1 # SPDX-License-Identifier: GPL-2.0-only 1 # SPDX-License-Identifier: GPL-2.0-only 2 # 2 # 3 # Security configuration 3 # Security configuration 4 # 4 # 5 5 6 menu "Security options" 6 menu "Security options" 7 7 8 source "security/keys/Kconfig" 8 source "security/keys/Kconfig" 9 9 10 config SECURITY_DMESG_RESTRICT 10 config SECURITY_DMESG_RESTRICT 11 bool "Restrict unprivileged access to 11 bool "Restrict unprivileged access to the kernel syslog" 12 default n 12 default n 13 help 13 help 14 This enforces restrictions on unpriv 14 This enforces restrictions on unprivileged users reading the kernel 15 syslog via dmesg(8). 15 syslog via dmesg(8). 16 16 17 If this option is not selected, no r 17 If this option is not selected, no restrictions will be enforced 18 unless the dmesg_restrict sysctl is 18 unless the dmesg_restrict sysctl is explicitly set to (1). 19 19 20 If you are unsure how to answer this 20 If you are unsure how to answer this question, answer N. 21 21 22 choice 22 choice 23 prompt "Allow /proc/pid/mem access ove 23 prompt "Allow /proc/pid/mem access override" 24 default PROC_MEM_ALWAYS_FORCE 24 default PROC_MEM_ALWAYS_FORCE 25 help 25 help 26 Traditionally /proc/pid/mem allows u 26 Traditionally /proc/pid/mem allows users to override memory 27 permissions for users like ptrace, a 27 permissions for users like ptrace, assuming they have ptrace 28 capability. 28 capability. 29 29 30 This allows people to limit that - e 30 This allows people to limit that - either never override, or 31 require actual active ptrace attachm 31 require actual active ptrace attachment. 32 32 33 Defaults to the traditional behavior 33 Defaults to the traditional behavior (for now) 34 34 35 config PROC_MEM_ALWAYS_FORCE 35 config PROC_MEM_ALWAYS_FORCE 36 bool "Traditional /proc/pid/mem behavi 36 bool "Traditional /proc/pid/mem behavior" 37 help 37 help 38 This allows /proc/pid/mem accesses t 38 This allows /proc/pid/mem accesses to override memory mapping 39 permissions if you have ptrace acces 39 permissions if you have ptrace access rights. 40 40 41 config PROC_MEM_FORCE_PTRACE 41 config PROC_MEM_FORCE_PTRACE 42 bool "Require active ptrace() use for 42 bool "Require active ptrace() use for access override" 43 help 43 help 44 This allows /proc/pid/mem accesses t 44 This allows /proc/pid/mem accesses to override memory mapping 45 permissions for active ptracers like 45 permissions for active ptracers like gdb. 46 46 47 config PROC_MEM_NO_FORCE 47 config PROC_MEM_NO_FORCE 48 bool "Never" 48 bool "Never" 49 help 49 help 50 Never override memory mapping permis 50 Never override memory mapping permissions 51 51 52 endchoice 52 endchoice 53 53 54 config SECURITY 54 config SECURITY 55 bool "Enable different security models 55 bool "Enable different security models" 56 depends on SYSFS 56 depends on SYSFS 57 depends on MULTIUSER 57 depends on MULTIUSER 58 help 58 help 59 This allows you to choose different 59 This allows you to choose different security modules to be 60 configured into your kernel. 60 configured into your kernel. 61 61 62 If this option is not selected, the 62 If this option is not selected, the default Linux security 63 model will be used. 63 model will be used. 64 64 65 If you are unsure how to answer this 65 If you are unsure how to answer this question, answer N. 66 66 67 config SECURITYFS 67 config SECURITYFS 68 bool "Enable the securityfs filesystem 68 bool "Enable the securityfs filesystem" 69 help 69 help 70 This will build the securityfs files 70 This will build the securityfs filesystem. It is currently used by 71 various security modules (AppArmor, 71 various security modules (AppArmor, IMA, SafeSetID, TOMOYO, TPM). 