be helpful in determining how a security | |
77 | module is using security blobs. | |
78 | ||
79 | If you are unsure how to answer this question, answer N. | |
80 | ||
da31894e EP |
81 | config SECURITYFS |
82 | bool "Enable the securityfs filesystem" | |
83 | help | |
84 | This will build the securityfs filesystem. It is currently used by | |
3323eec9 MZ |
85 | the TPM bios character driver and IMA, an integrity provider. It is |
86 | not used by SELinux or SMACK. | |
da31894e EP |
87 | |
88 | If you are unsure how to answer this question, answer N. | |
89 | ||
1da177e4 LT |
90 | config SECURITY_NETWORK |
91 | bool "Socket and Networking Security Hooks" | |
92 | depends on SECURITY | |
93 | help | |
94 | This enables the socket and networking security hooks. | |
95 | If enabled, a security module can use these hooks to | |
96 | implement socket and networking access controls. | |
97 | If you are unsure how to answer this question, answer N. | |
df71837d | 98 | |
ce12963b DH |
99 | config PAGE_TABLE_ISOLATION |
100 | bool "Remove the kernel mapping in user mode" | |
436cdbfe | 101 | default y |
ce12963b DH |
102 | depends on X86_64 && !UML |
103 | help | |
104 | This feature reduces the number of hardware side channels by | |
105 | ensuring that the majority of kernel addresses are not mapped | |
106 | into userspace. | |
107 | ||
748ab6f5 | 108 | See Documentation/x86/pti.txt for more details. |
ce12963b | 109 | |
d291f1a6 DJ |
110 | config SECURITY_INFINIBAND |
111 | bool "Infiniband Security Hooks" | |
112 | depends on SECURITY && INFINIBAND | |
113 | help | |
114 | This enables the Infiniband security hooks. | |
115 | If enabled, a security module can use these hooks to | |
116 | implement Infiniband access controls. | |
117 | If you are unsure how to answer this question, answer N. | |
118 | ||
df71837d TJ |
119 | config SECURITY_NETWORK_XFRM |
120 | bool "XFRM (IPSec) Networking Security Hooks" | |
121 | depends on XFRM && SECURITY_NETWORK | |
122 | help | |
123 | This enables the XFRM (IPSec) networking security hooks. | |
124 | If enabled, a security module can use these hooks to | |
125 | implement per-packet access controls based on labels | |
126 | derived from IPSec policy. Non-IPSec communications are | |
127 | designated as unlabelled, and only sockets authorized | |
128 | to communicate unlabelled data can send without using | |
129 | IPSec. | |
130 | If you are unsure how to answer this question, answer N. | |
1da177e4 | 131 | |
be6d3e56 KT |
132 | config SECURITY_PATH |
133 | bool "Security hooks for pathname based access control" | |
134 | depends on SECURITY | |
135 | help | |
136 | This enables the security hooks for pathname based access control. | |
137 | If enabled, a security module can use these hooks to | |
138 | implement pathname based access controls. | |
139 | If you are unsure how to answer this question, answer N. | |
140 | ||
31625340 JC |
141 | config INTEL_TXT |
142 | bool "Enable Intel(R) Trusted Execution Technology (Intel(R) TXT)" | |
69575d38 | 143 | depends on HAVE_INTEL_TXT |
31625340 JC |
144 | help |
145 | This option enables support for booting the kernel with the | |
146 | Trusted Boot (tboot) module. This will utilize | |
147 | Intel(R) Trusted Execution Technology to perform a measured launch | |
148 | of the kernel. If the system does not support Intel(R) TXT, this | |
149 | will have no effect. | |
150 | ||
3c556e41 | 151 | Intel TXT will provide higher assurance of system configuration and |
31625340 JC |
152 | initial state as well as data reset protection. This is used to |
153 | create a robust initial kernel measurement and verification, which | |
154 | helps to ensure that kernel security mechanisms are functioning | |
155 | correctly. This level of protection requires a root of trust outside | |
156 | of the kernel itself. | |
157 | ||
158 | Intel TXT also helps solve real end user concerns about having | |
159 | confidence that their hardware is running the VMM or kernel that | |
3c556e41 | 160 | it was configured with, especially since they may be responsible for |
