Commit | Line | Data |
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1da177e4 LT |
1 | # |
2 | # Security configuration | |
3 | # | |
4 | ||
5 | menu "Security options" | |
6 | ||
8636a1f9 | 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 | ||
1da177e4 LT |
21 | config SECURITY |
22 | bool "Enable different security models" | |
2c40579b | 23 | depends on SYSFS |
2813893f | 24 | depends on MULTIUSER |
1da177e4 LT |
25 | help |
26 | This allows you to choose different security modules to be | |
27 | configured into your kernel. | |
28 | ||
29 | If this option is not selected, the default Linux security | |
30 | model will be used. | |
31 | ||
32 | If you are unsure how to answer this question, answer N. | |
33 | ||
dd0859dc JM |
34 | config SECURITY_WRITABLE_HOOKS |
35 | depends on SECURITY | |
36 | bool | |
37 | default n | |
38 | ||
da31894e EP |
39 | config SECURITYFS |
40 | bool "Enable the securityfs filesystem" | |
41 | help | |
42 | This will build the securityfs filesystem. It is currently used by | |
b102c11e | 43 | various security modules (AppArmor, IMA, SafeSetID, TOMOYO, TPM). |
da31894e EP |
44 | |
45 | If you are unsure how to answer this question, answer N. | |
46 | ||
1da177e4 LT |
47 | config SECURITY_NETWORK |
48 | bool "Socket and Networking Security Hooks" | |
49 | depends on SECURITY | |
50 | help | |
51 | This enables the socket and networking security hooks. | |
52 | If enabled, a security module can use these hooks to | |
53 | implement socket and networking access controls. | |
54 | If you are unsure how to answer this question, answer N. | |
df71837d | 55 | |
385ce0ea DH |
56 | config PAGE_TABLE_ISOLATION |
57 | bool "Remove the kernel mapping in user mode" | |
87faa0d9 | 58 | default y |
61a6bd83 | 59 | depends on (X86_64 || X86_PAE) && !UML |
385ce0ea DH |
60 | help |
61 | This feature reduces the number of hardware side channels by | |
62 | ensuring that the majority of kernel addresses are not mapped | |
63 | into userspace. | |
64 | ||
a237f762 | 65 | See Documentation/x86/pti.txt for more details. |
385ce0ea | 66 | |
d291f1a6 DJ |
67 | config SECURITY_INFINIBAND |
68 | bool "Infiniband Security Hooks" | |
69 | depends on SECURITY && INFINIBAND | |
70 | help | |
71 | This enables the Infiniband security hooks. | |
72 | If enabled, a security module can use these hooks to | |
73 | implement Infiniband access controls. | |
74 | If you are unsure how to answer this question, answer N. | |
75 | ||
df71837d TJ |
76 | config SECURITY_NETWORK_XFRM |
77 | bool "XFRM (IPSec) Networking Security Hooks" | |
78 | depends on XFRM && SECURITY_NETWORK | |
79 | help | |
80 | This enables the XFRM (IPSec) networking security hooks. | |
81 | If enabled, a security module can use these hooks to | |
82 | implement per-packet access controls based on labels | |
83 | derived from IPSec policy. Non-IPSec communications are | |
84 | designated as unlabelled, and only sockets authorized | |
85 | to communicate unlabelled data can send without using | |
86 | IPSec. | |
87 | If you are unsure how to answer this question, answer N. | |
1da177e4 | 88 | |
be6d3e56 KT |
89 | config SECURITY_PATH |
90 | bool "Security hooks for pathname based access control" | |
91 | depends on SECURITY | |
92 | help | |
93 | This enables the security hooks for pathname based access control. | |
94 | If enabled, a security module can use these hooks to | |
95 | implement pathname based access controls. | |
96 | If you are unsure how to answer this question, answer N. | |
97 | ||
31625340 JC |
98 | config INTEL_TXT |
99 | bool "Enable Intel(R) Trusted Execution Technology (Intel(R) TXT)" | |
69575d38 | 100 | depends on HAVE_INTEL_TXT |
31625340 JC |
101 | help |
102 | This option enables support for booting the kernel with the | |
103 | Trusted Boot (tboot) module. This will utilize | |
104 | Intel(R) Trusted Execution Technology to perform a measured launch | |
105 | of the kernel. If the system does not support Intel(R) TXT, this | |
106 | will have no effect. | |
107 | ||
3c556e41 | 108 | Intel TXT will provide higher assurance of system configuration and |
31625340 JC |
109 | initial state as well as data reset protection. This is used to |
110 | create a robust initial kernel measurement and verification, which | |
111 | helps to ensure that kernel security mechanisms are functioning | |
112 | correctly. This level of protection requires a root of trust outside | |
