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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 | ||
eb4b335d JVS |
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 | ||
da31894e EP |
48 | config SECURITYFS |
49 | bool "Enable the securityfs filesystem" | |
50 | help | |
51 | This will build the securityfs filesystem. It is currently used by | |
3323eec9 MZ |
52 | the TPM bios character driver and IMA, an integrity provider. It is |
53 | not used by SELinux or SMACK. | |
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 | |
3dfd9fd8 DH |
66 | config PAGE_TABLE_ISOLATION |
67 | bool "Remove the kernel mapping in user mode" | |
68 | depends on X86_64 && !UML | |
69 | default y | |
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 | ||
c3e7fc96 | 75 | See Documentation/x86/pti.txt for more details. |
3dfd9fd8 | 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 | 165 | select BUG |
ea60e54b | 166 | imply STRICT_DEVMEM |
f5509cc1 KC |
167 | help |
168 | This option checks for obviously wrong memory regions when | |
169 | copying memory to/from the kernel (via copy_to_user() and | |
170 | copy_from_user() functions) by rejecting memory ranges that | |
171 | are larger than the specified heap object, span multiple | |
99c55fb1 | 172 | separately allocated pages, are not on the process stack, |
f5509cc1 KC |
173 | or are part of the kernel text. This kills entire classes |
174 | of heap overflow exploits and similar kernel memory exposures. | |
175 | ||
8e1f74ea KC |
176 | config HARDENED_USERCOPY_PAGESPAN |
177 | bool "Refuse to copy allocations that span multiple pages" | |
178 | depends on HARDENED_USERCOPY | |
80a77045 | 179 | depends on EXPERT |
8e1f74ea KC |
180 | help |
181 | When a multi-page allocation is done without __GFP_COMP, | |
182 | hardened usercopy will reject attempts to copy it. There are, | |
183 | however, several cases of this in the kernel that have not all | |
184 | been removed. This config is intended to be used only while | |
185 | trying to find such users. | |
186 | ||
6974f0c4 DM |
187 | config FORTIFY_SOURCE |
188 | bool "Harden common str/mem functions against buffer overflows" | |
189 | depends on ARCH_HAS_FORTIFY_SOURCE | |
190 | help | |
191 | Detect overflows of buffers in common string and memory functions | |
192 | where the compiler can determine and validate the buffer sizes. | |
193 | ||
64e90a8a GKH |
194 | config STATIC_USERMODEHELPER |
195 | bool "Force all usermode helper calls through a single binary" | |
196 | help | |
197 | By default, the kernel can call many different userspace | |
198 | binary programs through the "usermode helper" kernel | |
199 | interface. Some of these binaries are statically defined | |
200 | either in the kernel code itself, or as a kernel configuration | |
201 | option. However, some of these are dynamically created at | |
202 | runtime, or can be modified after the kernel has started up. | |
203 | To provide an additional layer of security, route all of these | |
204 | calls through a single executable that can not have its name | |
205 | changed. | |
206 | ||
207 | Note, it is up to this single binary to then call the relevant | |
208 | "real" usermode helper binary, based on the first argument | |
209 | passed to it. If desired, this program can filter and pick | |
210 | and choose what real programs are called. | |
211 | ||
212 | If you wish for all usermode helper programs are to be | |
213 | disabled, choose this option and then set | |
214 | STATIC_USERMODEHELPER_PATH to an empty string. | |
215 | ||
216 | config STATIC_USERMODEHELPER_PATH | |
217 | string "Path to the static usermode helper binary" | |
218 | depends on STATIC_USERMODEHELPER | |
219 | default "/sbin/usermode-helper" | |
220 | help | |
221 | The binary called by the kernel when any usermode helper | |
222 | program is wish to be run. The "real" application's name will | |
223 | be in the first argument passed to this program on the command | |
224 | line. | |
225 | ||
226 | If you wish for all usermode helper programs to be disabled, | |
227 | specify an empty string here (i.e. ""). | |
228 | ||
1da177e4 | 229 | source security/selinux/Kconfig |
e114e473 | 230 | source security/smack/Kconfig |
00d7d6f8 | 231 | source security/tomoyo/Kconfig |
f9ad1af5 | 232 | source security/apparmor/Kconfig |
9b091556 | 233 | source security/loadpin/Kconfig |
2d514487 | 234 | source security/yama/Kconfig |
1da177e4 | 235 | |
f381c272 | 236 | source security/integrity/Kconfig |
3323eec9 | 237 | |
6e65f92f JJ |
238 | choice |
239 | prompt "Default security module" | |
240 | default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX | |
241 | default DEFAULT_SECURITY_SMACK if SECURITY_SMACK | |
242 | default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO | |
f9ad1af5 | 243 | default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR |
6e65f92f JJ |
244 | default DEFAULT_SECURITY_DAC |
245 | ||
246 | help | |
247 | Select the security module that will be used by default if the | |
248 | kernel parameter security= is not specified. | |
249 | ||
250 | config DEFAULT_SECURITY_SELINUX | |
251 | bool "SELinux" if SECURITY_SELINUX=y | |
252 | ||
253 | config DEFAULT_SECURITY_SMACK | |
254 | bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y | |
255 | ||
256 | config DEFAULT_SECURITY_TOMOYO | |
257 | bool "TOMOYO" if SECURITY_TOMOYO=y | |
258 | ||
f9ad1af5 JJ |
259 | config DEFAULT_SECURITY_APPARMOR |
260 | bool "AppArmor" if SECURITY_APPARMOR=y | |
261 | ||
6e65f92f JJ |
262 | config DEFAULT_SECURITY_DAC |
263 | bool "Unix Discretionary Access Controls" | |
264 | ||
265 | endchoice | |
266 | ||
267 | config DEFAULT_SECURITY | |
268 | string | |
269 | default "selinux" if DEFAULT_SECURITY_SELINUX | |
270 | default "smack" if DEFAULT_SECURITY_SMACK | |
271 | default "tomoyo" if DEFAULT_SECURITY_TOMOYO | |
f9ad1af5 | 272 | default "apparmor" if DEFAULT_SECURITY_APPARMOR |
6e65f92f JJ |
273 | default "" if DEFAULT_SECURITY_DAC |
274 | ||
1da177e4 LT |
275 | endmenu |
276 |