31625340 JC |
161 | providing such assurances to VMs and services running on it. |
162 | ||
163 | See <http://www.intel.com/technology/security/> for more information | |
164 | about Intel(R) TXT. | |
165 | See <http://tboot.sourceforge.net> for more information about tboot. | |
166 | See Documentation/intel_txt.txt for a description of how to enable | |
167 | Intel TXT support in a kernel boot. | |
168 | ||
169 | If you are unsure as to whether this is required, answer N. | |
170 | ||
788084ab | 171 | config LSM_MMAP_MIN_ADDR |
024e6cb4 | 172 | int "Low address space for LSM to protect from user allocation" |
788084ab | 173 | depends on SECURITY && SECURITY_SELINUX |
530b099d | 174 | default 32768 if ARM || (ARM64 && COMPAT) |
a58578e4 | 175 | default 65536 |
788084ab EP |
176 | help |
177 | This is the portion of low virtual memory which should be protected | |
178 | from userspace allocation. Keeping a user from writing to low pages | |
179 | can help reduce the impact of kernel NULL pointer bugs. | |
180 | ||
181 | For most ia64, ppc64 and x86 users with lots of address space | |
182 | a value of 65536 is reasonable and should cause no problems. | |
183 | On arm and other archs it should not be higher than 32768. | |
184 | Programs which use vm86 functionality or have some need to map | |
185 | this low address space will need the permission specific to the | |
186 | systems running LSM. | |
187 | ||
f5509cc1 KC |
188 | config HAVE_HARDENED_USERCOPY_ALLOCATOR |
189 | bool | |
190 | help | |
191 | The heap allocator implements __check_heap_object() for | |
192 | validating memory ranges against heap object sizes in | |
193 | support of CONFIG_HARDENED_USERCOPY. | |
194 | ||
f5509cc1 KC |
195 | config HARDENED_USERCOPY |
196 | bool "Harden memory copies between kernel and userspace" | |
6040e576 | 197 | depends on HAVE_HARDENED_USERCOPY_ALLOCATOR |
f5509cc1 KC |
198 | select BUG |
199 | help | |
200 | This option checks for obviously wrong memory regions when | |
201 | copying memory to/from the kernel (via copy_to_user() and | |
202 | copy_from_user() functions) by rejecting memory ranges that | |
203 | are larger than the specified heap object, span multiple | |
99c55fb1 | 204 | separately allocated pages, are not on the process stack, |
f5509cc1 KC |
205 | or are part of the kernel text. This kills entire classes |
206 | of heap overflow exploits and similar kernel memory exposures. | |
207 | ||
8e1f74ea KC |
208 | config HARDENED_USERCOPY_PAGESPAN |
209 | bool "Refuse to copy allocations that span multiple pages" | |
210 | depends on HARDENED_USERCOPY | |
80a77045 | 211 | depends on EXPERT |
8e1f74ea KC |
212 | help |
213 | When a multi-page allocation is done without __GFP_COMP, | |
214 | hardened usercopy will reject attempts to copy it. There are, | |
215 | however, several cases of this in the kernel that have not all | |
216 | been removed. This config is intended to be used only while | |
217 | trying to find such users. | |
218 | ||
6974f0c4 DM |
219 | config FORTIFY_SOURCE |
220 | bool "Harden common str/mem functions against buffer overflows" | |
221 | depends on ARCH_HAS_FORTIFY_SOURCE | |
222 | help | |
223 | Detect overflows of buffers in common string and memory functions | |
224 | where the compiler can determine and validate the buffer sizes. | |
225 | ||
64e90a8a GKH |
226 | config STATIC_USERMODEHELPER |
227 | bool "Force all usermode helper calls through a single binary" | |
228 | help | |
229 | By default, the kernel can call many different userspace | |
230 | binary programs through the "usermode helper" kernel | |
231 | interface. Some of these binaries are statically defined | |
232 | either in the kernel code itself, or as a kernel configuration | |
233 | option. However, some of these are dynamically created at | |
234 | runtime, or can be modified after the kernel has started up. | |
235 | To provide an additional layer of security, route all of these | |
236 | calls through a single executable that can not have its name | |