72 72 73 If you are unsure how to answer this 73 If you are unsure how to answer this question, answer N. 74 74 75 config SECURITY_NETWORK 75 config SECURITY_NETWORK 76 bool "Socket and Networking Security H 76 bool "Socket and Networking Security Hooks" 77 depends on SECURITY 77 depends on SECURITY 78 help 78 help 79 This enables the socket and networki 79 This enables the socket and networking security hooks. 80 If enabled, a security module can us 80 If enabled, a security module can use these hooks to 81 implement socket and networking acce 81 implement socket and networking access controls. 82 If you are unsure how to answer this 82 If you are unsure how to answer this question, answer N. 83 83 84 config SECURITY_INFINIBAND 84 config SECURITY_INFINIBAND 85 bool "Infiniband Security Hooks" 85 bool "Infiniband Security Hooks" 86 depends on SECURITY && INFINIBAND 86 depends on SECURITY && INFINIBAND 87 help 87 help 88 This enables the Infiniband security 88 This enables the Infiniband security hooks. 89 If enabled, a security module can us 89 If enabled, a security module can use these hooks to 90 implement Infiniband access controls 90 implement Infiniband access controls. 91 If you are unsure how to answer this 91 If you are unsure how to answer this question, answer N. 92 92 93 config SECURITY_NETWORK_XFRM 93 config SECURITY_NETWORK_XFRM 94 bool "XFRM (IPSec) Networking Security 94 bool "XFRM (IPSec) Networking Security Hooks" 95 depends on XFRM && SECURITY_NETWORK 95 depends on XFRM && SECURITY_NETWORK 96 help 96 help 97 This enables the XFRM (IPSec) networ 97 This enables the XFRM (IPSec) networking security hooks. 98 If enabled, a security module can us 98 If enabled, a security module can use these hooks to 99 implement per-packet access controls 99 implement per-packet access controls based on labels 100 derived from IPSec policy. Non-IPSe 100 derived from IPSec policy. Non-IPSec communications are 101 designated as unlabelled, and only s 101 designated as unlabelled, and only sockets authorized 102 to communicate unlabelled data can s 102 to communicate unlabelled data can send without using 103 IPSec. 103 IPSec. 104 If you are unsure how to answer this 104 If you are unsure how to answer this question, answer N. 105 105 106 config SECURITY_PATH 106 config SECURITY_PATH 107 bool "Security hooks for pathname base 107 bool "Security hooks for pathname based access control" 108 depends on SECURITY 108 depends on SECURITY 109 help 109 help 110 This enables the security hooks for 110 This enables the security hooks for pathname based access control. 111 If enabled, a security module can us 111 If enabled, a security module can use these hooks to 112 implement pathname based access cont 112 implement pathname based access controls. 113 If you are unsure how to answer this 113 If you are unsure how to answer this question, answer N. 114 114 115 config INTEL_TXT 115 config INTEL_TXT 116 bool "Enable Intel(R) Trusted Executio 116 bool "Enable Intel(R) Trusted Execution Technology (Intel(R) TXT)" 117 depends on HAVE_INTEL_TXT 117 depends on HAVE_INTEL_TXT 118 help 118 help 119 This option enables support for boot 119 This option enables support for booting the kernel with the 120 Trusted Boot (tboot) module. This wi 120 Trusted Boot (tboot) module. This will utilize 121 Intel(R) Trusted Execution Technolog 121 Intel(R) Trusted Execution Technology to perform a measured launch 122 of the kernel. If the system does no 122 of the kernel. If the system does not support Intel(R) TXT, this 123 will have no effect. 123 will have no effect. 124 124 125 Intel TXT will provide higher assura 125 Intel TXT will provide higher assurance of system configuration and 126 initial state as well as data reset 126 initial state as well as data reset protection. This is used to 127 create a robust initial kernel measu 127 create a robust initial kernel measurement and verification, which 128 helps to ensure that kernel security 128 helps to ensure that kernel security mechanisms are functioning 129 correctly. This level of protection 129 correctly. This level of protection requires a root of trust outside 130 of the kernel itself. 