113 | of the kernel itself. | |
114 | ||
115 | Intel TXT also helps solve real end user concerns about having | |
116 | confidence that their hardware is running the VMM or kernel that | |
3c556e41 | 117 | it was configured with, especially since they may be responsible for |
31625340 JC |
118 | providing such assurances to VMs and services running on it. |
119 | ||
120 | See <http://www.intel.com/technology/security/> for more information | |
121 | about Intel(R) TXT. | |
122 | See <http://tboot.sourceforge.net> for more information about tboot. | |
123 | See Documentation/intel_txt.txt for a description of how to enable | |
124 | Intel TXT support in a kernel boot. | |
125 | ||
126 | If you are unsure as to whether this is required, answer N. | |
127 | ||
788084ab | 128 | config LSM_MMAP_MIN_ADDR |
024e6cb4 | 129 | int "Low address space for LSM to protect from user allocation" |
788084ab | 130 | depends on SECURITY && SECURITY_SELINUX |
530b099d | 131 | default 32768 if ARM || (ARM64 && COMPAT) |
a58578e4 | 132 | default 65536 |
788084ab EP |
133 | help |
134 | This is the portion of low virtual memory which should be protected | |
135 | from userspace allocation. Keeping a user from writing to low pages | |
136 | can help reduce the impact of kernel NULL pointer bugs. | |
137 | ||
138 | For most ia64, ppc64 and x86 users with lots of address space | |
139 | a value of 65536 is reasonable and should cause no problems. | |
140 | On arm and other archs it should not be higher than 32768. | |
141 | Programs which use vm86 functionality or have some need to map | |
142 | this low address space will need the permission specific to the | |
143 | systems running LSM. | |
144 | ||
f5509cc1 KC |
145 | config HAVE_HARDENED_USERCOPY_ALLOCATOR |
146 | bool | |
147 | help | |
148 | The heap allocator implements __check_heap_object() for | |
149 | validating memory ranges against heap object sizes in | |
150 | support of CONFIG_HARDENED_USERCOPY. | |
151 | ||
f5509cc1 KC |
152 | config HARDENED_USERCOPY |
153 | bool "Harden memory copies between kernel and userspace" | |
6040e576 | 154 | depends on HAVE_HARDENED_USERCOPY_ALLOCATOR |
22ec1a2a | 155 | imply STRICT_DEVMEM |
f5509cc1 KC |
156 | help |
157 | This option checks for obviously wrong memory regions when | |
158 | copying memory to/from the kernel (via copy_to_user() and | |
159 | copy_from_user() functions) by rejecting memory ranges that | |
160 | are larger than the specified heap object, span multiple | |
99c55fb1 | 161 | separately allocated pages, are not on the process stack, |
f5509cc1 KC |
162 | or are part of the kernel text. This kills entire classes |
163 | of heap overflow exploits and similar kernel memory exposures. | |
164 | ||
2d891fbc KC |
165 | config HARDENED_USERCOPY_FALLBACK |
166 | bool "Allow usercopy whitelist violations to fallback to object size" | |
167 | depends on HARDENED_USERCOPY | |
168 | default y | |
169 | help | |
170 | This is a temporary option that allows missing usercopy whitelists | |
171 | to be discovered via a WARN() to the kernel log, instead of | |
172 | rejecting the copy, falling back to non-whitelisted hardened | |
173 | usercopy that checks the slab allocation size instead of the | |
174 | whitelist size. This option will be removed once it seems like | |
175 | all missing usercopy whitelists have been identified and fixed. | |
176 | Booting with "slab_common.usercopy_fallback=Y/N" can change | |
177 | this setting. | |
178 | ||
8e1f74ea KC |
179 | config HARDENED_USERCOPY_PAGESPAN |
180 | bool "Refuse to copy allocations that span multiple pages" | |
181 | depends on HARDENED_USERCOPY | |
80a77045 | 182 | depends on EXPERT |
8e1f74ea KC |
183 | help |
184 | When a multi-page allocation is done without __GFP_COMP, | |
185 | hardened usercopy will reject attempts to copy it. There are, | |
186 | however, several cases of this in the kernel that have not all | |
187 | been removed. This config is intended to be used only while | |
188 | trying to find such users. | |
189 | ||
6974f0c4 DM |
190 | config FORTIFY_SOURCE |
191 | bool "Harden common str/mem functions against buffer overflows" | |
192 | depends on ARCH_HAS_FORTIFY_SOURCE | |
193 | help | |
194 | Detect overflows of buffers in common string and memory functions | |
195 | where the compiler can determine and validate the buffer sizes. | |
196 | ||
64e90a8a GKH |
197 | config STATIC_USERMODEHELPER |
