1# SPDX-License-Identifier: GPL-2.0-only 2# 3# Security configuration 4# 5 6menu "Security options" 7 8source "security/keys/Kconfig" 9 10config 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 22choice 23 prompt "Allow /proc/pid/mem access override" 24 default PROC_MEM_ALWAYS_FORCE 25 help 26 Traditionally /proc/pid/mem allows users to override memory 27 permissions for users like ptrace, assuming they have ptrace 28 capability. 29 30 This allows people to limit that - either never override, or 31 require actual active ptrace attachment. 32 33 Defaults to the traditional behavior (for now) 34 35config PROC_MEM_ALWAYS_FORCE 36 bool "Traditional /proc/pid/mem behavior" 37 help 38 This allows /proc/pid/mem accesses to override memory mapping 39 permissions if you have ptrace access rights. 40 41config PROC_MEM_FORCE_PTRACE 42 bool "Require active ptrace() use for access override" 43 help 44 This allows /proc/pid/mem accesses to override memory mapping 45 permissions for active ptracers like gdb. 46 47config PROC_MEM_NO_FORCE 48 bool "Never" 49 help 50 Never override memory mapping permissions 51 52endchoice 53 54config MSEAL_SYSTEM_MAPPINGS 55 bool "mseal system mappings" 56 depends on 64BIT 57 depends on ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS 58 depends on !CHECKPOINT_RESTORE 59 help 60 Apply mseal on system mappings. 61 The system mappings includes vdso, vvar, vvar_vclock, 62 vectors (arm compat-mode), sigpage (arm compat-mode), uprobes. 63 64 A 64-bit kernel is required for the memory sealing feature. 65 No specific hardware features from the CPU are needed. 66 67 WARNING: This feature breaks programs which rely on relocating 68 or unmapping system mappings. Known broken software at the time 69 of writing includes CHECKPOINT_RESTORE, UML, gVisor, rr. Therefore 70 this config can't be enabled universally. 71 72 For complete descriptions of memory sealing, please see 73 Documentation/userspace-api/mseal.rst 74 75config SECURITY 76 bool "Enable different security models" 77 depends on SYSFS 78 depends on MULTIUSER 79 help 80 This allows you to choose different security modules to be 81 configured into your kernel. 82 83 If this option is not selected, the default Linux security 84 model will be used. 85 86 If you are unsure how to answer this question, answer N. 87 88config HAS_SECURITY_AUDIT 89 def_bool y 90 depends on AUDIT 91 depends on SECURITY 92 93config SECURITYFS 94 bool "Enable the securityfs filesystem" 95 help 96 This will build the securityfs filesystem. It is currently used by 97 various security modules (AppArmor, IMA, SafeSetID, TOMOYO, TPM). 98 99 If you are unsure how to answer this question, answer N. 100 101config SECURITY_NETWORK 102 bool "Socket and Networking Security Hooks" 103 depends on SECURITY 104 help 105 This enables the socket and networking security hooks. 106 If enabled, a security module can use these hooks to 107 implement socket and networking access controls. 108 If you are unsure how to answer this question, answer N. 109 110config SECURITY_INFINIBAND 111 bool "Infiniband Security Hooks" 112 depends on SECURITY && INFINIBAND 113 help 114 This enables the Infiniband security hooks. 115 If enabled, a security module can use these hooks to 116 implement Infiniband access controls. 117 If you are unsure how to answer this question, answer N. 118 119config SECURITY_NETWORK_XFRM 120 bool "XFRM (IPSec) Networking Security Hooks" 121 depends on XFRM && SECURITY_NETWORK 122 help 123 This enables the XFRM (IPSec) networking security hooks. 124 If enabled, a security module can use these hooks to 125 implement per-packet access controls based on labels 126 derived from IPSec policy. Non-IPSec communications are 127 designated as unlabelled, and only sockets authorized 128 to communicate unlabelled data can send without using 129 IPSec. 130 If you are unsure how to answer this question, answer N. 131 132config SECURITY_PATH 133 bool "Security hooks for pathname based access control" 134 depends on SECURITY 135 help 136 This enables the security hooks for pathname based access control. 137 If enabled, a security module can use these hooks to 138 implement pathname based access controls. 139 If you are unsure how to answer this question, answer N. 140 141config INTEL_TXT 142 bool "Enable Intel(R) Trusted Execution Technology (Intel(R) TXT)" 143 depends on HAVE_INTEL_TXT 144 help 145 This option enables support for booting the kernel with the 146 Trusted Boot (tboot) module. This will utilize 147 Intel(R) Trusted Execution Technology to perform a measured launch 148 of the kernel. If the system does not support Intel(R) TXT, this 149 will have no effect. 150 151 Intel TXT will provide higher assurance of system configuration and 152 initial state as well as data reset protection. This is used to 153 create a robust initial kernel measurement and verification, which 154 helps to ensure that kernel security mechanisms are functioning 155 correctly. This level of protection requires a root of trust outside 156 of the kernel itself. 157 158 Intel TXT also helps solve real end user concerns about having 159 confidence that their hardware is running the VMM or kernel that 160 it was configured with, especially since they may be responsible for 161 providing such assurances to VMs and services running on it. 162 163 See <https://www.intel.com/technology/security/> for more information 164 about Intel(R) TXT. 165 See <http://tboot.sourceforge.net> for more information about tboot. 