130 of the kernel itself. 131 131 132 Intel TXT also helps solve real end 132 Intel TXT also helps solve real end user concerns about having 133 confidence that their hardware is ru 133 confidence that their hardware is running the VMM or kernel that 134 it was configured with, especially s 134 it was configured with, especially since they may be responsible for 135 providing such assurances to VMs and 135 providing such assurances to VMs and services running on it. 136 136 137 See <https://www.intel.com/technolog 137 See <https://www.intel.com/technology/security/> for more information 138 about Intel(R) TXT. 138 about Intel(R) TXT. 139 See <http://tboot.sourceforge.net> f 139 See <http://tboot.sourceforge.net> for more information about tboot. 140 See Documentation/arch/x86/intel_txt 140 See Documentation/arch/x86/intel_txt.rst for a description of how to enable 141 Intel TXT support in a kernel boot. 141 Intel TXT support in a kernel boot. 142 142 143 If you are unsure as to whether this 143 If you are unsure as to whether this is required, answer N. 144 144 145 config LSM_MMAP_MIN_ADDR 145 config LSM_MMAP_MIN_ADDR 146 int "Low address space for LSM to prot 146 int "Low address space for LSM to protect from user allocation" 147 depends on SECURITY && SECURITY_SELINU 147 depends on SECURITY && SECURITY_SELINUX 148 default 32768 if ARM || (ARM64 && COMP 148 default 32768 if ARM || (ARM64 && COMPAT) 149 default 65536 149 default 65536 150 help 150 help 151 This is the portion of low virtual m 151 This is the portion of low virtual memory which should be protected 152 from userspace allocation. Keeping 152 from userspace allocation. Keeping a user from writing to low pages 153 can help reduce the impact of kernel 153 can help reduce the impact of kernel NULL pointer bugs. 154 154 155 For most ia64, ppc64 and x86 users w 155 For most ia64, ppc64 and x86 users with lots of address space 156 a value of 65536 is reasonable and s 156 a value of 65536 is reasonable and should cause no problems. 157 On arm and other archs it should not 157 On arm and other archs it should not be higher than 32768. 158 Programs which use vm86 functionalit 158 Programs which use vm86 functionality or have some need to map 159 this low address space will need the 159 this low address space will need the permission specific to the 160 systems running LSM. 160 systems running LSM. 161 161 162 config HARDENED_USERCOPY 162 config HARDENED_USERCOPY 163 bool "Harden memory copies between ker 163 bool "Harden memory copies between kernel and userspace" 164 imply STRICT_DEVMEM 164 imply STRICT_DEVMEM 165 help 165 help 166 This option checks for obviously wro 166 This option checks for obviously wrong memory regions when 167 copying memory to/from the kernel (v 167 copying memory to/from the kernel (via copy_to_user() and 168 copy_from_user() functions) by rejec 168 copy_from_user() functions) by rejecting memory ranges that 169 are larger than the specified heap o 169 are larger than the specified heap object, span multiple 170 separately allocated pages, are not 170 separately allocated pages, are not on the process stack, 171 or are part of the kernel text. This 171 or are part of the kernel text. This prevents entire classes 172 of heap overflow exploits and simila 172 of heap overflow exploits and similar kernel memory exposures. 