198 | bool "Force all usermode helper calls through a single binary" | |
199 | help | |
200 | By default, the kernel can call many different userspace | |
201 | binary programs through the "usermode helper" kernel | |
202 | interface. Some of these binaries are statically defined | |
203 | either in the kernel code itself, or as a kernel configuration | |
204 | option. However, some of these are dynamically created at | |
205 | runtime, or can be modified after the kernel has started up. | |
206 | To provide an additional layer of security, route all of these | |
207 | calls through a single executable that can not have its name | |
208 | changed. | |
209 | ||
210 | Note, it is up to this single binary to then call the relevant | |
211 | "real" usermode helper binary, based on the first argument | |
212 | passed to it. If desired, this program can filter and pick | |
213 | and choose what real programs are called. | |
214 | ||
215 | If you wish for all usermode helper programs are to be | |
216 | disabled, choose this option and then set | |
217 | STATIC_USERMODEHELPER_PATH to an empty string. | |
218 | ||
219 | config STATIC_USERMODEHELPER_PATH | |
220 | string "Path to the static usermode helper binary" | |
221 | depends on STATIC_USERMODEHELPER | |
222 | default "/sbin/usermode-helper" | |
223 | help | |
224 | The binary called by the kernel when any usermode helper | |
225 | program is wish to be run. The "real" application's name will | |
226 | be in the first argument passed to this program on the command | |
227 | line. | |
228 | ||
229 | If you wish for all usermode helper programs to be disabled, | |
230 | specify an empty string here (i.e. ""). | |
231 | ||
8636a1f9 MY |
232 | source "security/selinux/Kconfig" |
233 | source "security/smack/Kconfig" | |
234 | source "security/tomoyo/Kconfig" | |
235 | source "security/apparmor/Kconfig" | |
236 | source "security/loadpin/Kconfig" | |
237 | source "security/yama/Kconfig" | |
aeca4e2c | 238 | source "security/safesetid/Kconfig" |
1da177e4 | 239 | |
8636a1f9 | 240 | source "security/integrity/Kconfig" |
3323eec9 | 241 | |
2623c4fb KC |
242 | choice |
243 | prompt "First legacy 'major LSM' to be initialized" | |
244 | default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX | |
245 | default DEFAULT_SECURITY_SMACK if SECURITY_SMACK | |
246 | default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO | |
247 | default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR | |
248 | default DEFAULT_SECURITY_DAC | |
249 | ||
250 | help | |
251 | This choice is there only for converting CONFIG_DEFAULT_SECURITY | |
252 | in old kernel configs to CONFIG_LSM in new kernel configs. Don't | |
253 | change this choice unless you are creating a fresh kernel config, | |
254 | for this choice will be ignored after CONFIG_LSM has been set. | |
255 | ||
256 | Selects the legacy "major security module" that will be | |
257 | initialized first. Overridden by non-default CONFIG_LSM. | |
258 | ||
259 | config DEFAULT_SECURITY_SELINUX | |
260 | bool "SELinux" if SECURITY_SELINUX=y | |
261 | ||
262 | config DEFAULT_SECURITY_SMACK | |
263 | bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y | |
264 | ||
265 | config DEFAULT_SECURITY_TOMOYO | |
266 | bool "TOMOYO" if SECURITY_TOMOYO=y | |
267 | ||
268 | config DEFAULT_SECURITY_APPARMOR | |
269 | bool "AppArmor" if SECURITY_APPARMOR=y | |
270 | ||
271 | config DEFAULT_SECURITY_DAC | |
272 | bool "Unix Discretionary Access Controls" | |
273 | ||
274 | endchoice | |
275 | ||
13e735c0 KC |
276 | config LSM |
277 | string "Ordered list of enabled LSMs" | |
2623c4fb KC |
278 | default "yama,loadpin,safesetid,integrity,smack,selinux,tomoyo,apparmor" if DEFAULT_SECURITY_SMACK |
279 | default "yama,loadpin,safesetid,integrity,apparmor,selinux,smack,tomoyo" if DEFAULT_SECURITY_APPARMOR | |
280 | default "yama,loadpin,safesetid,integrity,tomoyo" if DEFAULT_SECURITY_TOMOYO | |
281 | default "yama,loadpin,safesetid,integrity" if DEFAULT_SECURITY_DAC | |
aeca4e2c | 282 | default "yama,loadpin,safesetid,integrity,selinux,smack,tomoyo,apparmor" |
13e735c0 KC |
283 | help |
284 | A comma-separated list of LSMs, in initialization order. | |
79f7865d KC |
285 | Any LSMs left off this list will be ignored. This can be |
286 | controlled at boot with the "lsm=" parameter. | |
13e735c0 KC |
287 | |
288 | If unsure, leave this as the default. | |
289 | ||
1da177e4 LT |
290 | endmenu |
291 |