1# 2# Security configuration 3# 4 5menu "Security options" 6 7source security/keys/Kconfig 8 9config 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 21config 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 34config SECURITY_WRITABLE_HOOKS 35 depends on SECURITY 36 bool 37 default n 38 39config 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 48config 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 57config 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 66config 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. 78 79config 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 88config INTEL_TXT 89 bool "Enable Intel(R) Trusted Execution Technology (Intel(R) TXT)" 90 depends on HAVE_INTEL_TXT 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 98 Intel TXT will provide higher assurance of system configuration and 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 107 it was configured with, especially since they may be responsible for 108 providing such assurances to VMs and services running on it. 109 110 See <http://www.intel.com/technology/security/> for more information 111 about Intel(R) TXT. 112 See <http://tboot.sourceforge.net> for more information about tboot. 113 See Documentation/intel_txt.txt for a description of how to enable 114 Intel TXT support in a kernel boot. 115 116 If you are unsure as to whether this is required, answer N. 117 118config LSM_MMAP_MIN_ADDR 119 int "Low address space for LSM to protect from user allocation" 120 depends on SECURITY && SECURITY_SELINUX 121 default 32768 if ARM || (ARM64 && COMPAT) 122 default 65536 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 135config 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 142config HARDENED_USERCOPY 143 bool "Harden memory copies between kernel and userspace" 144 depends on HAVE_HARDENED_USERCOPY_ALLOCATOR 145 select BUG 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 151 separately allocated pages, are not on the process stack, 152 or are part of the kernel text. This kills entire classes 153 of heap overflow exploits and similar kernel memory exposures. 154 155config HARDENED_USERCOPY_PAGESPAN 156 bool "Refuse to copy allocations that span multiple pages" 157 depends on HARDENED_USERCOPY 158 depends on EXPERT 159 help 160 When a multi-page allocation is done without __GFP_COMP, 161 hardened usercopy will reject attempts to copy it. There are, 162 however, several cases of this in the kernel that have not all 163 been removed. This config is intended to be used only while 164 trying to find such users. 165 166config FORTIFY_SOURCE 167 bool "Harden common str/mem functions against buffer overflows" 168 depends on ARCH_HAS_FORTIFY_SOURCE 169 help 170 Detect overflows of buffers in common string and memory functions 171 where the compiler can determine and validate the buffer sizes. 172 173config STATIC_USERMODEHELPER 174 bool "Force all usermode helper calls through a single binary" 175 help 176 By default, the kernel can call many different userspace 177 binary programs through the "usermode helper" kernel 178 interface. Some of these binaries are statically defined 179 either in the kernel code itself, or as a kernel configuration 180 option. However, some of these are dynamically created at 181 runtime, or can be modified after the kernel has started up. 182 To provide an additional layer of security, route all of these 183 calls through a single executable that can not have its name 184 changed. 185 186 Note, it is up to this single binary to then call the relevant 187 "real" usermode helper binary, based on the first argument 188 passed to it. If desired, this program can filter and pick 189 and choose what real programs are called. 190 191 If you wish for all usermode helper programs are to be 192 disabled, choose this option and then set 193 STATIC_USERMODEHELPER_PATH to an empty string. 194 195config STATIC_USERMODEHELPER_PATH 196 string "Path to the static usermode helper binary" 197 depends on STATIC_USERMODEHELPER 198 default "/sbin/usermode-helper" 199 help 200 The binary called by the kernel when any usermode helper 201 program is wish to be run. The "real" application's name will 202 be in the first argument passed to this program on the command 203 line. 204 205 If you wish for all usermode helper programs to be disabled, 206 specify an empty string here (i.e. ""). 207 208source security/selinux/Kconfig 209source security/smack/Kconfig 210source security/tomoyo/Kconfig 211source security/apparmor/Kconfig 212source security/loadpin/Kconfig 213source security/yama/Kconfig 214 215source security/integrity/Kconfig 216 217choice 218 prompt "Default security module" 219 default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX 220 default DEFAULT_SECURITY_SMACK if SECURITY_SMACK 221 default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO 222 default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR 223 default DEFAULT_SECURITY_DAC 224 225 help 226 Select the security module that will be used by default if the 227 kernel parameter security= is not specified. 228 229 config DEFAULT_SECURITY_SELINUX 230 bool "SELinux" if SECURITY_SELINUX=y 231 232 config DEFAULT_SECURITY_SMACK 233 bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y 234 235 config DEFAULT_SECURITY_TOMOYO 236 bool "TOMOYO" if SECURITY_TOMOYO=y 237 238 config DEFAULT_SECURITY_APPARMOR 239 bool "AppArmor" if SECURITY_APPARMOR=y 240 241 config DEFAULT_SECURITY_DAC 242 bool "Unix Discretionary Access Controls" 243 244endchoice 245 246config DEFAULT_SECURITY 247 string 248 default "selinux" if DEFAULT_SECURITY_SELINUX 249 default "smack" if DEFAULT_SECURITY_SMACK 250 default "tomoyo" if DEFAULT_SECURITY_TOMOYO 251 default "apparmor" if DEFAULT_SECURITY_APPARMOR 252 default "" if DEFAULT_SECURITY_DAC 253 254endmenu 255 256