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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 | ||
98738d70 CS |
48 | config SECURITY_LSM_DEBUG |
49 | bool "Enable debugging of the LSM infrastructure" | |
50 | depends on SECURITY | |
51 | help | |
52 | This allows you to choose debug messages related to | |
53 | security modules configured into your kernel. These | |
54 | messages may be helpful in determining how a security | |
55 | module is using security blobs. | |
56 | ||
57 | If you are unsure how to answer this question, answer N. | |
58 | ||
da31894e EP |
59 | config SECURITYFS |
60 | bool "Enable the securityfs filesystem" | |
61 | help | |
62 | This will build the securityfs filesystem. It is currently used by | |
3323eec9 MZ |
63 | the TPM bios character driver and IMA, an integrity provider. It is |
64 | not used by SELinux or SMACK. | |
da31894e EP |
65 | |
66 | If you are unsure how to answer this question, answer N. | |
67 | ||
1da177e4 LT |
68 | config SECURITY_NETWORK |
69 | bool "Socket and Networking Security Hooks" | |
70 | depends on SECURITY | |
71 | help | |
72 | This enables the socket and networking security hooks. | |
73 | If enabled, a security module can use these hooks to | |
74 | implement socket and networking access controls. | |
75 | If you are unsure how to answer this question, answer N. | |
df71837d | 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. | |
133 | See Documentation/intel_txt.txt for a description of how to enable | |
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 |
f5509cc1 KC |
165 | select BUG |
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 | ||
8e1f74ea KC |
175 | config HARDENED_USERCOPY_PAGESPAN |
176 | bool "Refuse to copy allocations that span multiple pages" | |
177 | depends on HARDENED_USERCOPY | |
80a77045 | 178 | depends on EXPERT |
8e1f74ea KC |
179 | help |
180 | When a multi-page allocation is done without __GFP_COMP, | |
181 | hardened usercopy will reject attempts to copy it. There are, | |
182 | however, several cases of this in the kernel that have not all | |
183 | been removed. This config is intended to be used only while | |
184 | trying to find such users. | |
185 | ||
6974f0c4 DM |
186 | config FORTIFY_SOURCE |
187 | bool "Harden common str/mem functions against buffer overflows" | |
188 | depends on ARCH_HAS_FORTIFY_SOURCE | |
189 | help | |
190 | Detect overflows of buffers in common string and memory functions | |
191 | where the compiler can determine and validate the buffer sizes. | |
192 | ||
64e90a8a GKH |
193 | config STATIC_USERMODEHELPER |
194 | bool "Force all usermode helper calls through a single binary" | |
195 | help | |
196 | By default, the kernel can call many different userspace | |
197 | binary programs through the "usermode helper" kernel | |
198 | interface. Some of these binaries are statically defined | |
199 | either in the kernel code itself, or as a kernel configuration | |
200 | option. However, some of these are dynamically created at | |
201 | runtime, or can be modified after the kernel has started up. | |
202 | To provide an additional layer of security, route all of these | |
203 | calls through a single executable that can not have its name | |
204 | changed. | |
205 | ||
206 | Note, it is up to this single binary to then call the relevant | |
207 | "real" usermode helper binary, based on the first argument | |
208 | passed to it. If desired, this program can filter and pick | |
209 | and choose what real programs are called. | |
210 | ||
211 | If you wish for all usermode helper programs are to be | |
212 | disabled, choose this option and then set | |
213 | STATIC_USERMODEHELPER_PATH to an empty string. | |
214 | ||
215 | config STATIC_USERMODEHELPER_PATH | |
216 | string "Path to the static usermode helper binary" | |
217 | depends on STATIC_USERMODEHELPER | |
218 | default "/sbin/usermode-helper" | |
219 | help | |
220 | The binary called by the kernel when any usermode helper | |
221 | program is wish to be run. The "real" application's name will | |
222 | be in the first argument passed to this program on the command | |
223 | line. | |
224 | ||
225 | If you wish for all usermode helper programs to be disabled, | |
226 | specify an empty string here (i.e. ""). | |
227 | ||
99f9ef18 DH |
228 | config LOCK_DOWN_KERNEL |
229 | bool "Allow the kernel to be 'locked down'" | |
230 | help | |
231 | Allow the kernel to be locked down under certain circumstances, for | |
232 | instance if UEFI secure boot is enabled. Locking down the kernel | |
233 | turns off various features that might otherwise allow access to the | |
234 | kernel image (eg. setting MSR registers). | |
235 | ||
236 | config ALLOW_LOCKDOWN_LIFT | |
237 | bool | |
238 | help | |
239 | Allow the lockdown on a kernel to be lifted, thereby restoring the | |
240 | ability of userspace to access the kernel image (eg. by SysRq+x under | |
241 | x86). | |
242 | ||
1da177e4 | 243 | source security/selinux/Kconfig |
e114e473 | 244 | source security/smack/Kconfig |
00d7d6f8 | 245 | source security/tomoyo/Kconfig |
f9ad1af5 | 246 | source security/apparmor/Kconfig |
9b091556 | 247 | source security/loadpin/Kconfig |
2d514487 | 248 | source security/yama/Kconfig |
1da177e4 | 249 | |
f381c272 | 250 | source security/integrity/Kconfig |
3323eec9 | 251 | |
6e65f92f JJ |
252 | choice |
253 | prompt "Default security module" | |
254 | default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX | |
255 | default DEFAULT_SECURITY_SMACK if SECURITY_SMACK | |
256 | default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO | |
f9ad1af5 | 257 | default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR |
6e65f92f JJ |
258 | default DEFAULT_SECURITY_DAC |
259 | ||
260 | help | |
261 | Select the security module that will be used by default if the | |
262 | kernel parameter security= is not specified. | |
263 | ||
264 | config DEFAULT_SECURITY_SELINUX | |
265 | bool "SELinux" if SECURITY_SELINUX=y | |
266 | ||
267 | config DEFAULT_SECURITY_SMACK | |
268 | bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y | |
269 | ||
270 | config DEFAULT_SECURITY_TOMOYO | |
271 | bool "TOMOYO" if SECURITY_TOMOYO=y | |
272 | ||
f9ad1af5 JJ |
273 | config DEFAULT_SECURITY_APPARMOR |
274 | bool "AppArmor" if SECURITY_APPARMOR=y | |
275 | ||
6e65f92f JJ |
276 | config DEFAULT_SECURITY_DAC |
277 | bool "Unix Discretionary Access Controls" | |
278 | ||
279 | endchoice | |
280 | ||
281 | config DEFAULT_SECURITY | |
282 | string | |
283 | default "selinux" if DEFAULT_SECURITY_SELINUX | |
284 | default "smack" if DEFAULT_SECURITY_SMACK | |
285 | default "tomoyo" if DEFAULT_SECURITY_TOMOYO | |
f9ad1af5 | 286 | default "apparmor" if DEFAULT_SECURITY_APPARMOR |
6e65f92f JJ |
287 | default "" if DEFAULT_SECURITY_DAC |
288 | ||
1da177e4 LT |
289 | endmenu |
290 |