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ec8f24b7 | 1 | # SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | # |
3 | # Security configuration | |
4 | # | |
5 | ||
6 | menu "Security options" | |
7 | ||
8636a1f9 | 8 | source "security/keys/Kconfig" |
1da177e4 | 9 | |
eaf06b24 DR |
10 | config SECURITY_DMESG_RESTRICT |
11 | bool "Restrict unprivileged access to the kernel syslog" | |
12 | default n | |
13 | help | |
14 | This enforces restrictions on unprivileged users reading the kernel | |
15 | syslog via dmesg(8). | |
16 | ||
17 | If this option is not selected, no restrictions will be enforced | |
18 | unless the dmesg_restrict sysctl is explicitly set to (1). | |
19 | ||
20 | If you are unsure how to answer this question, answer N. | |
21 | ||
1da177e4 LT |
22 | config SECURITY |
23 | bool "Enable different security models" | |
2c40579b | 24 | depends on SYSFS |
2813893f | 25 | depends on MULTIUSER |
1da177e4 LT |
26 | help |
27 | This allows you to choose different security modules to be | |
28 | configured into your kernel. | |
29 | ||
30 | If this option is not selected, the default Linux security | |
31 | model will be used. | |
32 | ||
33 | If you are unsure how to answer this question, answer N. | |
34 | ||
dd0859dc JM |
35 | config SECURITY_WRITABLE_HOOKS |
36 | depends on SECURITY | |
37 | bool | |
38 | default n | |
39 | ||
da31894e EP |
40 | config SECURITYFS |
41 | bool "Enable the securityfs filesystem" | |
42 | help | |
43 | This will build the securityfs filesystem. It is currently used by | |
b102c11e | 44 | various security modules (AppArmor, IMA, SafeSetID, TOMOYO, TPM). |
da31894e EP |
45 | |
46 | If you are unsure how to answer this question, answer N. | |
47 | ||
1da177e4 LT |
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. | |
df71837d | 56 | |
d291f1a6 DJ |
57 | config SECURITY_INFINIBAND |
58 | bool "Infiniband Security Hooks" | |
59 | depends on SECURITY && INFINIBAND | |
60 | help | |
61 | This enables the Infiniband security hooks. | |
62 | If enabled, a security module can use these hooks to | |
63 | implement Infiniband access controls. | |
64 | If you are unsure how to answer this question, answer N. | |
65 | ||
df71837d TJ |
66 | config SECURITY_NETWORK_XFRM |
67 | bool "XFRM (IPSec) Networking Security Hooks" | |
68 | depends on XFRM && SECURITY_NETWORK | |
69 | help | |
70 | This enables the XFRM (IPSec) networking security hooks. | |
71 | If enabled, a security module can use these hooks to | |
72 | implement per-packet access controls based on labels | |
73 | derived from IPSec policy. Non-IPSec communications are | |
74 | designated as unlabelled, and only sockets authorized | |
75 | to communicate unlabelled data can send without using | |
76 | IPSec. | |
77 | If you are unsure how to answer this question, answer N. | |
1da177e4 | 78 | |
be6d3e56 KT |
79 | config SECURITY_PATH |
80 | bool "Security hooks for pathname based access control" | |
81 | depends on SECURITY | |
82 | help | |
83 | This enables the security hooks for pathname based access control. | |
84 | If enabled, a security module can use these hooks to | |
85 | implement pathname based access controls. | |
86 | If you are unsure how to answer this question, answer N. | |
87 | ||
31625340 JC |
88 | config INTEL_TXT |
89 | bool "Enable Intel(R) Trusted Execution Technology (Intel(R) TXT)" | |
69575d38 | 90 | depends on HAVE_INTEL_TXT |
31625340 JC |
91 | help |
92 | This option enables support for booting the kernel with the | |
93 | Trusted Boot (tboot) module. This will utilize | |
94 | Intel(R) Trusted Execution Technology to perform a measured launch | |
95 | of the kernel. If the system does not support Intel(R) TXT, this | |
96 | will have no effect. | |
97 | ||
3c556e41 | 98 | Intel TXT will provide higher assurance of system configuration and |
31625340 JC |
99 | initial state as well as data reset protection. This is used to |
100 | create a robust initial kernel measurement and verification, which | |
101 | helps to ensure that kernel security mechanisms are functioning | |