237 | changed. | |
238 | ||
239 | Note, it is up to this single binary to then call the relevant | |
240 | "real" usermode helper binary, based on the first argument | |
241 | passed to it. If desired, this program can filter and pick | |
242 | and choose what real programs are called. | |
243 | ||
244 | If you wish for all usermode helper programs are to be | |
245 | disabled, choose this option and then set | |
246 | STATIC_USERMODEHELPER_PATH to an empty string. | |
247 | ||
248 | config STATIC_USERMODEHELPER_PATH | |
249 | string "Path to the static usermode helper binary" | |
250 | depends on STATIC_USERMODEHELPER | |
251 | default "/sbin/usermode-helper" | |
252 | help | |
253 | The binary called by the kernel when any usermode helper | |
254 | program is wish to be run. The "real" application's name will | |
255 | be in the first argument passed to this program on the command | |
256 | line. | |
257 | ||
258 | If you wish for all usermode helper programs to be disabled, | |
259 | specify an empty string here (i.e. ""). | |
260 | ||
99f9ef18 DH |
261 | config LOCK_DOWN_KERNEL |
262 | bool "Allow the kernel to be 'locked down'" | |
263 | help | |
264 | Allow the kernel to be locked down under certain circumstances, for | |
265 | instance if UEFI secure boot is enabled. Locking down the kernel | |
266 | turns off various features that might otherwise allow access to the | |
267 | kernel image (eg. setting MSR registers). | |
268 | ||
269 | config ALLOW_LOCKDOWN_LIFT | |
270 | bool | |
271 | help | |
272 | Allow the lockdown on a kernel to be lifted, thereby restoring the | |
273 | ability of userspace to access the kernel image (eg. by SysRq+x under | |
274 | x86). | |
275 | ||
1da177e4 | 276 | source security/selinux/Kconfig |
e114e473 | 277 | source security/smack/Kconfig |
00d7d6f8 | 278 | source security/tomoyo/Kconfig |
f9ad1af5 | 279 | source security/apparmor/Kconfig |
9b091556 | 280 | source security/loadpin/Kconfig |
2d514487 | 281 | source security/yama/Kconfig |
1da177e4 | 282 | |
f381c272 | 283 | source security/integrity/Kconfig |
3323eec9 | 284 | |
a3c3cde2 CS |
285 | menu "Security Module Selection" |
286 | visible if !SECURITY_STACKING | |
287 | ||
6e65f92f JJ |
288 | choice |
289 | prompt "Default security module" | |
290 | default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX | |
291 | default DEFAULT_SECURITY_SMACK if SECURITY_SMACK | |
292 | default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO | |
f9ad1af5 | 293 | default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR |
6e65f92f JJ |
294 | default DEFAULT_SECURITY_DAC |
295 | ||
296 | help | |
297 | Select the security module that will be used by default if the | |
298 | kernel parameter security= is not specified. | |
299 | ||
300 | config DEFAULT_SECURITY_SELINUX | |
301 | bool "SELinux" if SECURITY_SELINUX=y | |
302 | ||
303 | config DEFAULT_SECURITY_SMACK | |
304 | bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y | |
305 | ||
306 | config DEFAULT_SECURITY_TOMOYO | |
307 | bool "TOMOYO" if SECURITY_TOMOYO=y | |
308 | ||
f9ad1af5 JJ |
309 | config DEFAULT_SECURITY_APPARMOR |
310 | bool "AppArmor" if SECURITY_APPARMOR=y | |
311 | ||
6e65f92f JJ |
312 | config DEFAULT_SECURITY_DAC |
313 | bool "Unix Discretionary Access Controls" | |
314 | ||
315 | endchoice | |
316 | ||
317 | config DEFAULT_SECURITY | |
318 | string | |
319 | default "selinux" if DEFAULT_SECURITY_SELINUX | |
320 | default "smack" if DEFAULT_SECURITY_SMACK | |
321 | default "tomoyo" if DEFAULT_SECURITY_TOMOYO | |
f9ad1af5 | 322 | default "apparmor" if DEFAULT_SECURITY_APPARMOR |
6e65f92f JJ |
323 | default "" if DEFAULT_SECURITY_DAC |
324 | ||
1da177e4 LT |
325 | endmenu |
326 | ||
a3c3cde2 CS |
327 | menu "Security Module Stack" |
328 | visible if SECURITY_STACKING | |
329 | ||
330 | choice | |
bc7e09e5 JJ |
331 | prompt "mutually exclusive LSMs" |
332 | default SECURITY_NO_EXCLUSIVE_LSM | |
a3c3cde2 | 333 | |
bc7e09e5 JJ |
334 | config SECURITY_NO_EXCLUSIVE_LSM |
335 | bool "none" | |
336 | help | |
