2 # Security configuration
5 menu "Security options"
7 source security/keys/Kconfig
9 config SECURITY_DMESG_RESTRICT
10 bool "Restrict unprivileged access to the kernel syslog"
13 This enforces restrictions on unprivileged users reading the kernel
16 If this option is not selected, no restrictions will be enforced
17 unless the dmesg_restrict sysctl is explicitly set to (1).
19 If you are unsure how to answer this question, answer N.
21 config SECURITY_PERF_EVENTS_RESTRICT
22 bool "Restrict unprivileged use of performance events"
23 depends on PERF_EVENTS
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
31 bool "Enable different security models"
35 This allows you to choose different security modules to be
36 configured into your kernel.
38 If this option is not selected, the default Linux security
41 If you are unsure how to answer this question, answer N.
43 config SECURITY_WRITABLE_HOOKS
49 bool "Enable the securityfs filesystem"
51 This will build the securityfs filesystem. It is currently used by
52 the TPM bios character driver and IMA, an integrity provider. It is
53 not used by SELinux or SMACK.
55 If you are unsure how to answer this question, answer N.
57 config SECURITY_NETWORK
58 bool "Socket and Networking Security Hooks"
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.
66 config PAGE_TABLE_ISOLATION
67 bool "Remove the kernel mapping in user mode"
68 depends on X86_64 && !UML
71 This feature reduces the number of hardware side channels by
72 ensuring that the majority of kernel addresses are not mapped
75 See Documentation/x86/pti.txt for more details.
77 config SECURITY_INFINIBAND
78 bool "Infiniband Security Hooks"
79 depends on SECURITY && INFINIBAND
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.
86 config SECURITY_NETWORK_XFRM
87 bool "XFRM (IPSec) Networking Security Hooks"
88 depends on XFRM && SECURITY_NETWORK
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
97 If you are unsure how to answer this question, answer N.
100 bool "Security hooks for pathname based access control"
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.
109 bool "Enable Intel(R) Trusted Execution Technology (Intel(R) TXT)"
110 depends on HAVE_INTEL_TXT
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
118 Intel TXT will provide higher assurance of system configuration and
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.
125 Intel TXT also helps solve real end user concerns about having
126 confidence that their hardware is running the VMM or kernel that
127 it was configured with, especially since they may be responsible for
128 providing such assurances to VMs and services running on it.
130 See <http://www.intel.com/technology/security/> for more information
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.
136 If you are unsure as to whether this is required, answer N.
138 config LSM_MMAP_MIN_ADDR
139 int "Low address space for LSM to protect from user allocation"
140 depends on SECURITY && SECURITY_SELINUX
141 default 32768 if ARM || (ARM64 && COMPAT)
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.
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
155 config HAVE_HARDENED_USERCOPY_ALLOCATOR
158 The heap allocator implements __check_heap_object() for
159 validating memory ranges against heap object sizes in
160 support of CONFIG_HARDENED_USERCOPY.
162 config HARDENED_USERCOPY
163 bool "Harden memory copies between kernel and userspace"
164 depends on HAVE_HARDENED_USERCOPY_ALLOCATOR
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
172 separately allocated pages, are not on the process stack,
173 or are part of the kernel text. This kills entire classes
174 of heap overflow exploits and similar kernel memory exposures.
176 config HARDENED_USERCOPY_PAGESPAN
177 bool "Refuse to copy allocations that span multiple pages"
178 depends on HARDENED_USERCOPY
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.
187 config FORTIFY_SOURCE
188 bool "Harden common str/mem functions against buffer overflows"
189 depends on ARCH_HAS_FORTIFY_SOURCE
191 Detect overflows of buffers in common string and memory functions
192 where the compiler can determine and validate the buffer sizes.
194 config STATIC_USERMODEHELPER
195 bool "Force all usermode helper calls through a single binary"
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
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.
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.
216 config STATIC_USERMODEHELPER_PATH
217 string "Path to the static usermode helper binary"
218 depends on STATIC_USERMODEHELPER
219 default "/sbin/usermode-helper"
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
226 If you wish for all usermode helper programs to be disabled,
227 specify an empty string here (i.e. "").
229 source security/selinux/Kconfig
230 source security/smack/Kconfig
231 source security/tomoyo/Kconfig
232 source security/apparmor/Kconfig
233 source security/loadpin/Kconfig
234 source security/yama/Kconfig
236 source security/integrity/Kconfig
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
243 default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR
244 default DEFAULT_SECURITY_DAC
247 Select the security module that will be used by default if the
248 kernel parameter security= is not specified.
250 config DEFAULT_SECURITY_SELINUX
251 bool "SELinux" if SECURITY_SELINUX=y
253 config DEFAULT_SECURITY_SMACK
254 bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y
256 config DEFAULT_SECURITY_TOMOYO
257 bool "TOMOYO" if SECURITY_TOMOYO=y
259 config DEFAULT_SECURITY_APPARMOR
260 bool "AppArmor" if SECURITY_APPARMOR=y
262 config DEFAULT_SECURITY_DAC
263 bool "Unix Discretionary Access Controls"
267 config DEFAULT_SECURITY
269 default "selinux" if DEFAULT_SECURITY_SELINUX
270 default "smack" if DEFAULT_SECURITY_SMACK
271 default "tomoyo" if DEFAULT_SECURITY_TOMOYO
272 default "apparmor" if DEFAULT_SECURITY_APPARMOR
273 default "" if DEFAULT_SECURITY_DAC