102 | correctly. This level of protection requires a root of trust outside | |
103 | of the kernel itself. | |
104 | ||
105 | Intel TXT also helps solve real end user concerns about having | |
106 | confidence that their hardware is running the VMM or kernel that | |
3c556e41 | 107 | it was configured with, especially since they may be responsible for |
31625340 JC |
108 | providing such assurances to VMs and services running on it. |
109 | ||
c9fecf50 | 110 | See <https://www.intel.com/technology/security/> for more information |
31625340 JC |
111 | about Intel(R) TXT. |
112 | See <http://tboot.sourceforge.net> for more information about tboot. | |
e8d776f2 | 113 | See Documentation/x86/intel_txt.rst for a description of how to enable |
31625340 JC |
114 | Intel TXT support in a kernel boot. |
115 | ||
116 | If you are unsure as to whether this is required, answer N. | |
117 | ||
788084ab | 118 | config LSM_MMAP_MIN_ADDR |
024e6cb4 | 119 | int "Low address space for LSM to protect from user allocation" |
788084ab | 120 | depends on SECURITY && SECURITY_SELINUX |
530b099d | 121 | default 32768 if ARM || (ARM64 && COMPAT) |
a58578e4 | 122 | default 65536 |
788084ab EP |
123 | help |
124 | This is the portion of low virtual memory which should be protected | |
125 | from userspace allocation. Keeping a user from writing to low pages | |
126 | can help reduce the impact of kernel NULL pointer bugs. | |
127 | ||
128 | For most ia64, ppc64 and x86 users with lots of address space | |
129 | a value of 65536 is reasonable and should cause no problems. | |
130 | On arm and other archs it should not be higher than 32768. | |
131 | Programs which use vm86 functionality or have some need to map | |
132 | this low address space will need the permission specific to the | |
133 | systems running LSM. | |
134 | ||
f5509cc1 KC |
135 | config HAVE_HARDENED_USERCOPY_ALLOCATOR |
136 | bool | |
137 | help | |
138 | The heap allocator implements __check_heap_object() for | |
139 | validating memory ranges against heap object sizes in | |
140 | support of CONFIG_HARDENED_USERCOPY. | |
141 | ||
f5509cc1 KC |
142 | config HARDENED_USERCOPY |
143 | bool "Harden memory copies between kernel and userspace" | |
6040e576 | 144 | depends on HAVE_HARDENED_USERCOPY_ALLOCATOR |
22ec1a2a | 145 | imply STRICT_DEVMEM |
f5509cc1 KC |
146 | help |
147 | This option checks for obviously wrong memory regions when | |
148 | copying memory to/from the kernel (via copy_to_user() and | |
149 | copy_from_user() functions) by rejecting memory ranges that | |
150 | are larger than the specified heap object, span multiple | |
99c55fb1 | 151 | separately allocated pages, are not on the process stack, |
1109a5d9 | 152 | or are part of the kernel text. This prevents entire classes |
f5509cc1 KC |
153 | of heap overflow exploits and similar kernel memory exposures. |
154 | ||
6974f0c4 DM |
155 | config FORTIFY_SOURCE |
156 | bool "Harden common str/mem functions against buffer overflows" | |
157 | depends on ARCH_HAS_FORTIFY_SOURCE | |
a52f8a59 | 158 | # https://bugs.llvm.org/show_bug.cgi?id=41459 |
281d0c96 KC |
159 | depends on !CC_IS_CLANG || CLANG_VERSION >= 120001 |
160 | # https://github.com/llvm/llvm-project/issues/53645 | |
161 | depends on !CC_IS_CLANG || !X86_32 | |
6974f0c4 DM |
162 | help |
163 | Detect overflows of buffers in common string and memory functions | |
164 | where the compiler can determine and validate the buffer sizes. | |
165 | ||
64e90a8a GKH |
166 | config STATIC_USERMODEHELPER |
167 | bool "Force all usermode helper calls through a single binary" | |
168 | help | |
169 | By default, the kernel can call many different userspace | |
170 | binary programs through the "usermode helper" kernel | |
171 | interface. Some of these binaries are statically defined | |
172 | either in the kernel code itself, or as a kernel configuration | |
173 | option. However, some of these are dynamically created at | |
174 | runtime, or can be modified after the kernel has started up. | |
175 | To provide an additional layer of security, route all of these | |
176 | calls through a single executable that can not have its name | |
