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1 | # | |
2 | # Security configuration | |
3 | # | |
4 | ||
5 | menu "Security options" | |
6 | ||
7 | source security/keys/Kconfig | |
8 | ||
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 | ||
21 | config SECURITY | |
22 | bool "Enable different security models" | |
23 | depends on SYSFS | |
24 | depends on MULTIUSER | |
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 | ||
34 | config SECURITY_WRITABLE_HOOKS | |
35 | depends on SECURITY | |
36 | bool | |
37 | default n | |
38 | ||
39 | config SECURITYFS | |
40 | bool "Enable the securityfs filesystem" | |
41 | help | |
42 | This will build the securityfs filesystem. It is currently used by | |
43 | the TPM bios character driver and IMA, an integrity provider. It is | |
44 | not used by SELinux or SMACK. | |
45 | ||
46 | If you are unsure how to answer this question, answer N. | |
47 | ||
48 | config SECURITY_NETWORK | |
49 | bool "Socket and Networking Security Hooks" | |
50 | depends on SECURITY | |
51 | help | |
52 | This enables the socket and networking security hooks. | |
53 | If enabled, a security module can use these hooks to | |
54 | implement socket and networking access controls. | |
55 | If you are unsure how to answer this question, answer N. | |
56 | ||
57 | config PAGE_TABLE_ISOLATION | |
58 | bool "Remove the kernel mapping in user mode" | |
59 | default y | |
60 | depends on X86_64 && !UML | |
61 | help | |
62 | This feature reduces the number of hardware side channels by | |
63 | ensuring that the majority of kernel addresses are not mapped | |
64 | into userspace. | |
65 | ||
66 | See Documentation/x86/pagetable-isolation.txt for more details. | |
67 | ||
68 | config SECURITY_INFINIBAND | |
69 | bool "Infiniband Security Hooks" | |
70 | depends on SECURITY && INFINIBAND | |
71 | help | |
72 | This enables the Infiniband security hooks. | |
73 | If enabled, a security module can use these hooks to | |
74 | implement Infiniband access controls. | |
75 | If you are unsure how to answer this question, answer N. | |
76 | ||
77 | config SECURITY_NETWORK_XFRM | |
78 | bool "XFRM (IPSec) Networking Security Hooks" | |
79 | depends on XFRM && SECURITY_NETWORK | |
80 | help | |
81 | This enables the XFRM (IPSec) networking security hooks. | |
82 | If enabled, a security module can use these hooks to | |
83 | implement per-packet access controls based on labels | |
84 | derived from IPSec policy. Non-IPSec communications are | |
85 | designated as unlabelled, and only sockets authorized | |
86 | to communicate unlabelled data can send without using | |
87 | IPSec. | |
88 | If you are unsure how to answer this question, answer N. | |
89 | ||
90 | config SECURITY_PATH | |
91 | bool "Security hooks for pathname based access control" | |
92 | depends on SECURITY | |
93 | help | |
94 | This enables the security hooks for pathname based access control. | |
95 | If enabled, a security module can use these hooks to | |
96 | implement pathname based access controls. | |
97 | If you are unsure how to answer this question, answer N. | |
98 | ||
99 | config INTEL_TXT | |
100 | bool "Enable Intel(R) Trusted Execution Technology (Intel(R) TXT)" | |
101 | depends on HAVE_INTEL_TXT | |
102 | help | |
103 | This option enables support for booting the kernel with the | |
104 | Trusted Boot (tboot) module. This will utilize | |
105 | Intel(R) Trusted Execution Technology to perform a measured launch | |
106 | of the kernel. If the system does not support Intel(R) TXT, this | |
107 | will have no effect. | |
108 | ||
109 | Intel TXT will provide higher assurance of system configuration and | |
110 | initial state as well as data reset protection. This is used to | |
111 | create a robust initial kernel measurement and verification, which | |
112 | helps to ensure that kernel security mechanisms are functioning | |
113 | correctly. This level of protection requires a root of trust outside | |
114 | of the kernel itself. | |
115 | ||
116 | Intel TXT also helps solve real end user concerns about having | |
117 | confidence that their hardware is running the VMM or kernel that | |
118 | it was configured with, especially since they may be responsible for | |
119 | providing such assurances to VMs and services running on it. | |
120 | ||
121 | See <http://www.intel.com/technology/security/> for more information | |
122 | about Intel(R) TXT. | |
123 | See <http://tboot.sourceforge.net> for more information about tboot. | |
124 | See Documentation/intel_txt.txt for a description of how to enable | |
125 | Intel TXT support in a kernel boot. | |
126 | ||
127 | If you are unsure as to whether this is required, answer N. | |
128 | ||
129 | config LSM_MMAP_MIN_ADDR | |
130 | int "Low address space for LSM to protect from user allocation" | |
131 | depends on SECURITY && SECURITY_SELINUX | |
132 | default 32768 if ARM || (ARM64 && COMPAT) | |
133 | default 65536 | |
134 | help | |
135 | This is the portion of low virtual memory which should be protected | |
136 | from userspace allocation. Keeping a user from writing to low pages | |
137 | can help reduce the impact of kernel NULL pointer bugs. | |
138 | ||
139 | For most ia64, ppc64 and x86 users with lots of address space | |
140 | a value of 65536 is reasonable and should cause no problems. | |
141 | On arm and other archs it should not be higher than 32768. | |