166 See Documentation/arch/x86/intel_txt.rst for a description of how to enable 167 Intel TXT support in a kernel boot. 168 169 If you are unsure as to whether this is required, answer N. 170 171config LSM_MMAP_MIN_ADDR 172 int "Low address space for LSM to protect from user allocation" 173 depends on SECURITY && SECURITY_SELINUX 174 default 32768 if ARM || (ARM64 && COMPAT) 175 default 65536 176 help 177 This is the portion of low virtual memory which should be protected 178 from userspace allocation. Keeping a user from writing to low pages 179 can help reduce the impact of kernel NULL pointer bugs. 180 181 For most ia64, ppc64 and x86 users with lots of address space 182 a value of 65536 is reasonable and should cause no problems. 183 On arm and other archs it should not be higher than 32768. 184 Programs which use vm86 functionality or have some need to map 185 this low address space will need the permission specific to the 186 systems running LSM. 187 188config STATIC_USERMODEHELPER 189 bool "Force all usermode helper calls through a single binary" 190 help 191 By default, the kernel can call many different userspace 192 binary programs through the "usermode helper" kernel 193 interface. Some of these binaries are statically defined 194 either in the kernel code itself, or as a kernel configuration 195 option. However, some of these are dynamically created at 196 runtime, or can be modified after the kernel has started up. 197 To provide an additional layer of security, route all of these 198 calls through a single executable that can not have its name 199 changed. 200 201 Note, it is up to this single binary to then call the relevant 202 "real" usermode helper binary, based on the first argument 203 passed to it. If desired, this program can filter and pick 204 and choose what real programs are called. 205 206 If you wish for all usermode helper programs are to be 207 disabled, choose this option and then set 208 STATIC_USERMODEHELPER_PATH to an empty string. 209 210config STATIC_USERMODEHELPER_PATH 211 string "Path to the static usermode helper binary" 212 depends on STATIC_USERMODEHELPER 213 default "/sbin/usermode-helper" 214 help 215 The binary called by the kernel when any usermode helper 216 program is wish to be run. The "real" application's name will 217 be in the first argument passed to this program on the command 218 line. 219 220 If you wish for all usermode helper programs to be disabled, 221 specify an empty string here (i.e. ""). 222 223source "security/selinux/Kconfig" 224source "security/smack/Kconfig" 225source "security/tomoyo/Kconfig" 226source "security/apparmor/Kconfig" 227source "security/loadpin/Kconfig" 228source "security/yama/Kconfig" 229source "security/safesetid/Kconfig" 230source "security/lockdown/Kconfig" 231source "security/landlock/Kconfig" 232source "security/ipe/Kconfig" 233 234source "security/integrity/Kconfig" 235 236choice 237 prompt "First legacy 'major LSM' to be initialized" 238 default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX 239 default DEFAULT_SECURITY_SMACK if SECURITY_SMACK 240 default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO 241 default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR 242 default DEFAULT_SECURITY_DAC 243 244 help 245 This choice is there only for converting CONFIG_DEFAULT_SECURITY 246 in old kernel configs to CONFIG_LSM in new kernel configs. Don't 247 change this choice unless you are creating a fresh kernel config, 248 for this choice will be ignored after CONFIG_LSM has been set. 249 250 Selects the legacy "major security module" that will be 251 initialized first. Overridden by non-default CONFIG_LSM. 252 253 config DEFAULT_SECURITY_SELINUX 254 bool "SELinux" if SECURITY_SELINUX=y 255 256 config DEFAULT_SECURITY_SMACK 257 bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y 258 259 config DEFAULT_SECURITY_TOMOYO 260 bool "TOMOYO" if SECURITY_TOMOYO=y 261 262 config DEFAULT_SECURITY_APPARMOR 263 bool "AppArmor" if SECURITY_APPARMOR=y 264 265 config DEFAULT_SECURITY_DAC 266 bool "Unix Discretionary Access Controls" 267 268endchoice 269 270config LSM 271 string "Ordered list of enabled LSMs" 272 default "landlock,lockdown,yama,loadpin,safesetid,smack,selinux,tomoyo,apparmor,ipe,bpf" if DEFAULT_SECURITY_SMACK 273 default "landlock,lockdown,yama,loadpin,safesetid,apparmor,selinux,smack,tomoyo,ipe,bpf" if DEFAULT_SECURITY_APPARMOR 274 default "landlock,lockdown,yama,loadpin,safesetid,tomoyo,ipe,bpf" if DEFAULT_SECURITY_TOMOYO 275 default "landlock,lockdown,yama,loadpin,safesetid,ipe,bpf" if DEFAULT_SECURITY_DAC 276 default "landlock,lockdown,yama,loadpin,safesetid,selinux,smack,tomoyo,apparmor,ipe,bpf" 277 help 278 A comma-separated list of LSMs, in initialization order. 279 Any LSMs left off this list, except for those with order 280 LSM_ORDER_FIRST and LSM_ORDER_LAST, which are always enabled 281 if selected in the kernel configuration, will be ignored. 282 This can be controlled at boot with the "lsm=" parameter. 283 284 If unsure, leave this as the default. 285 286source "security/Kconfig.hardening" 287 288endmenu 289 290