173 173 174 config FORTIFY_SOURCE 174 config FORTIFY_SOURCE 175 bool "Harden common str/mem functions 175 bool "Harden common str/mem functions against buffer overflows" 176 depends on ARCH_HAS_FORTIFY_SOURCE 176 depends on ARCH_HAS_FORTIFY_SOURCE >> 177 # https://bugs.llvm.org/show_bug.cgi?id=41459 >> 178 depends on !CC_IS_CLANG || CLANG_VERSION >= 120001 177 # https://github.com/llvm/llvm-project 179 # https://github.com/llvm/llvm-project/issues/53645 178 depends on !CC_IS_CLANG || !X86_32 180 depends on !CC_IS_CLANG || !X86_32 179 help 181 help 180 Detect overflows of buffers in commo 182 Detect overflows of buffers in common string and memory functions 181 where the compiler can determine and 183 where the compiler can determine and validate the buffer sizes. 182 184 183 config STATIC_USERMODEHELPER 185 config STATIC_USERMODEHELPER 184 bool "Force all usermode helper calls 186 bool "Force all usermode helper calls through a single binary" 185 help 187 help 186 By default, the kernel can call many 188 By default, the kernel can call many different userspace 187 binary programs through the "usermod 189 binary programs through the "usermode helper" kernel 188 interface. Some of these binaries a 190 interface. Some of these binaries are statically defined 189 either in the kernel code itself, or 191 either in the kernel code itself, or as a kernel configuration 190 option. However, some of these are 192 option. However, some of these are dynamically created at 191 runtime, or can be modified after th 193 runtime, or can be modified after the kernel has started up. 192 To provide an additional layer of se 194 To provide an additional layer of security, route all of these 193 calls through a single executable th 195 calls through a single executable that can not have its name 194 changed. 196 changed. 195 197 196 Note, it is up to this single binary 198 Note, it is up to this single binary to then call the relevant 197 "real" usermode helper binary, based 199 "real" usermode helper binary, based on the first argument 198 passed to it. If desired, this prog 200 passed to it. If desired, this program can filter and pick 199 and choose what real programs are ca 201 and choose what real programs are called. 200 202 201 If you wish for all usermode helper 203 If you wish for all usermode helper programs are to be 202 disabled, choose this option and the 204 disabled, choose this option and then set 203 STATIC_USERMODEHELPER_PATH to an emp 205 STATIC_USERMODEHELPER_PATH to an empty string. 204 206 205 config STATIC_USERMODEHELPER_PATH 207 config STATIC_USERMODEHELPER_PATH 206 string "Path to the static usermode he 208 string "Path to the static usermode helper binary" 207 depends on STATIC_USERMODEHELPER 209 depends on STATIC_USERMODEHELPER 208 default "/sbin/usermode-helper" 210 default "/sbin/usermode-helper" 209 help 211 help 210 The binary called by the kernel when 212 The binary called by the kernel when any usermode helper 211 program is wish to be run. The "rea 213 program is wish to be run. The "real" application's name will 212 be in the first argument passed to t 214 be in the first argument passed to this program on the command 213 line. 215 line. 214 216 215 If you wish for all usermode helper 217 If you wish for all usermode helper programs to be disabled, 216 specify an empty string here (i.e. " 218 specify an empty string here (i.e. ""). 217 219 218 source "security/selinux/Kconfig" 220 source "security/selinux/Kconfig" 219 source "security/smack/Kconfig" 221 source "security/smack/Kconfig" 220 source "security/tomoyo/Kconfig" 222 source "security/tomoyo/Kconfig" 221 source "security/apparmor/Kconfig" 223 source "security/apparmor/Kconfig" 222 source "security/loadpin/Kconfig" 224 source "security/loadpin/Kconfig" 223 source "security/yama/Kconfig" 225 source "security/yama/Kconfig" 224 source "security/safesetid/Kconfig" 226 source "security/safesetid/Kconfig" 225 source "security/lockdown/Kconfig" 227 source "security/lockdown/Kconfig" 226 source "security/landlock/Kconfig" 228 source "security/landlock/Kconfig" 227 229 228 source "security/integrity/Kconfig" 230 source "security/integrity/Kconfig" 