177 | changed. | |
178 | ||
179 | Note, it is up to this single binary to then call the relevant | |
180 | "real" usermode helper binary, based on the first argument | |
181 | passed to it. If desired, this program can filter and pick | |
182 | and choose what real programs are called. | |
183 | ||
184 | If you wish for all usermode helper programs are to be | |
185 | disabled, choose this option and then set | |
186 | STATIC_USERMODEHELPER_PATH to an empty string. | |
187 | ||
188 | config STATIC_USERMODEHELPER_PATH | |
189 | string "Path to the static usermode helper binary" | |
190 | depends on STATIC_USERMODEHELPER | |
191 | default "/sbin/usermode-helper" | |
192 | help | |
193 | The binary called by the kernel when any usermode helper | |
194 | program is wish to be run. The "real" application's name will | |
195 | be in the first argument passed to this program on the command | |
196 | line. | |
197 | ||
198 | If you wish for all usermode helper programs to be disabled, | |
199 | specify an empty string here (i.e. ""). | |
200 | ||
8636a1f9 MY |
201 | source "security/selinux/Kconfig" |
202 | source "security/smack/Kconfig" | |
203 | source "security/tomoyo/Kconfig" | |
204 | source "security/apparmor/Kconfig" | |
205 | source "security/loadpin/Kconfig" | |
206 | source "security/yama/Kconfig" | |
aeca4e2c | 207 | source "security/safesetid/Kconfig" |
000d388e | 208 | source "security/lockdown/Kconfig" |
90945448 | 209 | source "security/landlock/Kconfig" |
1da177e4 | 210 | |
8636a1f9 | 211 | source "security/integrity/Kconfig" |
3323eec9 | 212 | |
2623c4fb KC |
213 | choice |
214 | prompt "First legacy 'major LSM' to be initialized" | |
215 | default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX | |
216 | default DEFAULT_SECURITY_SMACK if SECURITY_SMACK | |
217 | default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO | |
218 | default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR | |
219 | default DEFAULT_SECURITY_DAC | |
220 | ||
221 | help | |
222 | This choice is there only for converting CONFIG_DEFAULT_SECURITY | |
223 | in old kernel configs to CONFIG_LSM in new kernel configs. Don't | |
224 | change this choice unless you are creating a fresh kernel config, | |
225 | for this choice will be ignored after CONFIG_LSM has been set. | |
226 | ||
227 | Selects the legacy "major security module" that will be | |
228 | initialized first. Overridden by non-default CONFIG_LSM. | |
229 | ||
230 | config DEFAULT_SECURITY_SELINUX | |
231 | bool "SELinux" if SECURITY_SELINUX=y | |
232 | ||
233 | config DEFAULT_SECURITY_SMACK | |
234 | bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y | |
235 | ||
236 | config DEFAULT_SECURITY_TOMOYO | |
237 | bool "TOMOYO" if SECURITY_TOMOYO=y | |
238 | ||
239 | config DEFAULT_SECURITY_APPARMOR | |
240 | bool "AppArmor" if SECURITY_APPARMOR=y | |
241 | ||
242 | config DEFAULT_SECURITY_DAC | |
243 | bool "Unix Discretionary Access Controls" | |
244 | ||
245 | endchoice | |
246 | ||
13e735c0 KC |
247 | config LSM |
248 | string "Ordered list of enabled LSMs" | |
385975dc MS |
249 | default "landlock,lockdown,yama,loadpin,safesetid,integrity,smack,selinux,tomoyo,apparmor,bpf" if DEFAULT_SECURITY_SMACK |
250 | default "landlock,lockdown,yama,loadpin,safesetid,integrity,apparmor,selinux,smack,tomoyo,bpf" if DEFAULT_SECURITY_APPARMOR | |
251 | default "landlock,lockdown,yama,loadpin,safesetid,integrity,tomoyo,bpf" if DEFAULT_SECURITY_TOMOYO | |
252 | default "landlock,lockdown,yama,loadpin,safesetid,integrity,bpf" if DEFAULT_SECURITY_DAC | |
253 | default "landlock,lockdown,yama,loadpin,safesetid,integrity,selinux,smack,tomoyo,apparmor,bpf" | |
13e735c0 KC |
254 | help |
255 | A comma-separated list of LSMs, in initialization order. | |
79f7865d KC |
256 | Any LSMs left off this list will be ignored. This can be |
257 | controlled at boot with the "lsm=" parameter. | |
13e735c0 KC |
258 | |
259 | If unsure, leave this as the default. | |
260 | ||
9f671e58 KC |
261 | source "security/Kconfig.hardening" |
262 | ||
1da177e4 LT |
263 | endmenu |
264 |