142 | Programs which use vm86 functionality or have some need to map | |
143 | this low address space will need the permission specific to the | |
144 | systems running LSM. | |
145 | ||
146 | config HAVE_HARDENED_USERCOPY_ALLOCATOR | |
147 | bool | |
148 | help | |
149 | The heap allocator implements __check_heap_object() for | |
150 | validating memory ranges against heap object sizes in | |
151 | support of CONFIG_HARDENED_USERCOPY. | |
152 | ||
153 | config HARDENED_USERCOPY | |
154 | bool "Harden memory copies between kernel and userspace" | |
155 | depends on HAVE_HARDENED_USERCOPY_ALLOCATOR | |
156 | select BUG | |
157 | help | |
158 | This option checks for obviously wrong memory regions when | |
159 | copying memory to/from the kernel (via copy_to_user() and | |
160 | copy_from_user() functions) by rejecting memory ranges that | |
161 | are larger than the specified heap object, span multiple | |
162 | separately allocated pages, are not on the process stack, | |
163 | or are part of the kernel text. This kills entire classes | |
164 | of heap overflow exploits and similar kernel memory exposures. | |
165 | ||
166 | config HARDENED_USERCOPY_PAGESPAN | |
167 | bool "Refuse to copy allocations that span multiple pages" | |
168 | depends on HARDENED_USERCOPY | |
169 | depends on EXPERT | |
170 | help | |
171 | When a multi-page allocation is done without __GFP_COMP, | |
172 | hardened usercopy will reject attempts to copy it. There are, | |
173 | however, several cases of this in the kernel that have not all | |
174 | been removed. This config is intended to be used only while | |
175 | trying to find such users. | |
176 | ||
177 | config FORTIFY_SOURCE | |
178 | bool "Harden common str/mem functions against buffer overflows" | |
179 | depends on ARCH_HAS_FORTIFY_SOURCE | |
180 | help | |
181 | Detect overflows of buffers in common string and memory functions | |
182 | where the compiler can determine and validate the buffer sizes. | |
183 | ||
184 | config STATIC_USERMODEHELPER | |
185 | bool "Force all usermode helper calls through a single binary" | |
186 | help | |
187 | By default, the kernel can call many different userspace | |
188 | binary programs through the "usermode helper" kernel | |
189 | interface. Some of these binaries are statically defined | |
190 | either in the kernel code itself, or as a kernel configuration | |
191 | option. However, some of these are dynamically created at | |
192 | runtime, or can be modified after the kernel has started up. | |
193 | To provide an additional layer of security, route all of these | |
194 | calls through a single executable that can not have its name | |
195 | changed. | |
196 | ||
197 | Note, it is up to this single binary to then call the relevant | |
198 | "real" usermode helper binary, based on the first argument | |
199 | passed to it. If desired, this program can filter and pick | |
200 | and choose what real programs are called. | |
201 | ||
202 | If you wish for all usermode helper programs are to be | |
203 | disabled, choose this option and then set | |
204 | STATIC_USERMODEHELPER_PATH to an empty string. | |
205 | ||
206 | config STATIC_USERMODEHELPER_PATH | |
207 | string "Path to the static usermode helper binary" | |
208 | depends on STATIC_USERMODEHELPER | |
209 | default "/sbin/usermode-helper" | |
210 | help | |
211 | The binary called by the kernel when any usermode helper | |
212 | program is wish to be run. The "real" application's name will | |
213 | be in the first argument passed to this program on the command | |
214 | line. | |
215 | ||
216 | If you wish for all usermode helper programs to be disabled, | |
217 | specify an empty string here (i.e. ""). | |
218 | ||
219 | source security/selinux/Kconfig | |
220 | source security/smack/Kconfig | |
221 | source security/tomoyo/Kconfig | |
222 | source security/apparmor/Kconfig | |
223 | source security/loadpin/Kconfig | |
224 | source security/yama/Kconfig | |
225 | ||
226 | source security/integrity/Kconfig | |
227 | ||
228 | choice | |
229 | prompt "Default security module" | |
230 | default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX | |
231 | default DEFAULT_SECURITY_SMACK if SECURITY_SMACK | |
232 | default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO | |
233 | default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR | |
234 | default DEFAULT_SECURITY_DAC | |
235 | ||
236 | help | |
237 | Select the security module that will be used by default if the | |
238 | kernel parameter security= is not specified. | |
239 | ||
240 | config DEFAULT_SECURITY_SELINUX | |
241 | bool "SELinux" if SECURITY_SELINUX=y | |
242 | ||
243 | config DEFAULT_SECURITY_SMACK | |
244 | bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y | |
245 | ||
246 | config DEFAULT_SECURITY_TOMOYO | |
247 | bool "TOMOYO" if SECURITY_TOMOYO=y | |
248 | ||
249 | config DEFAULT_SECURITY_APPARMOR | |
250 | bool "AppArmor" if SECURITY_APPARMOR=y | |
251 | ||
252 | config DEFAULT_SECURITY_DAC | |
253 | bool "Unix Discretionary Access Controls" | |
254 | ||
255 | endchoice | |
256 | ||
257 | config DEFAULT_SECURITY | |
258 | string | |
259 | default "selinux" if DEFAULT_SECURITY_SELINUX | |
260 | default "smack" if DEFAULT_SECURITY_SMACK | |
261 | default "tomoyo" if DEFAULT_SECURITY_TOMOYO | |
262 | default "apparmor" if DEFAULT_SECURITY_APPARMOR | |
263 | default "" if DEFAULT_SECURITY_DAC | |
264 | ||
265 | endmenu | |
266 |