229 231 230 choice 232 choice 231 prompt "First legacy 'major LSM' to be 233 prompt "First legacy 'major LSM' to be initialized" 232 default DEFAULT_SECURITY_SELINUX if SE 234 default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX 233 default DEFAULT_SECURITY_SMACK if SECU 235 default DEFAULT_SECURITY_SMACK if SECURITY_SMACK 234 default DEFAULT_SECURITY_TOMOYO if SEC 236 default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO 235 default DEFAULT_SECURITY_APPARMOR if S 237 default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR 236 default DEFAULT_SECURITY_DAC 238 default DEFAULT_SECURITY_DAC 237 239 238 help 240 help 239 This choice is there only for conver 241 This choice is there only for converting CONFIG_DEFAULT_SECURITY 240 in old kernel configs to CONFIG_LSM 242 in old kernel configs to CONFIG_LSM in new kernel configs. Don't 241 change this choice unless you are cr 243 change this choice unless you are creating a fresh kernel config, 242 for this choice will be ignored afte 244 for this choice will be ignored after CONFIG_LSM has been set. 243 245 244 Selects the legacy "major security m 246 Selects the legacy "major security module" that will be 245 initialized first. Overridden by non 247 initialized first. Overridden by non-default CONFIG_LSM. 246 248 247 config DEFAULT_SECURITY_SELINUX 249 config DEFAULT_SECURITY_SELINUX 248 bool "SELinux" if SECURITY_SEL 250 bool "SELinux" if SECURITY_SELINUX=y 249 251 250 config DEFAULT_SECURITY_SMACK 252 config DEFAULT_SECURITY_SMACK 251 bool "Simplified Mandatory Acc 253 bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y 252 254 253 config DEFAULT_SECURITY_TOMOYO 255 config DEFAULT_SECURITY_TOMOYO 254 bool "TOMOYO" if SECURITY_TOMO 256 bool "TOMOYO" if SECURITY_TOMOYO=y 255 257 256 config DEFAULT_SECURITY_APPARMOR 258 config DEFAULT_SECURITY_APPARMOR 257 bool "AppArmor" if SECURITY_AP 259 bool "AppArmor" if SECURITY_APPARMOR=y 258 260 259 config DEFAULT_SECURITY_DAC 261 config DEFAULT_SECURITY_DAC 260 bool "Unix Discretionary Acces 262 bool "Unix Discretionary Access Controls" 261 263 262 endchoice 264 endchoice 263 265 264 config LSM 266 config LSM 265 string "Ordered list of enabled LSMs" 267 string "Ordered list of enabled LSMs" 266 default "landlock,lockdown,yama,loadpi 268 default "landlock,lockdown,yama,loadpin,safesetid,smack,selinux,tomoyo,apparmor,bpf" if DEFAULT_SECURITY_SMACK 267 default "landlock,lockdown,yama,loadpi 269 default "landlock,lockdown,yama,loadpin,safesetid,apparmor,selinux,smack,tomoyo,bpf" if DEFAULT_SECURITY_APPARMOR 268 default "landlock,lockdown,yama,loadpi 270 default "landlock,lockdown,yama,loadpin,safesetid,tomoyo,bpf" if DEFAULT_SECURITY_TOMOYO 269 default "landlock,lockdown,yama,loadpi 271 default "landlock,lockdown,yama,loadpin,safesetid,bpf" if DEFAULT_SECURITY_DAC 270 default "landlock,lockdown,yama,loadpi 272 default "landlock,lockdown,yama,loadpin,safesetid,selinux,smack,tomoyo,apparmor,bpf" 271 help 273 help 272 A comma-separated list of LSMs, in i 274 A comma-separated list of LSMs, in initialization order. 273 Any LSMs left off this list, except 275 Any LSMs left off this list, except for those with order 274 LSM_ORDER_FIRST and LSM_ORDER_LAST, 276 LSM_ORDER_FIRST and LSM_ORDER_LAST, which are always enabled 275 if selected in the kernel configurat 277 if selected in the kernel configuration, will be ignored. 276 This can be controlled at boot with 278 This can be controlled at boot with the "lsm=" parameter. 277 279 278 If unsure, leave this as the default 280 If unsure, leave this as the default. 279 281 280 source "security/Kconfig.hardening" 282 source "security/Kconfig.hardening" 281 283 282 source "security/ccsecurity/Kconfig" 284 source "security/ccsecurity/Kconfig" 283 285 284 endmenu 286 endmenu 285 287
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