337 | Do no add an LSM to is mutually exclusive to the stack." | |
a3c3cde2 CS |
338 | config SECURITY_SELINUX_STACKED |
339 | bool "SELinux" if SECURITY_SELINUX=y | |
bc7e09e5 JJ |
340 | help |
341 | Add the SELinux security module to the stack. | |
342 | Please be sure your user space code is accomodating of | |
343 | this security module. | |
344 | Ensure that your network configuration is compatible | |
345 | with your combination of security modules. | |
346 | ||
347 | Incompatible with Smack being stacked. | |
348 | ||
349 | If you are unsure how to answer this question, answer N. | |
a3c3cde2 CS |
350 | |
351 | config SECURITY_SMACK_STACKED | |
352 | bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y | |
bc7e09e5 JJ |
353 | help |
354 | Add the Smack security module to the stack. | |
355 | Please be sure your user space code is accomodating of | |
356 | this security module. | |
357 | Ensure that your network configuration is compatible | |
358 | with your combination of security modules. | |
a3c3cde2 | 359 | |
bc7e09e5 | 360 | Incompatible with SeLinux being stacked. |
a3c3cde2 | 361 | |
bc7e09e5 | 362 | If you are unsure how to answer this question, answer N. |
a3c3cde2 CS |
363 | endchoice |
364 | ||
365 | config SECURITY_TOMOYO_STACKED | |
366 | bool "TOMOYO support is enabled by default" | |
367 | depends on SECURITY_TOMOYO && SECURITY_STACKING | |
368 | default n | |
369 | help | |
370 | This option instructs the system to use the TOMOYO checks. | |
371 | If not selected the module will not be invoked. | |
372 | Stacked security modules may interact in unexpected ways. | |
373 | Please be sure your user space code is accomodating of | |
374 | multiple security modules. | |
375 | ||
376 | If you are unsure how to answer this question, answer N. | |
377 | ||
378 | config SECURITY_APPARMOR_STACKED | |
379 | bool "AppArmor support is enabled by default" | |
380 | depends on SECURITY_APPARMOR && SECURITY_STACKING | |
381 | default n | |
382 | help | |
383 | This option instructs the system to use the AppArmor checks. | |
384 | If not selected the module will not be invoked. | |
385 | Stacked security modules may interact in unexpected ways. | |
386 | Please be sure your user space code is accomodating of | |
387 | multiple security modules. | |
388 | ||
389 | If you are unsure how to answer this question, answer N. | |
390 | ||
d637d5bd JJ |
391 | choice |
392 | prompt "Default LSM for legacy interfaces" | |
393 | default SECURITY_DEFAULT_DISPLAY_SELINUX if SECURITY_SELINUX_STACKED | |
394 | default SECURITY_DEFAULT_DISPLAY_SMACK if SECURITY_SMACK_STACKED | |
395 | default SECURITY_DEFAULT_DISPLAY_TOMOYO if SECURITY_TOMOYO_STACKED | |
396 | default SECURITY_DEFAULT_DISPALY_APPARMOR if SECURITY_APPARMOR_STACKED | |
397 | default SECURITY_DEFAULT_DISPLAY_FIRST | |
398 | ||
399 | help | |
400 | Select the security module context that will be displayed by | |
401 | default on legacy interfaces if the kernel parameter | |
402 | security.display= is not specified. | |
403 | ||
404 | config SECURITY_DEFAULT_DISPLAY_SELINUX | |
405 | bool "SELinux" if SECURITY_SELINUX=y | |
406 | ||
407 | config SECURITY_DEFAULT_DISPLAY_SMACK | |
408 | bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y | |
409 | ||
410 | config SECURITY_DEFAULT_DISPLAY_TOMOYO | |
411 | bool "TOMOYO" if SECURITY_TOMOYO=y | |
412 | ||
413 | config SECURITY_DEFAULT_DISPLAY_APPARMOR | |
414 | bool "AppArmor" if SECURITY_APPARMOR=y | |
415 | ||
416 | config SECURITY_DEFAULT_DISPLAY_FIRST | |
417 | bool "First security module to register" | |
418 | ||
419 | endchoice | |
420 | ||
421 | config SECURITY_DEFAULT_DISPLAY_NAME | |
422 | string | |
423 | default "selinux" if SECURITY_DEFAULT_DISPLAY_SELINUX | |
424 | default "smack" if SECURITY_DEFAULT_DISPLAY_SMACK | |
425 | default "tomoyo" if SECURITY_DEFAULT_DISPLAY_TOMOYO | |
426 | default "apparmor" if SECURITY_DEFAULT_DISPLAY_APPARMOR | |
427 | default "" if SECURITY_DEFAULT_DISPLAY_FIRST | |
428 | ||
a3c3cde2 CS |
429 | endmenu |
430 | ||
431 | endmenu |